These custom 4140 flat socket head cap 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.