5/16-18 x 1″ Security Machine Screw – Button Hex Socket Head – Alloy Steel – Black Oxide – 100 Pk Best Price

Security fasteners provide an added level of security by their drive design that prevents removal with ordinary screw drivers. Maximum torque transfer & positive tool engagement means easier drive installation with less pressure & slippage. Requires matching driver bit.
Button Head screws are typically used for general purposes with a lower crown & shallower recess than round head screws.