M2-0.4 x 16mm 內六角螺絲 | 六角驅動 | 全牙 | 12.9級合金鋼鍍鋅 (600個/包)

The zinc plating on these is surprisingly even across all 600 pieces, no gunk in the hex sockets to slow down my driver. They seat perfectly in the precision assembly I'm working on, and the 12.9 alloy steel feels rigid under torque. Bulk pricing for this grade is hard to beat.

Installed these on a custom jig for delicate PCB alignment—the 12.9 alloy steel is noticeably harder than standard stainless, and the zinc plating makes them easy to see against dark fixtures.

I've been through three packs of these on my jigs and tooling, and the 12.9 alloy steel holds up far better than the cheaper 8.8s I used to burn through. Zinc plating hasn't shown a hint of rust even after sitting in my damp shop. For precision assemblies, the fully threaded length makes alignment a