- Genuine parts are supplied by the equipment maker or its licensee, in the maker’s packaging and with its documentation.
- OEM parts are made by the company that manufactures the part for the maker, sold without the maker’s brand.
- Alternative or pattern parts are made by other manufacturers to fit the same equipment.
- Compare quotes only within the same part type, or make the difference visible line by line.
Genuine parts
Genuine parts are supplied by the equipment maker, its authorised distributors or its licensees, usually in the maker’s packaging and with the maker’s documentation. They are often required for warranty items, and for components where class, the flag state or the maker’s service letters expect them. They are usually the most expensive option and lead times can be long for older engine types.
OEM parts
Many makers do not manufacture every component themselves. An original equipment manufacturer (OEM) makes the component for the maker. The same OEM may sell the part under its own brand, to the same drawing, without the maker’s packaging. OEM parts can offer the same quality at a lower price, but documentation and traceability should be checked with the supplier.
Alternative (pattern) parts
Alternative parts, also called pattern or non-genuine parts, are made by independent manufacturers to fit the equipment. Quality ranges from excellent to poor. Reputable alternative makers provide material certificates and dimensional checks. They are common for wear parts such as gaskets, O-rings, filters and some valve components.
Reconditioned parts
Reconditioned or overhauled parts, such as turbocharger cartridges, fuel pumps or cylinder covers, are used parts restored to specification by a workshop. They can save money and time for major components when the workshop is known and the work is documented.
How to compare quotes fairly
| Genuine | OEM | Alternative | |
|---|---|---|---|
| Source | Maker, licensee or authorised distributor | Component manufacturer | Independent manufacturer |
| Documentation | Maker’s | Manufacturer’s, check | Varies, ask for certificates |
| Typical use | Warranty, critical items | Same part, lower price | Wear parts, older equipment |
Ask every supplier to state the part type per line. A cheap total built on alternative parts is not comparable with a genuine quote unless the difference is visible. Then compare on total delivered cost, not unit price.
How Atlas Supply shows part types
In every Atlas Supply comparison, genuine, OEM and alternative parts are shown separately on each line, together with lead time and delivered cost. If your requisition says genuine only, only genuine parts are proposed. Suppliers are found in the spare parts directory by maker and equipment.
Questions
Are OEM parts the same as genuine parts?
They can be made by the same manufacturer to the same drawing, but they are sold without the equipment maker’s brand and documentation. Check traceability with the supplier.
When should we insist on genuine parts?
For items under warranty, components covered by maker service letters or class requirements, and critical components where traceability matters most.
Are alternative parts safe to use?
From reputable manufacturers with certificates, many are. Quality varies, so use known sources and keep them for appropriate items such as wear parts.