A single part number in a machinery parts catalogue can correspond to three quite different products: the original manufacturer's own part, an OEM-supplied part from the same tier-one manufacturer, and an aftermarket part produced by an independent manufacturer. All three are sold against the same reference, and all three can be supplied for the same application.

What the difference actually is

The original part is produced by the company that designed the machine. An OEM part is produced by a company that supplies that same manufacturer, using the same specification and often the same production line. An aftermarket part is produced independently, to fit the same application without being produced to the original specification.

Where the choice matters

For critical systems the grade matters most. Hydraulic components, engine internal parts and electronic control units are where a difference in specification translates directly into a difference in service life, and where an independent part is most likely to fall short of the original.

For consumables the calculation is different. Filters, seals and O-rings are specified by dimension and material rather than by tight tolerance, so a matched aftermarket part will frequently deliver equivalent service life at a lower cost. This is where the majority of cost savings in parts consumption is realistically available.

How the grade should be stated

The grade should be stated on the quotation and shown on the invoice. A supplier who supplies an aftermarket part against an order placed for a genuine part without stating this has created a problem that will surface later, at the point where the part fails.

Where a quotation records the grade supplied and any cross-reference used, the buyer can compare it against another quotation on a like-for-like basis. Where it does not, the comparison is not valid, because the two prices may be for different products.

Practical approach

For a fleet running mixed equipment, a workable approach is to specify genuine or OEM for hydraulic, engine and electronic components, and to use matched aftermarket for filters and seals where the application is not demanding. This captures most of the available saving without putting reliability at risk.

Where a machine is operating in a remote location where a failure means prolonged downtime, the original or OEM grade is usually the more economical choice even at a higher initial price, because the cost of a repeat failure far exceeds the price difference.

TOP RUN supplies both genuine and OEM parts and matched aftermarket alternatives for XCMG, Sany, Zoomlion, Shantui, LiuGong and Lovol equipment, with the grade stated on both quotation and invoice. Parts are checked against the ordered part number before packing, with over 12,500 SKUs held in Qingdao. Send the machine model, serial number or part number, and we will state which grades are available for that item.