ACB 3645 1125 BO - 1-1/8 BO, Angular Contact Headset Bearing

ACB 3645 1125 BO - 1-1/8 Black Oxide, Angular Contact Headset Bearing Headset Bearing (30.5mm 41.8mm x 6.3mm; 36 x 45 deg) -

Angular-contact headset bearing featuring anti-corrosion Black Oxide/Magnetite coated 52100 High-Carbon Chromium alloy races paired with grade 10 Balls. Black Oxide coating provides an extra level of corrosion resistance and extended worry-free performance

This size bearing is also known in the bike Industry by these part numbers:
IS42
ACB30418K
MH-P03K

The Enduro line of headset bearings begin with chromium steel, Black Oxide finish A/C type and then offer full 440C stainless steel at the top. They are always engineered with the largest balls possible and dual lip seals riding in a micro-groove for ultimate protection against sweat and the elements. They are filled 90% with high pressure water proof grease, so you never have to guess if there is grease inside. Enduro angular Contact (A/C) bearings, all balls are engaged to spread the force over a larger surface area, pressure water and minimizing wear.

Static load - 935lbf / 4.15kN
Weight - 19g