Genuine parts come through the manufacturer's own channel and carry its packaging and warranty. OEM-quality parts are made to the same specification, frequently by the same tier of factory, without the manufacturer's branding. Aftermarket parts are economic alternatives whose quality varies from excellent to unusable. The right choice depends on the component: a cheap seal is a false economy, while a well-made filter or bushing is often indistinguishable in service.
The three grades in practice
| Grade | What it means in practice |
|---|---|
| Genuine | Supplied through the manufacturer's parts channel, in manufacturer packaging, with the manufacturer's part number and warranty. The reference point everything else is compared against, and usually the most expensive line on a quote. |
| OEM-quality | Built to the original specification, often by the same tier of supplier that makes the genuine part, but sold under the maker's own brand. Usually the best value on wear parts and on components where the specification is well defined. |
| Aftermarket, reputable | A known independent manufacturer's own design. Quality is variable but documented, and a good one can exceed the original on a specific weakness. Suits high-turnover items where the cost of a failure is low. |
| Unbranded | No traceable manufacturer. Occasionally fine, frequently not, and impossible to assess from the outside. The savings rarely cover one failure on a machine in production. |
How to confirm it
- Sort the list by consequence of failure
A seal that fails leaks oil. A hydraulic pump or a final drive that fails stops the machine and can destroy the components around it. Spend on the second category first, and economize on the first only where the part you are offered is traceable.
- Ask what specification the part is made to
Not what it fits — what it is made to. A supplier who can name the material, the hardness or the micron rating is describing a product. One who can only repeat the part number is reselling a box.
- Compare on cost per hour, not cost per unit
A bushing at half the price that lasts a third as long costs more, and it costs it in the workshop rather than at the parts counter. On wear items this comparison is the whole decision.
- Check what the warranty actually covers
Many aftermarket warranties cover the part and nothing it damaged. On an assembly that can take other components with it, that exclusion matters more than the price difference.
- Buy the critical seals genuine or OEM-quality, always
Liner seals, injector seals, hydraulic seal kits and final drive seals. These are low-cost items whose failure causes catastrophic downstream damage, which is precisely the profile of a part not worth economizing on.
- Keep the grade recorded on the machine file
So the next failure can be attributed. If a component fails early, the grade of the part that failed is the first question anyone will ask, and it should not require a search through old emails.
What to do about it
Where a manufacturer offers a remanufactured or exchange assembly, take it seriously. A factory remanufactured unit with a warranty often costs substantially less than new and carries far less risk than an unbranded new one.
Be wary of a quote that lists everything at one grade without explanation. Lists are priced component by component because the trade-offs differ component by component.
Where you have the time, sample a new grade on a non-critical application before adopting it across a fleet. The difference between a good aftermarket line and a poor one shows up in service, not on the invoice.
State the grade on every line of the quote you issue or accept. A grade that is not written down is a grade that will be disputed if anything goes wrong.
Need the parts this covers?
Send the machine model, serial number and the part numbers you need. We confirm fitment before payment and state the grade of every line — genuine, OEM-quality or aftermarket.
Request a quoteFrequently asked
Are genuine parts always better than aftermarket?
No. Genuine means it came through the manufacturer's channel, not that it is the best possible version of that part. For a number of wear components, a well-documented OEM-quality part made to the same specification performs identically at a materially lower cost. For critical components, genuine or OEM-quality is usually the safer choice.
What does OEM-quality actually mean?
It means the part is made to the original equipment specification, typically by a supplier at the same tier as the original. It is not the same as genuine, and a supplier who uses the two terms interchangeably is either imprecise or hoping you will not notice.
Is the cheapest aftermarket part ever the right choice?
On a low-consequence, high-turnover item where you can verify the specification, sometimes yes. On anything that can take other components with it when it fails, almost never. The saving is smaller than the risk by a wide margin.
How do I know which grade I am being quoted?
Insist that every line on the quote states its grade. A quote that lists part numbers without grades is not yet a quote; it is a list.