M6-1 x 16mm 內六角圓頭螺絲 | 半圓頭內六角驅動 | 全牙 | 10.9級合金鋼 熱處理黑色氧化 (600入/包)

The hex socket drive seats perfectly with a standard Allen key, and the black oxide finish feels consistent across all 600 pieces. Threads ran clean through steel plate without a single binding or stripped head. Solid deal for a full box of Class 10.9 hardware.

I needed a bulk supply of these for a custom jig build, and the hex socket drive makes tightening them in tight spaces so much easier than a traditional hex head. The Class 10.9 rating gives me confidence they'll hold up under repeated use without stripping.

Installed a full set of these on a custom tooling fixture and every single screw threaded perfectly without any binding. The black oxide coating feels durable and hasn't scratched during tightening.