Mr Gasket - 2235G - Mr. Gasket Headlock Locking Header Bolts - M8-1.25 x 25mm - Set of 12

Headlock™ Bolts eliminate the need for lock washers, Period. That's because each Headlock™ Bolt features 24 equally-spaced, stainless steel teeth serrations that bite into and hold onto the attaching surface-eliminating the need for lock-washers.