They're built from 4130 chromoly that goes through a heat treated process to strengthen them

WEIGHT: 601g / 21

Material: full CNC 6061-T6 alloy refined hub-shell

WEIGHT: 190g / 6

Its chromoly construction ensures that the spindle is built to last

S&M Drain Man Sprocket Size:25t They're built from 4130 chromolyMade in the USA, the S&M Drain Man Sprocket is one tough part able to take some serious abuse. Its solid 6061 aluminium construcion is 3D CNC machined to give it its clean cutout design, which reduces the weight of the sprocket. It features machined 1 8" offset teeth for improved chain alignment. The S&M Drain Man Sprocket fits to 19mm, 22mm and 24mm crank spindles with 48 splines with the included adapter ring. ###section### Product Specs TYPE: Bolt