An original equipment manufacturer, commonly shortened to OEM, is a company responsible for a product, system, machine, or piece of equipment that is produced to its design, specifications, performance requirements, or brand. The OEM may manufacture some parts internally while purchasing many other components and production services from specialized suppliers.
Because modern products often contain parts made through many different manufacturing processes, OEM production frequently depends on a network of machining companies, fabricators, molders, casting companies, component manufacturers, electronics suppliers, assemblers, finishers, and contract manufacturers.
OEM Manufacturing Defined
OEM manufacturing is the production of products, assemblies, or components according to requirements established by an original equipment manufacturer, often using a combination of internal production and specialized outside suppliers.
The term does not necessarily mean that the OEM physically manufactures every component itself. In many industries, the OEM is responsible for engineering, product specifications, system design, qualification, final assembly, branding, distribution, or some combination of those functions.
Individual parts may be produced by suppliers that specialize in a particular material or process. A machined housing, stamped bracket, molded plastic cover, spring, seal, bearing, electrical connector, or gear may all come from different manufacturers before being assembled into the final product.
How OEM Manufacturing Works
Although every product and industry is different, OEM manufacturing generally moves through a sequence that connects engineering requirements with sourcing and production.
Functional requirements, dimensions, performance expectations, operating environment, materials, cost targets, and production volume are established.
Drawings, models, tolerances, materials, interfaces, finishes, assembly requirements, and testing criteria are developed.
Appropriate manufacturing methods are selected based on material, geometry, tolerance, volume, tooling, lead time, and cost.
Qualified suppliers are identified for machining, molding, stamping, fabrication, castings, purchased components, finishing, or assembly.
Initial parts or assemblies are produced and evaluated for fit, function, dimensional accuracy, material performance, and manufacturability.
Approved components move into controlled production with established tooling, process parameters, inspection methods, and delivery schedules.
Parts are inspected, documented, assembled, tested, packaged, and prepared for integration or shipment.
OEMs Often Depend on Specialized Manufacturing Suppliers
The complexity of manufacturing makes it impractical for many OEMs to perform every process internally. A company that designs industrial machinery, for example, may require CNC-machined shafts, fabricated frames, electrical enclosures, bearings, springs, fasteners, motors, seals, and electronic components.
Instead of maintaining every possible manufacturing capability, OEMs can work with suppliers that already specialize in those processes or component categories. This allows the OEM to match each part with the production method, equipment, material knowledge, and quality capabilities required for that component.
Some suppliers provide only a single manufacturing process. Others offer broader services that may include engineering assistance, material sourcing, machining, fabrication, finishing, assembly, inspection, packaging, and production management.
What Are OEM Components?
OEM components are parts incorporated into a larger product, machine, assembly, or system. Some are custom-designed for one product while others are standardized industrial components selected to meet the required performance and dimensional specifications.
Fasteners & Hardware
Screws, bolts, nuts, washers, hinges, latches, locks, pins, clips, and other joining or mounting components.
Bearings & Gears
Bearings, gears, shafts, couplings, ball screws, linear motion components, and related mechanical drive parts.
Valves, Pumps & Seals
Valves, pumps, fittings, O-rings, gaskets, hydraulic seals, pneumatic components, and fluid-handling parts.
Electrical Components
Motors, transformers, coils, connectors, switches, sensors, enclosures, power supplies, and related electrical hardware.
The selection of an OEM component typically considers operating load, environment, material compatibility, dimensions, expected service life, maintenance requirements, cost, and availability.
OEM Manufacturing vs. Contract Manufacturing
OEM manufacturing and contract manufacturing are closely connected but describe different roles. The OEM generally owns or controls the product requirements, while the contract manufacturer performs agreed production work on the OEM's behalf.
| Area | OEM | Contract Manufacturer |
|---|---|---|
| Product Responsibility | Typically controls the product definition, requirements, brand, and market. | Produces parts, assemblies, or finished goods to agreed requirements. |
| Engineering | May create the complete design or retain control over critical specifications. | May provide design-for-manufacturability, process engineering, tooling, and production support. |
| Production | May manufacture internally, outsource production, or use a combination. | Performs contracted manufacturing operations or manages a defined production scope. |
| Supply Chain | May directly manage component suppliers and purchasing. | May source materials and components when included in the manufacturing agreement. |
| Quality | Establishes product requirements and supplier expectations. | Controls manufacturing processes and inspection within the contracted scope. |
Our separate OEM vs. contract manufacturing guide examines these responsibilities in greater detail.
Common Manufacturing Processes Used for OEM Production
OEM products may combine dozens or hundreds of individual parts, and those parts can require very different manufacturing processes.
CNC Machining
CNC machining removes material from metal, plastic, and other workpieces to produce precise components. Milling, turning, Swiss machining, drilling, grinding, and electrical discharge machining may be used for shafts, housings, fittings, fixtures, blocks, connectors, and other precision parts.
Metal Fabrication
Fabrication combines processes such as cutting, bending, forming, welding, punching, and assembly to produce frames, brackets, panels, cabinets, guards, structural components, and equipment housings.
Metal Stamping
Stamping uses presses and tooling to cut or form sheet metal into parts such as brackets, clips, terminals, washers, contacts, covers, and structural components. Progressive dies may combine multiple operations for higher-volume production.
Casting & Forging
Casting creates components by introducing material into a mold, while forging shapes metal through controlled force. These methods are commonly considered when geometry, strength, material characteristics, production quantity, and machining requirements make them appropriate.
Plastic Manufacturing
Injection molding, extrusion, thermoforming, blow molding, rotational molding, and plastic fabrication can produce housings, covers, tubing, profiles, containers, insulators, clips, bushings, and numerous other OEM components.
Process and Component Research
The ANONMGUR resource network also references specialized manufacturing information covering processes and component categories used throughout OEM production.
Quality and Inspection in OEM Manufacturing
A supplier must do more than simply make a part that resembles the drawing. Production components need to repeatedly meet the dimensions, materials, finishes, mechanical properties, functional requirements, and documentation specified by the OEM.
Quality planning can involve dimensional inspection, gauges, calibration, material certification, process control, first article inspection, functional testing, traceability, sampling plans, statistical methods, optical inspection, and other verification methods depending on the part.
Tighter tolerances can increase process difficulty and inspection requirements, so tolerances should generally reflect what is actually necessary for fit, function, interchangeability, assembly, and product performance.
What OEMs Consider When Selecting Manufacturing Suppliers
Supplier selection is rarely based on price alone. The manufacturer must be capable of producing the required part consistently and supporting the expected production program.
These factors become particularly important when a supplier produces a custom component that cannot easily be replaced without new tooling, validation, qualification, or production testing.
OEM Manufacturing Is a Network, Not a Single Process
Most OEM products are the result of multiple manufacturing processes, specialized component suppliers, material decisions, quality requirements, and production relationships working together. The OEM defines or controls the product requirements while suppliers contribute the specialized processes and components needed to turn those requirements into repeatable production.