These custom tapered shoulder socket head bolts were manufactured using 4140 alloy steel material with 28-32 HRC hardness and zinc clear finish. The shoulder diameter tapers form 0.78" down to 0.75" and the head diameter was set to 1.00 +/-.015". Underneath the shoulder approximately .55" of 3/8-24 2A thread was rolled with thread relief allowance of roughly .085".
These custom carriage bolts were produced to our customer's drawing to class 10.9 characteristics with black oxide finish. Approximately 27MM of M10-1.5MM 6G thread was rolled underneath the square shoulder and a 3MM hole was drilled through one side of the shoulder. The square shoulder was produced to 10MM across the flats. Under the head a R45 radius was maintained to match the mating washer.
These custom grade 5 hex nuts were manufactured with both sides rounded to match the mating fitting internal radius. Production was done with cold forming process and parts were made to a 17MM across the flats dimension and an overall height of 14MM at the maximum. M10-1.5 6H thread was tapped with a standard chamfer on each side. Commercial zinc clear finish was run to complete the parts, with accompanying bake.
These custom slotted lock nuts were manufactured using 4140 alloy steel material heat treated to 28-32 HRC. A 5% taper on the shoulder was required which created some difficulties in modifying the cold heading equipment to meet the required tolerances. The outside diameter was set to 1.00" and the tapered shoulder reaches 0.75" at its minimum. Parts were run through black oxide process as the final step in the production process.