The three grades, in plain terms
Genuine means the part is manufactured or supplied under the original equipment brand, in original packaging, carrying that brand's part number. It is the part the machine was built with, bought from the channel that owns the name.
OEM-quality means the part is made to the original specification, frequently by a manufacturer at the same tier as the original supplier, but it is not branded by the machine builder. In practice this is where the most interesting buying decisions live, because the same factory that supplies an assembly line often sells the same item unbranded elsewhere.
Aftermarket means a third-party specification. Quality within this category varies more than the other two combined: some aftermarket lines are excellent and some are not fit to install. That is precisely why naming the maker matters more than naming the grade.
Why the grade conversation is usually about consequences, not price
The reason a grade question is difficult is not that buyers cannot compare prices. It is that the consequences of a failure are not the same in every application, and the price difference does not scale with them.
A failed travel motor on a machine working a single shift on a farm is an inconvenience. The same failure on a machine holding a production line open is a contractual problem. A failed injector in a fleet with five spare units is a workshop task; in a one-machine operation it is a stopped job. The part costs roughly the same in each case; the cost of the part failing does not.
So the useful question is not which grade is better. It is what happens to your operation if this specific component stops working, and how much warning you would get. Components that fail without warning, on machines that cannot be idle, are where the higher grades earn their price.
A practical way to decide
Work through three questions. First, is this a safety-related or structurally loaded component? Brakes, lifting hardware and load-bearing castings belong at the top of the range without much debate. Second, will the part be inspected or warranted by a third party? Some insurance and rental arrangements require documented genuine parts on certain repairs. Third, how long will this machine stay in the fleet? A part that has to outlive the machine does not need to be genuine, and a part that has to outlive three more owners does.
Everything else is a normal buying decision, and the honest answer is that on most repair jobs more than one grade is defensible. What is not defensible is discovering the grade after the part has been installed.
How we quote, and what we will not do
Guangzhou Shenyue Machinery Technology Co., Ltd. has supplied excavator parts from Guangzhou since 2007. We are an independent supplier and we hold formal authorization for five brands: Garrett, Mitsubishi Heavy Industries, TONGMYUNG, NIKURA and Marusan. For Kobelco and the other machine brands we are not an authorized dealer. We supply those as genuine parts bought through original supply channels, or as OEM-quality and aftermarket equivalents, and we state which one on every line of a quotation.
Two things follow from that. First, we will not describe an aftermarket part as genuine, even when the aftermarket part is good. Second, we will tell you when the cheaper option is the sensible one, because a buyer who feels oversold on one line does not come back for the next four.
Frequently asked
Is OEM-quality the same as genuine without the box?
Not always, and the distinction matters. An OEM-quality part is made to the original specification but not by or for the equipment brand. Often the manufacturer is at the same tier as the original supplier; sometimes it is simply a factory that holds the drawings. It is a strong category, but it is not a guarantee that the item came off the same line as the genuine part.
Can I mix grades on one repair?
Yes, and it is often the right answer. A common pattern on a hydraulic pump repair is genuine for the rotating group and OEM-quality for the seal kit and hardware. Mix the grades deliberately, on components where the consequence of failure justifies the price, rather than applying one grade to the whole job.
What should be written on the order?
The part number, the grade, the maker for aftermarket lines, the condition (new, old stock, remanufactured or used), and what the price includes. That is the record that settles any disagreement about what arrived. If your supplier will not put the grade in writing, that is itself an answer.
Send the machine model, serial number, the part numbers you have and the quantity. That is all we need to quote and confirm fitment before payment.
Request a quote