Custom slotted fillister screws we supplied to our robotics customer - 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.