M16-2×75mm ソケットキャップスクリュー | 六角ドライブ | 部分ねじ | クラス12.9 合金鋼 熱処理黒色酸化皮膜 (25個/パック)

Finally had to replace some worn-out bolts on a large press fixture; these M16s threaded in smoothly and the black oxide finish is holding up nicely against oil and chips. The hex socket drive made installation a breeze with a ball-end driver.

Installed these as heavy-duty jig bolts and the hex socket drive handled a high-torque impact driver without stripping. The 12.9 alloy steel feels noticeably tougher than the cheaper grades I've used before.

The black oxide finish on these M16 screws has held up beautifully in my jig setup—no rust after weeks of coolant exposure. The hex socket drive seated perfectly with my torque wrench, and the 12.9 alloy steel feels rock solid when cinching down heavy tooling.