Custom slotted fillister screws we supplied to our aerospace customer at 100 pieces – ASTM A582 DFARS compliant 303 stainless steel material (Italy Melt) was used for the domestic manufacturing.  2-56 thread was incorporated at .25-.37″ in length, with the overall length underneath the head at .625 +0/-.030″.  The head height measures .070-.095″ and the slot depth is set at .033-.043″.  Head diameter was set between .145″ and .161″.  Full certs were provided with the parts per our customers usual requirements.