Diameter: 16mm
Length: 60mm
Material: Steel
Finish: Black Phosphate
Head Style: Hex (#24 Wrench)
Thread Size: 2.0mm (Coarse)
Thread Length: 38mm
Hardness: Class 10.9
Type: Cap Screw
Specifications: DIN 931

Box of 20.

A hex cap screw has a hexagonal head, designed to be driven by a wrench.