These custom 4140 flat socket head screws were produced domestically for our aerospace customer using AISI 4140 alloy steel material per AMS 6349. Heat treat to 160-180 ksi per AMS 2759 was performed to finalize the production process. Magnetic particle inspection per ASTM 1444 (Type I, Meth A, Sens Lev 3) was performed after the machining process was completed. Lead time for this part varies significantly based on how busy the manufacturing and testing facilities are at the time of start.
The hex socket drive was cold headed and the head angle was to be between 80 and 84 degrees. 1/4-28 thread length (per AS8879) was set to .395-.415 inch and the head height was not to exceed .164″. Total of 150 pieces were produced for the pictured order.