M4 Hex Set Screw Bolt Washer High Tensile BZP M4, Hexagon Head, Set Screw (0.7mm Pitch, Standard Coarse Thread), High Tensile (8.8), Plus Washer Zinc Plated, BZP, DIN 933. Hex Head Set Screw is similar to a hex head, bolt and can be used in a similar way.