Stainless Steel Rear Axle Nut. Machined with captive washer M18 x 1.50mm Thread, 27mm Socket Size. Polished to a smooth mirror finish and highly resistant to corrosion. This makes a great replacement to rusty originals. Compliments sprocket nuts, and chain adjuster nut & bolt kits. Listed in model specific bike sections where fitment has been established. Prefer something a little more subtle? Stainless Steel is also available in black, which not only looks great but has other benefits too.. This beautiful long lasting black finish results from an application of Diamond Like Carbon Coating. (DLC) This gives supreme hardness and corrosion resistance provided by a nano composite coating, which increases the fastener lifetime dramatically and helps to prevent galling. By incorporating them right from the beginning, the overall system cost can be held level or may even be reduced. Please note that due to this special coating Black Stainless Steel is not identical to our Black Aluminium.