Tap Bolt, Zinc Plated 8.8 - M16 Standard Thread
ISO general-purpose metric screw threads ("M" series threads) are defined in international standard ISO 68-1. Each metric ISO screw thread is designated by the letter M followed by the value of the nominal diameter. Standard "coarse" pitch listed in ISO 261.
Zinc plated Class 8.8 AS 1110 High Tensile Steel (per ASTM F568M) - Alloy steel; quench and tempered, 827 MPa tensile strength, 640 MPa yield strength.