M16-2 x 150mm 內六角螺絲 | 六角驅動 | 半牙 | 12.9級合金鋼 熱處理黑色氧化 (20顆/包)

The black oxide coating looks really uniform across all 20 of them, and the partial threading gave me just the grip I needed for a jig build. Torqued them down to spec without a hint of stripping, and they've held perfectly through a week of heavy use.

Threads are clean and the 12.9 alloy steel feels seriously tough when torquing down jigs. The black oxide finish gives them a nice, uniform grip in the wrench, no slipping. Used a full pack on a custom fixture and not one stripped or bent.

The hex socket drive seated perfectly on my Allen wrench with zero wobble, and the 12.9 alloy steel feels rock solid for the jig I'm building. Threading was smooth all the way down, though I wish they came with a few extra washers in the pack.