... Precision Roller Chains (A Series and B Series), Motorcycle Chains Short Pitch Precision Roller Chains (A series and B series): 2,500,000 M ... ,000 M/Year Short Pitch Precision Roller Chains (A series and B series): 1,888,811.61 M Motorcycle Chains:3,010 ... WA-A 1 6.0 Acceptable Surface Rockwell Hardness HR-45A 1 6.0 Acceptable Rockwell Hardness HR-150A 1 6.0 Acceptable Metallurgical ...