SRM specially made bolts in UK, cold dropped forged bolts, thread rolled and heat treated to high tensile condition, then chemically blacked.
These are the best head bolts on the market, you will get correct lengths so cylinder threads will not get damaged, and a superior bolt for torquing down your cylinder head.
Washers are BSA specification part number 02.0861 heavy duty, designed so they can take the torque setting without distortion.
Recommended torque setting is 30 ft lbs
