3/8 DIA X 1/2" LTH BARREL LOW PROFILE FLAT HEAD SEX BOLTS, 316 SS 7/32" HEX DRIVE 1/4-20 X 3/8 TAP DEPTH 25/32 HEAD DIA X 3/32 HEAD HT - Z1518 | AMPG https://ampg.com/product-details/socket-drive-flat-and-low-profile-barrel/z1518