Custom Tapered Shoulder Socket Head Bolts

 

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".  

Custom Stainless Steel Socket Shoulder Bolts

 

These custom stainless steel socket shoulder bolts were manufactured using 18-8 stainless steel material with factory passivation finish.  The head was fully cold formed, which took multiple tooling iterations to get just right.  1/4-20 2A thread was rolled at a length of .575" underneath the .305-.311" diameter shoulder.  A .190" across the flats hex socket drive was incorporated at a depth of .120" min.  Certs were made available to our customer's specifications.

Custom Shoulder Bolts For Gun Manufacturer - .185 X .500 Black Oxide

 

We had approximately 120,000 pieces of these custom shoulder bolts manufactured domestically in the USA for our gun manufacturing customer.  The shoulder measured .185 X 1/2 and 8-32 thread was rolled.  To save on cost we incorporated a convex relief underneath the head in leu of a machined relief, allowing us to complete the entire head portion with cold heading.  The shoulder was centerless ground to a +/-.001 diameter tolerance and we also made sure to meet the .127/.125 across flats requirement on the 1/8 hex socket drive, which was a critical feature for optimal key engagement.  Full certs were provided with the parts.