M6 x 40mm HoloKrome Socket Countersunk (Allen) Screw in Black Oxide Steel 12.9 - ISO 10642 (DIN 7991)

Holo-Krome branded socket countersunk screws (or flat head screws), in alloy steel with a strength grade of 12.9, and a black oxide finish. Manufactured in the USA, Holo-Krome are high quality screws, similar to Unbrako, with precision 3A threads for greater clamping force. Conforming to ISO 10642/DIN 7991, these require a hex socket/allen key to fit. The countersunk head is used in conjunction with a countersunk hole or countersunk washer.