Steel sleeve for aluminium cylinder head bolt has an external self tapping thread to secure accurately into the head

摘要

A steel sleeve for incorporating into an aluminium cylinder head has an outer self tapping thread (12) by which the sleeve is secured accurately into prepared bores through the head. The sleeve is made of cold forged steel and is provided with an octagonal inner profile (16) at one end to connect a fitting tool to drive the sleeve into the head.