10.9 Hexagon Trimmer Sems P-2 Black Oxide Film

This product uses SCM hex bolts and 40 - 50 HRC spring washers.
Spring washers/round washers with embedded metal and S55C circular washer
These washer insert sizes are designed to prevent forgotten washer insertion and for reducing the time and effort required to insert them. They are also used for inserting into conventional iron washers. The inner diameter is therefore smaller than the nominal diameter.
This new product is ideal for use in parts which lack strength.