To be as transparent as possible;
As previously stated above: "The 89 WP Shafts are manufactured to the same specifications, from the same drawings, made from the same Heat Treated Steel, and finished Ground to insure concentricity as well as minimize wear on the Oil seal & bearing surfaces...just like Honda originally designed it, quality built"
The WP (Water Pump) Shafts we are offering are "like OEM", they are made by the same Japanese manufacture to the same Honda specifications including material, heat treat and final grinding dimensions as the original Honda OEM WP Shafts, hence they are ‘like OEM’.
These are not a Stainless Steel imitation that are made from non-heat treatable Stainless and not finished ground. While making WP Shafts from 300 series Stainless is considerably less expensive than using heat treated steel hardened & finished ground to a high level; the durability, wear and reliability of Stainless is very poor compared to Hardened & Ground Steel.
Honda OEM Seal wear & damage increases considerably using Stainless Shafts vs OEM heat treated Shafts due to the low hardness of Stainless (36 RC) vs Hardened Steel (62 RC). Plus; finish ground hardened steel surface finish is superior to lathe turned Stainless Steel surfaces....that's why Honda engineered WP Shafts for the 250R out of Heat Treated & Finished Ground Steel, and NOT Stainless Steel.
Since the Honda WP shafts are a discontinued item, the ‘like OEM’ WP Shafts BDT has secured are as close to OEM as we are going to get, they fit & perform the same, while maintaining Seal life equivalent to OEM.
Attached a quick Synopsis on Seal Shaft Design: