This is a Grade 5 Titanium bolt package for manual b d series transmission starter motors.
These bolts fasten the starter to the transmission/engine.
transmission to engine bolts
https://gdevelopment.us/products/k-series-bell-housing-17mm-5pk?variant=40008083210380&fbclid=PAdGRleAPqpm5leHRuA2FlbQIxMQBzcnRjBmFwcF9pZA8xMjQwMjQ1NzQyODc0MTQAAadRjAu4ZiSOH_8y-cmjPvf6Um5aSV895HpvRf29wju74ss6sNZLXDBzYYgWiw_aem_W6s1_TwbcQMHdpyTe1Zrvw