Automotive Assembly

Automotive Engineering Terminology List

We have developed a comprehensive list of automotive, manufacturing and quality terms that you should know if you want to become an Automotive Engineer. The Automotive Engineering Terminology List has been developed  by a crack team of our best Automotive Engineers and we have tried to cover every topic we could think of.

If you have something we should add to the list, or want something explained better just let us know!

Automotive Engineering Terminology – A – Z

Here is all the automotive engineering terminology you need to know, arranged alphabetically. If you come across an acronym you don’t know or a phrase that is too confusing in your job or studies, let us help you our! We will continue to add to our engineering terminology list weekly. Feel free to recommend more terms for our list!

4WD (Four Wheel Drive) – Four wheel drive vehicles apply power to all four vehicles at the same time and there are typically two settings (low/high) depending on the speed and driving conditions. 4WD differs from AWD in that 4WD has set power ratios for each wheel and AWD will sense the driving conditions and distribute power the wheels that have the best traction.

5S Methodology – The 5 Step methodology includes Seiri or Sort where you do a first pass of a process or area and discard anything that is not essential, next is Seiton or Straighten which puts the remaining items in order, third is Seison or Shine where the area is cleaned and a process put in place to maintain the cleanliness, fourth is Seiketsu or Standardize that creates habits to keep things in order and clean and finally is Shitsuke or Sustain where the procedures developed in the fourth step must be put in place and maintained. 5S methodology is used as a continuous improvement process to make process more efficient and streamlined.

80/20 Rule – The 80/20 rule, which also goes by the name The Principle of Factor Scarcity or the Law of the Vital Few, says that 80% of the results comes from just 20% of the actions. This principle is used in the automotive engineering field when doing Pareto Analysis on quality data from production

8D Problem Solving – The8D problem solving methodology is a process used by automotive engineers to resolve a quality issue and allows the engineering team to identify, correct and stop the problem recurring in the future. The steps in the process include: plan, form a team, define the problem, develop a containment plan, identify root cause, implement a permanent corrective action, validate the corrective action, put preventative measures in place and finally celebrate the success with the team.

Aftermarket – Aftermarket describes the market for service, replacement, accessories and any additional equipment that is installed on a vehicle after it leaves final production. These products typically enhance the performance or appearance of the vehicle and are produced and marketed both by the original manufacturer and outside vendors.

AIAGAutomotive Industry Action Group (AIAG) is a consortium of industry experts from major car manufacturers that collaborate to develop quality processes, establish global standards for development and production and harmonize business practices between companies. The policies and procedures that AIAG have developed are applied up and down the supply chain for all areas of automotive engineering.

ANSI (American National Standards Institute) – The American National Standards Institute is the overall voice of the US Standards and conformance system that works to create norms and guidelines used by all business sectors within the United States with the mission to increase global competitiveness by creating conformity and integrity with assessment systems used by the standards teams.

A-Pillar – Pillar that joins the windshield to the front-most side windows

APQP (Advanced Product Quality Planning) APQP is a checklist of procedures and techniques used to develop and launch a product in the automotive industry. The APQP looks at all areas of the development process from design to production and end of life.

Assembly – The term assembly can be a general term for an assembled component or an ‘assembly’. (A part would be a single unit and the assembly would be the group assembled together) This can also refer to the overall process or department responsible for assembling a component or entire vehicle.

Audit–An audit is the process where quality engineers or representatives review the policies and procedures of the automotive company to ensure they meet industry requirements and are maintaining records as required to remain certified in the industry.

Automatic Transmission – Automatic transmission system within a vehicle will automatically change gears within the transmission in response to the vehicle speed.

AWD (All-Wheel Drive) – All wheel drive vehicles have a percentage of power sent to all wheels on the vehicle for propulsion.

Axial – Forces or direction that is applied along the axis. If you picture a wheel on a car, axial would be the direction the axle is running, though the center of the wheel.

Axis to dash – The relationship between the front wheels and the windshield of a vehicle which varies depending on whether the vehicle is front or rear wheel drive.

Backlash – A reaction or recoil between parts that do not fit together properly, slop in mechanical system usually in gear that results in parts not fitting together as they should. (Usually a negative effect)

Bearing – An anti-friction device that is located between two moving parts of an automobile (example: wheel bearing) that helps to minimize wear and friction. Usually a bearing refers to two or more moving parts that allow a part to slide against another. Roller bearings, ball bearings and Needle bearings all use a round intermediate object to “roll” the parts against themselves.

Beltline – Line from the hood that runs below the bottom edge of the windows and ends at the trunk.

Benchmarking–The process of reverse engineering a competitor’s product to assess how your product compares to their design and technology. Benchmarking gives insight into new designs, materials and technologies as well as new engineering ideas that can be used to improve a product design. Cars are either benchmarked cooperatively by two companies looking for mutual gain, or are benchmarked by purchasing a product to analyze and gain insights on technological advantages.

BOBs and WOWs – Acronym for Best of Best and Worst of Worst. BOBs and WOWs come into effect when you are analyzing a defect that occurs intermittently in a particular process. The process involves analyzing the best of the best parts that are found against  the worst of the worst to see if there is a significant measurable difference that then can be acted on.  For example, if an oscillation is detected in a part test but does not always occur, you would set aside the 5 parts with the least oscillation (Best of Best) and the 5 with the worst oscillation (Worst of Worst) and then 100% measure the parts to see what the differences are.

Body – Outer portions of a vehicle (excluding the chassis) including, fiberglass, metal, etc. that form the outer shell of the vehicle.

Body In White (BIW) – This is an industry term that describes the metal body of the car prior to any assembly or paint job applied. The Body in White is the product that comes directly from the body shop in an automotive assembly plant.

Body wide line – Lateral lines where the maximum width of the vehicle can be measured (mirrors excluded).

BOM (Bill of Material) –A listing of all the materials, subassemblies and components that are used to assemble a top level assembly. Usually a BOM refers to the top level assembly of a particular product or vehicle.  BOM can also be used to describe the parts list for any assembly that is made up of multiple parts.

Bone line – (similar to swage line, feature line or character line) – A hard, positive only, linear peak in the body of a vehicle that even though it is not a structural feature, can impact the performance of a vehicle.

Boss – A boss is a piece of material that protrudes from the surface of the work space and is used to precisely locate another part so that they operate together correctly.

Bottleneck – A bottleneck is the slowest station in the assembly process that determines the overall production rate.

B-Pillar – Pillar next to the front seat occupants’ heads

Broken Edge – Broken edge describes a condition where the edge of a sheet of metal contains cracks or splits and is generally uneven.

Burnishing – A machining process that polishes a material down until the surface is smooth and shiny in appearance.

Burr – A rough edge on a part that is a by-product of the machined part.  Sometimes called a sliver or a chip, burrs are usually sharp and undesirable.

Bushing – A hollow, cylindrical, metal sleeve that helps to prevent abrasion for metal parts and works as a guide within the automobile for valve rods and other critical components. Unlike a bearing a bushing only is one single piece of metal that uses the frictional properties of the material to provide durability support.

Cabin – The interior portion of the vehicle where the driver and passengers sit.

CAD (Computer Aided Design) – The use of a computer and specialized software to design, modify, simulate and analyze the design of a vehicle and its subcomponents.

CAM (Computer Aided Manufacturing) – The use of specially configured computers that monitor manufacturing process automation and can make adjustments to avoid bottlenecks and optimize production throughput times.

Camber–A convex curve in a structure or design. For vehicles this also means where the vehicle’s wheels are slightly more slanted at the bottom than the top to make the vehicle easier to steer.

Car Recall – A car recall is performed by an automotive manufacturer when a quality defect has been identified that must be corrected because there is a chance that a passenger’s safety could be impacted. When a car recall occurs the automotive manufacturer assumes all cost for the repair and/or replacement of the flawed part.

Casting – Casting uses molds to make solid objects from glass, plastic or metals where the material is heated until it’s in liquid form then allowed to cool until it hardens into the shape of the mold.

Cell – A part cell or a manufacturing cell is a station in the manufacturing assembly process line where a specified assembly, test or other function is performed. It refers to the group of machine as a whole.

Chamfer – A chamfer is formed by beveling a sharp edge such as a corner typically at a 45 degree angle.

Change ManagementA process to coordinate change to a design or production process where all areas of the change are evaluated and a comprehensive plan put in place to implement the change to avoid quality defects.

Changeover (tooling/die)–Tooling or die changeover in manufacturing is when these pieces are removed from manufacturing equipment so a different part can be produced. Tooling or die are specific to a specific product.

Chassis – The framework within the vehicle that supports all the components that go into the vehicle.

Clay – Clay modeling is used to build early versions of prototype vehicles to allow designers to assess the overall build of a vehicle.

Clutch – Mechanical device in manual transmission vehicles that disengages the power transmission from the drive shaft and allows the driver to switch gears.

CNC (Computer Numerical Control) –Computer numerical control is used in programming a process to complete specifically designed instructions and commands during manufacturing.

Coasting (vs Driving) – When a driver allows a vehicle to move forward using the momentum it has built up from driving. The engine only uses enough fuel to run but now additional to move forward and the transmission will continue to turn but no additional power is being applied. This creates a force on all the gears in the drivetrain in a similar fashion as the reverse gear.

Compilation Drawing – A compilation drawing combines multiple levels of detail of a design into one top level drawing to model how a top level assembly will be built and is used to review the fit of the parts as a whole.

Component – A component is a raw material or part of an assembly that is used to assemble a vehicle.

Concept Car – Prototype version of a car that is built with new features or materials that allows the design to be tested out during the development phase to verify feasibility of the new features. Concept cars rarely will make it to production but are valuable development tools engineers use in the design process.

COQ (Cost of Quality)–Cost of Quality describes the costs a company incurs to maintaining acceptable quality levels for a product. Included in the cost is the cost of failure or when quality levels fall below acceptable levels.

Corrective action – A corrective action is the formal name for an action taken to correct a design or production process issue that could cause a failure in the field or produce a poor quality product. Corrective actions are documented with clear steps and timelines to contain and correct the problem.

Corrosion – Corrosion is the process where materials are destroyed by a chemical reaction. Example: oxides and salt in the environment reacting with the metals on a vehicle cause rust, a type of corrosion.

Countersink–Countersink is when an edge is created at the lip of a hole to allow the screw to be flush to the surface.

Cowl – The term for the base of the windshield on a vehicle.

Cp (Process Capability)–Process capability is the statistical measurement used to determine if a production process is capable and sustainable. Process capability is expressed as a capability index Cpk or Cpm or a process performance index.

C-Pillar – Located in the rear portion of the vehicle before the trunk

Cpk– Cpk or Process capability index or sometimes calledPpk, process performance index are the calculations that predict how many parts will be produced out of specification when a production process is running. Cpk is used for a sample statistics while Ppk is used for a population.

Crease line – Lateral lines which travel down the main body section of the vehicle.

Critical Feature –A critical feature on a part or drawing describes a feature that without which the part will not function as designed.

Customer Quality Engineer CQE – Customer quality engineers manage the outgoing quality issues that occur with a customer. These may involve PPAP’s or other issues that the customer is looking for. They usually work with the supplier quality engineers for the customer, for example: Customer quality engineers at a Tier II supplier will work with supplier quality engineers at a Tier I.

Customer–A customer is a person or a company that purchases a product or service.

CVT (Continuously Variable Transmission) – Automatic transmission system where the transmission ratios are constantly adjusted to provide the best performance and fuel economy

Cycle time – The time required to complete a specified activity or process; for example – final assembly test requires twenty minutes to complete.

Cylinder configuration –Cylinder configuration in an automobile describes the location and orientation of the pistons within the engine. Vertical configuration (V6, V4, V8) has equal amounts of cylinders on each side of the engine block forming a V shape. Flat configuration has the cylinders (Flat 6) in a row forming a straight line in the engine block.

Datum – The correct term for a single datum, data is commonly used to represent both singular and plural versions. In drafting and design, datum is a numerical or geometric value that references other values within a drawing. In engineering GD&T, a datum references a point from which angles, heights or distances are measured from.

Deburr – Deburr is a machining process that removes the rough edges or ‘burrs’ from a machined part.

Deck – The horizontal surface of typically the back of the vehicle or the trunk lid.

Defect–A defect in the automotive industry is a fault or imperfection in the design or as a result of the production process.

Design for Manufacturability (DFM)– The process where automotive design engineers design parts that can be easily manufactured without requiring specialty equipment.

Design of Experiments (DOE) –Design of experiments or DOE is when an engineering and quality team designs an information gathering experiment to gather information, solve a quality issue or try a new design idea to validate an idea or identify root cause of a quality issue.

Deviations –A temporary change in the design tolerances for production. A deviation is used when incoming material is not meeting all the required specifications.

DFMEA (Design Failure Modes Effects Analysis) – The design FMEADesign failure mode effects and analysis looks at the potential failure modes, their severity and chance of occurrence in the design of an automotive product. These modes are ranked and preventative actions taken to improve the quality of the design.

Die (tooling) – A die is a tool used in the manufacturing process that is used to cut a material using a mechanical press of some sort.

DIN (DeutschesInstitutfürNormung) –The DeutschesInstitutfürNormungis the German Standards organization that is their branch of ISO which manages the standards for a majority of the technologies in the country.

Drag (aerodynamic) – The atmospheric resistance to forward movement

Drilling – A machining process that uses a rotating head in a variety of shapes and sizes to cut a hole in a part.

Drivability – Drivability is the smoothness and steadiness of a vehicle when it is being driven on the road. Drivability takes into account how the vehicle accelerates, brakes and handles.

Drivetrain– The components of a vehicle that produce power and deliver it to the surface of the road. This includes the engine, transmission and other components that assist in transferring power.

Driving (vs Coasting) – Fuel is consumed by the engine and the force generated is applied to the transmission which propels the vehicle forward. Cars are designed to withstand more torque when in drive mode than in coast mode.

DSG SMG (Direct Shift/Sequential Manual Gearbox)–Electronically controlled, dual clutch multiple-shaft manual gearbox that is a type of semi-automatic transmission which is known for providing faster shift times than conventional automatic transmissions.

Dual Clutch Transmission – A semi-automatic transmission that uses two separate clutches for odd and even gears that will operate as an automatic transmission during normal driving but gives the driver the option to manually shift gears.

Durability – The ability of a material to resist decay, wear and tear during it’s useful life.

ECM deburring (Electro-Chemical deburring)– Electro-Chemical (ECM) is the process of removing burrs, or machining defects, from a metal using electrochemical processes on electrically conductive materials using a process that is the reverse of electroplating.

ECR/ECO(Engineering Change Request, Engineering Change Order) – Engineering change request is the form that initiates the change process. A cross-functional team then assesses the change and what will be required before initiating and engineering change order to the team to put the change in place.

Electric Vehicle (EV) – An electric vehicle is a vehicle that uses electric motors as the primary source of propulsion.

Engine Displacement – The volume that is displaced from all the pistons inside the engine cylinders, volume does not include the combustion chamber and is measured in both metric cc/L and English units cubic inches.

Ergonomics (customer) – The study of how humans interact with the vehicle or human engineering. Automotive engineers will look at the design of the cockpit and how humans will interact with all the necessary controls of the vehicle to make it as comfortable as possible for the driver and the passenger.

Ergonomics (worker) –Ergonomics is the study of workplace design and how people interact with the tools and equipment so that they work in the most efficient, safe, comfortable and productive manner to reduce the occurrence of injuries due to repetitive more or stress.

ERP (Enterprise Resource Planning) – A suite of computer software that includes numerous applications that when managed together allows all areas within the business to work together. Applications include product planning, manufacturing, inventory, shipping and billing and ERP provides an integrated view of all the processes. SAP is probably the most popular of the ERP products and is used widely in automotive.

Factor of Safety (FOS) – Factor of safety (safety factor) is the ratio of the stress required to break a material to the calculated maximum stress the material can endure without breaking during ordinary use.

FEA (Finite Element Analysis )–A method that analyzes the structural integrity of a part by breaking it down to the elemental structure to look at the discrete elements it is composed of at the atomic level.

Feasibility Study – A feasibility study is a preliminary study that is conducted to determine if a solution will work or be successful and is done prior to investing time labor and resources in a project which may not work.

Feed rate –The speed that material is fed into a process.

Fender – The area above the vehicle wheels or the portion of the body panel that starts at the front bumper and end at the first door.

Fillet (design)–A feature on a part that creates an arc or radius between two flat features. Used to smooth edges, add strength, or to complete a transition in a part. A typical fillet is given a radius and then is tangent to the sections.

Firewall/ bulkhead – The firewall is located between the engine compartment and the passenger compartment and helps to prevent fire from entering the cabin.

First Pass Percentage – First pass percentage refers to the percentage of products produced that pass all inspection screens and final acceptance tests on the first try.

Fixture – A fixture is a specially designed piece of tooling that assists in the manufacturing process that performs a special function such as press fit a terminal on a wire, check length or hold a component for assembly.

FMEA (Failure Mode Effects Analysis)Failure Mode Effects Analysis or FMEA is a failure analysis technique used by automotive engineers to look at potential areas where failures can occur in both the product design and production and provides a system to assess the impact, severity and occurrence so that preventive actions can be taken. FMEAs are conducted on product designs, production processes and product performance and capabilities.

Forging – The manufacturing process where metal is heated till it softens and then is formed into specific objects by hammering.

FWD (Front Wheel Drive)– Front wheel drive vehicles are where power is primarily applied to the front wheels for propulsion.

Gantt chart – A Gantt chart is a type of bar chart that is used as a scheduling tool to manage the development timelines for projects. The Gantt chart will show scheduled, completed and in progress work or a given time period and show task dependencies and other relationships so that the project manager can manage the project successfully.

GD&T (Geometrical Dimensioning and Tolerances)GD&TThe system for designing and defining geometrical dimensions, characteristics and tolerances using a standard symbolic language

Gear cutting–Gear cutting uses a variety of processes such as milling, broaching and abrasive waterjet cutting to create the part.

Gill – Vent located on the side of the vehicle near the fender that is sometime used for hot air outlet by primarily is decorative in today’s designs.

Go/ No-Go gauge – A Go gauge that is designed so that when a part fits, that means it is within specification tolerances but if it does not fit then it goes to rework or is scrapped. A No Go gauge is a gauge designed so that the part must not fit into it. An example is for a bearing which has an inner diameter from 1 to 1.5cm. The Go gauge will be a rod that is designed at 1mm to ensure that the ID is not too small, and the No-Go gauge will be designed just over 1.5 mm so that when it is inserted into the bearing it will not fit.

Greenhouse – Greenhouse refers to the top portion of the cabin of the body of the automobile that is primarily glass/windows.

Grinding – Grinding is a method to shape materials that are too hard or misshapen to process with conventional tools.

Hardness – Hardness is a measurement of how difficult it will be to penetrate the core of an object. In some cases there is a difference in hardness between the surface and the core (case hardened materials).

Header – The structural roof beam located above the windshield or a section of exhaust piping that is attached to the cylinder heads.

Histogram – A Histogram is a graphical display of statistical information that uses bars on a graph to represent the frequency of occurrence of data items in successive numerical intervals of equal size.

Hobbing – A machining milling process for cutting gear teeth, cutting splines, cutting sprockets.

Horsepower – Horsepower is the measurement of how much power an engine produces and how much work it can perform. As a comparison, one horsepower is the ability to lift 33,000 one foot in one minute.

ID (Inner Diameter) – The diameter measured inside of a hole within a part. Example – when the inner diameter is subtracted from the outer diameter you can determine the thickness of the wall of the part.

IP (Instrument Panel) –The instrument pane is located within the cabin of the vehicle and houses all of the electronic controls within the vehicle including the instrument cluster which houses the speedometer, odometer and other controls specific to the engine and powertrain functions.

ISO (International Organization for Standardization)–The International Organization for Standardization is the worldwide organization that provides specifications for products services and systems that ensure quality, safety and efficiency of multiple different products.

JASO(Japanese Automotive Standards Organization)–The Japanese Automotive Standards Organization is part of the Japan Society of Automotive Engineers and is responsible for developing and maintaining standards used by the automotive industry in Japan.

Just in Time Manufacturing (JIT) –- Just in time manufacturing is a manufacturing philosophy where the assembly process occurs when an order is received and the delivery due date is the same as the production and shipping times so that the component arrives ‘just in time’ to make the due date. This philosophy reduces the overhead inventory costs for manufacturing by not maintaining large amounts of components.

Kaizen–A philosophy that is used in the automotive engineering world that promotes continuous improvement and making positive changes that will increase productivity.

Kanban – A method used to control inventory in automotive manufacturing factories that was developed by the Japanese and provides just in time inventory control.

Laser cutting – Laser cutting uses a concentrated beam of light that is transmitted and focused using lenses and mirrors to cut through materials and produce the desired end product from a computer controlled plan.

Lathe – A lathe is a piece of manufacturing machinery that machines round stock, a lathe is computer controlled and this process is also known as turning.

Lead Time – Lead time is the time required for a part to be delivered once and order is placed. Lead time takes into account the time for production, acceptance testing, packing and shipping.

Lean Manufacturing – Lean manufacturing is a production philosophy that means any time resources are used they should result in creating something of value and not be wasted.

Line balancing – Line balancing is the process of establishing the needed rate of production for a product then designing a manufacturing process that meets that needed rate. This could require building multiple stations that perform the same process to match the desired rate of production.

LSL (Lower Statistical Limit) – The lower statistical limit for a variable is the lowest value within the acceptable range for the variable. Once the variable goes below the lower statistical limit it is said to be out of control and corrective actions must be taken to bring the process and variable within acceptable.

Machining – Machining is the general term for a process of shaping, cutting or changing the physical properties of a material.

Manual Transmission – Transmission that requires the driver to manually shift the gears while driving the vehicle using a clutch.

Max Horsepower (HP) RPM–Max horsepower RPM is theRPM when the automobile operates at its max power. Below or above this RPM will decrease power. Usually specified in a specific gear as well.

Max Torque RPM – Max Torque RPM is theRPM when the automobile operates at its max torque point. Below or above this RPM will decrease torque. Usually specified in a specific gear as well.

Measurement Systems Analysis (MSA) – Measurement system analysis is a statistical process that is meant to validate a measurement tool to ensure there are no variations in the measurement processes.

Mechatronics – The combination of mechanical, computing and electronics when designing and developing a new vehicle.

Milling – A machining process that removes materials from specific areas on a part using rotary cutters and a wide range of machine tools.

Mold (or casting) – A mold is the container that molten materials are poured into to form the desired shape and allowed to harden.

MRP (Materials Resource Planning) – Materials resource planning is the function of the manufacturing planning department to ensure that sufficient quantities of raw materials are available to support manufacturing operations.

Nominal – An accepted condition or measurement which is accepted as an approximation rather than a measured exact value, a ‘nominal’ value.

Norms/ Standards – Norms and standards are informal guidelines by which business is conducted within the automotive engineering world. Norms and standards provide a basis of expectations within the organization so that each member understands their roles and what they are required to do for the team to succeed.

NVH (Noise Vibration & Harshness)–NVH is one of the biggest challenges in the automotive engineering design. Automotive engineers work to eliminate exterior noise and create a peaceful environment within the vehicle additionally they work to create a smooth ride, free from vibration and harshness.

OBD (On Board Diagnostics) –The self-diagnostic reporting capability found on all vehicles produced in the 1990s-present times. The OBD system will provide status of the vehicles components and error codes that will help to trouble shoot problems with the vehicle. The diagnostics codes provide more detailed information than the “idiot lights” that illuminate when there is a problem.

OD (Outer Diameter) – The outer diameter of the part is the diameter as measured to the outermost surface of a circle.

OEE (Operation Equipment Effectiveness [or efficiency]) – Operation equipment effectiveness is a calculation based on three important factors including availability, performance and quality of the equipment used in manufacturing.

OEM(Original Equipment Manufacturers) – Original Equipment Manufacturers or OEMs in the automotive industry are the companies that manufacture the vehicles using the components and subassemblies that Tier I supplier provide to them.

OSHA (Occupational Safety and Health Administration) – OSHA is the government agency responsible for overseeing all aspects of the work environment to ensure it is safe, healthy and that all workers are giving training, education and assistance for their jobs.

Overhang – The portion of the vehicle that lies in front (A) of the center point of the wheel or for the rear of the car lies behind (B) the center of the wheel.

Oversteer– Oversteering occurs when a driver is turning a vehicle and the vehicle turns more sharply than the driver intended.

Pareto analysis – A pareto analysis is a formal quality technique using a bar graph that looks at all the reported problems and helps identify which problem is most severe and should be addressed first so that the maximum benefits will be provided by addressing that issue first.

PFMEA (Process Failure Modes Effect Analysis) – PFMEA is a analytical technique used by process engineers to look at potential causes of failure in a production process, the severity of the failures and the whether or not the failure can be detected and uses rankings for each of these measurements to identify the highest risk areas and puts controls in place to correct or monitor these potential failure modes.

Pillar – Structural components found within the body of the vehicle.

Pitch (rotational direction)–Rotation around a lateral axis within a vehicle that changes the vertical direction of the front or rear of a vehicle.

Pitch (thread)–Pitch is the distance between two threads on a screw or bolt or the distance between the tooth on a gear.

Plenum – The base of the windshield of the vehicle where the windshield wipers are located or the location of the intake manifold.

Poke Yoke – An error proofing method used in manufacturing that helps to eliminate mistakes and remove variability in products by forcing the operator to only perform an action one way. Poke Yoke designs ensure that the part is always correct by making sure that incorrect parts will not fit to reduce the chance of quality problems.

Powertrain – The components of a vehicle that produce power and deliver it to the surface of the road. This includes the engine, transmission and other components that assist in transferring power.

PPAP(Production Part Approval Process)– The PPAP process (Pronounced pee-pap) is the process by which suppliers qualify a raw material, component or end process to make sure there are no safety, design or quality issues and that the manufacturer can produce the part without quality issues.

Ppk– Process performance index are the calculations that predict how many parts will be produced out of specification when a production process is running. Cpk is used for a sample statistics while Ppk is used for a population.

Pre- Series – Pre-series automobiles are vehicles produced that help test out the production processes and ensure that everything is prepared for start of production.

Preload – Preloading is when a portion of the load a part is designed to bear is applied and then the part is tightened or adjusted so that it is prepared to bear the full load it was designed for.

Preventative Maintenance – Preventative maintenance is routine maintenance done to keep manufacturing equipment and machinery in optimal running condition and to avoid downtime due to breakdowns or repairs being needed.

Product Development Cycle – The defined steps within an automotive company to develop a product from the initial concept phases through design and development all the way to production.

Pull System (manufacturing) –A pull system in automotive manufacturing is when inventory is produced when it is needed and there is an order available.

Punching – A machining process that puts holes in a part using a die and punch tooling.

Push System (Manufacturing) – A push manufacturing system produces large amounts of product and forces them upstream in the process whether they are ready for them or not. Push systems result in large amounts of unsold inventory sitting around.

Quarter panel – Describes the metal components in the front or rear corner of the automobile.

Radial – Radial describes forces or directions that move out from a common center.

Rake– The angle between the vehicle and the horizontal axis of the ground, if the back is higher than the front it is a positive rake or if the front is higher it is a negative rake.

Rapid Prototyping – The process where representative models of a part are built that will be dimensionally correct but not functional to assist with the development process. Rapid prototyping or ‘quick turn’ prototypes are built as demonstration models or placeholders to assess fit.

Redline –The process where a drawing is marked up with changes that must be made to a design, the process is called ‘redlining’ as typically a red colored pen is used so that all the changes can be easily seen.

Rocker (rocker panel) – The metal portion on the body of the vehicle between the doorsills and the passenger compartment.

Rockwell Standard Hardness Testing – A test to determine how hard the surface of a material is using a scale from A to G with G being the hardest.

Roll–Steering effect that occurs when load within the vehicle transfers from side to side allowing the axles to move from their normal parallel relationship.

Root Cause Analysis–Root cause analysis is a problem solving method that looks for the root cause of quality or design issues with a process. The root cause of an issues is the one cause that will permanently correct an issue when it is fixed or removed and its removal stops recurrence of the issue.

Roughness/Surface Finish – The measurement of the amount of vertical deviations in the surface of a texture, small deviations mean the surface is smooth, large means the surface is rough.

RP (Rust Preventative) – A material, usually liquid that inhibits rust on a part. An example is an oil coating that prevents parts from being exposed to direct humid air.

RPM (Revolution per Minute)– Engine RPM represents the revolutions per minute for the engine crankshaft.

Run at Rate (R@R) – A trial production run, usually in the late prototype stages of an assembly process, where the assembly or production is tested at the serial production takt time/speed for a limited trial. The goal of run at rate is to see what problems occur while running the process at the speed it will run in serial production. R@R usually uncovers ergonomic or logistical issues in the process and allows these to be fixed prior to serial production.

RWD (Rear Wheel Drive) – Rear wheel drive vehicles apply power to the rear wheels primarily for propulsion.

SAE (Society of Automotive Engineers)–The Society of Automotive Engineers or SAE is an international group of engineers and technical experts from the automotive and aerospace industries that collaborate to develop standards with their fields, provide training and support many charitable programs for aspiring engineers.

SAP (Systems, Applications, Products) – A company that creates Engineering Resources Programs that for businesses. There are many companies that do this but SAP is by far the largest. When someone refers to SAP they are usually referring to the software itself that is used in most manufacturing facilities to organize and manage resources. See ERP for more details.

Scoop – An opening or a surface that is intended to direct airflow in a specific direction to assist or improve vehicle propulsion.

Series Production – Series production or batch production is the manufacture of a product in a series or group of operations that ensures each product goes through each operation.

Setup time – The time required to set up tooling and fixturing, bring up customized programming and load materials to changeover a manufacturing process.

Shift Quality – A subjective assessment for how the transmission of an automobile moves from gear to gear. Shift quality is used to assess drivability and overall experience with the automobile.

Shoulder line–The line on an automobile that is formed where the top and side surfaces extending from the hood to the quarter panel shoulder.

Shut line – The line that is formed between a car door and the body of the vehicle when the door is closed.

Six line – A line that extends from the C-pillar to the rear wheel well.

Six SigmaSix Sigma is a quality process that was developed by Motorola in the 80s to improve manufacturing quality and provide a method for quality monitoring and control. The six sigma goal for manufacturing is to drive quality to less than 4 defects per million parts built.

SPC (Statistical Process Control)Statistical process control is the method of using statistical control charts and calculations to analyze a process to keep it within statistical control and maintain process capability.

SPC (Special Part Characteristic)– An item on a drawing or in an automotive design that is determined to be critical to the form, fit or function of the end product or function critical.

Stamping – Stamping is a material process that uses a formed die or stamp and then sandwiches a material within the die changing its form.

Standard Deviation – A measure of the dispersion of a group of values and is calculated by determining the square root of the mean of the differences of the squares of the values in the group.

Standardized Work Instructions (SWI) – Standardized work instructions are used in automotive engineering manufacturing processes to ensure that all processes are consistent, timely and repeatable no matter which operator is performing the process.

Start of Production SOP– Start of production describes the point where the product has completed the development and validation processes and is ready to start mass production. Once a product reaches start of production it will typically begin to ramp up where production starts at slow volumes

Statistical Distribution Graph – A statistical distribution graph is a graphical representation of observed or occurring values that show their frequency of occurrence.

Strake – A crease in the sheet metal body that is styling feature for sports or high performance vehicles.

Supplier – A supplier is anyone who sells materials or components to a company, suppliers are classified as Tier I, Tier II, Tier III depending on whether they sell raw materials or assembled components who they supply.

Supplier Quality Engineer (SQE)–Supplier quality engineers manage the internal quality and incoming quality from suppliers. They manage day to day monitoring of quality levels, manage quality issues and coordinate PPAPs, audits and root cause analysis while working with design and production to develop high quality products and production processes.

Supply Chain Management (SCM) – Supply chain management coordinates the movement of raw materials, components and in process materials from the beginning of the assembly process until they are shipped to the end customer.

Surface Hardness/Surface Hardness Depth – Surface hardness is a measurement of how difficult it is to penetrate the surface of an object and the surface hardness depth is how far this extends into the material.

Suspension – The springs, shocks and related parts between the wheels and the frame of the vehicle that support the frame and help to reduce shock and vibration from the road.

Takt Time – Takt time comes from the German word Taktzeit which translates as ‘meter’ and is the process for setting the pace for a manufacturing assembly line to match the production demand rate.

Tangential – A stress or direction that is applied at 90 degrees to the radius of the object.

Tapping – A machining process that creates threads inside a hole in metal, plastic or wood to all a screw to be twisted in.

The Big Three – The Big Three refers to the top three automotive manufacturers in the United States and Canada which are General Motors, Ford and Chrysler.

Threading – A machining process that creates a multispindle effect inside a hole in metal, plastic or wood to all a screw to be twisted in.

Tier I Supplier – Tier I suppliers provide final equipment directly to the automotive manufacturers or OEMS. Tier I suppliers will supply major subassemblies such as the assembled dashboard or a full drivetrain so that it can be installed into the vehicle.

Tier II Supplier – A tier II supplier will provide components and materials to a tier I supplier.

Tier III Supplier – Tier III suppliers typically supply raw materials that are used to fabricate and produce components.

Tolerance – The allowable variation in a machined or manufactured part, for example a cut wire will be 120mm +/- 10 mm means the wire can measure 110 – 130 mm in length and still be accepted.

Tooling – Tooling is custom designed implements that perform a specific job during the assembly process.

Torque– Torque describes the twisting force that passes through the drive train of an automobile initiating motion. The engine powers the drive train which is measured in ft. lbs. of force, higher torque is required to overcome resistance to motion such as when a vehicle first begins moving.

TQM (Total Quality Management)– The TQM process is a holistic quality approach that uses an integrated quality process of continuous improvement for an automotive organization. The goal of TQM is to incorporate progressive changes to gradually transform an organization with changes in the attitudes, practices, structures and systems.

TS 16949TS16949:2009 is the document that defines the quality management systems and requirements for all products within the automotive engineering and manufacturing world. In order to develop and produce a product in the automotive world companies must demonstrate to auditors that they meet the requirements for TS 16949 to receive certification.

Tumbling – A type of deburring process that places the part inside a container of finishing pieces and then the container is rotated.

Turn under – The shape of the rocker panel of the vehicle as it curves inward at the lower edge.

Turning – Turning is when a material is held between two plates and then the cutting tool is rotated to form the desired shape.   There are variations on turning including: step turning, chamfering, facing, roughing or finishing.

U-Joints (Universal Joints)– Flexible, double pivoted joint that allows power to be delivered through two shafts at an angle to each other and delivers power to the wheels.

Understeer – Understeering occurs when the vehicle turns less sharply than would be indicated by the motion of the steering wheel.

USL (Upper Statistical Limit) – The upper statistical limit for a variable is the highest value within the acceptable range for the variable. Once the variable exceeds the upper statistical limit it is said to be out of control.

Valves – Valves are located within the crankcase ventilation system of the engine and routes blowby from the crankcase to the intake manifold and then back to the engine as part of the fuel-air mixture and helps to cut emissions and improve fuel economy.

Variance – The numerical value that shows the largest difference in the range of values within a group.

VIN (Vehicle Identification Number)– A vehicle identification number is a coded series of numbers and letters that is used to identify motor vehicles, trailers, motorcycles and mopeds and is defined and controlled by the International Organization for Standardization (ISO) specification number 3833.

Waste (quality term) – Waste in a manufacturing process is material or processes that do not result in production of something of value that can be sold to a customer.

Wheel arch – The opening in the side of the vehicle that allows access to the wheel.

Wheelbase – The wheelbase of a vehicle is the distance between the center of the front and the rear wheels.

Wire EDM – Wire electric discharge machining is a process that uses electrical sparks to shape a piece of metal by electric discharge across two electrodes.

X bar – The numerical average of a data set is call X-bar and is calculated by adding all values and then dividing by the total number of values.

Yaw–Rotation around a vertical axis that passes through the car’s center of gravity.

Comments 8

    1. Post

      Thanks, These terms come up all the time and it is important that students understand the terminology. To teach automotive engineering, you need to be able to talk the talk. What type of teaching do you do?

  1. Sanford Swain

    This is most informative!! Thankyou.! Can you please print and article with TERMS FOR VARIOUS TYPES OF QUALITY DEFECT IN THE AUTOMOTIVE INDUSTRY… Like burrs, pits, appearanced.. Non conformed conditions… I have to relay to suppliers defects and sometimes I don’t have the technical words to describe what I’m seeing.. Thankyou.

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