Restorers often ask me about what was the original finish on a bike’s various metal parts. The end suffix code on the part number indicates the kind of material and how it was finished. There are duplicate finish treatments with two different codes, but I don’t know the reason behind that, to date. So, if you have questions about which is the correct fastener to order is, use this information to get it right the first time.
CODE SUFFIX 1st digit MATERIAL
0=High Carbon Steel
1=Carbon Steel
3=Brass
4=Stainless
CODE SUFFIX 2nd digit SURFACE TREATMENT
A= Zinc Plate (White)
0= Zinc Plate (White)
B= Chrome Plate
2= Chrome Plate
C= Nickel Plate
3= Nickel Plate
H= Zinc Plate (Yellow)
8= Zinc Plate (Yellow)
J= Untreated
9=Untreated
G=Black
7=Black
This research started when a question came to me about what are the differences between these 5x25mm bolts listed by part number below.
93500-05025-1H Carbon Steel, Zinc (Yellow) 93500-05025-0A High Carbon Steel, Chrome 93500-05025-0G High Carbon Steel, Black 93500-05025-4J Stainless, Untreated 93500-05025-0B High Carbon Steel, Chrome 93500-05025-0H High Carbon Steel, Zinc (Yellow)
I didn’t have the answer, at the time, but then did some research into AHMC departments and my request for information yielded the answers!
Bill Silver aka MrHonda
Comments