These are custom metric socket cap screws with an undersized head diameter that we have provided to an aftermarket automotive product manufacturer for many years. Measuring M5 X 0.80M X 16MM, the socket cap screws are domestically manufactured in alloy steel material and then finished with zinc yellow finish. The final step involves the application of 1193S thread locking patch on each screw. Our internal part number for this custom item is DIN912-05016-C1193S.
