5/16-24 x 7/8インチ ソケットキャップスクリュー | 六角ソケットドライブ | アメリカ製 | 合金鋼 サーマルブラックオキサイド (1000個/パック)

Needed a solid batch of black oxide fasteners for a tooling project, and these have held up perfectly under repeated wrenching. The hex socket drive really does grip without stripping.

Ordered a thousand of these for our jig builds and the hex socket drive seated perfectly every time—no stripped heads on the first pass. The thermal black oxide gives them a nice uniform look and they’ve held up through a week of heavy clamping without any rust.

The black oxide finish on these screws is much more consistent than the last batch I got elsewhere, and the hex socket drive makes them easy to work with on my jigs. Each one threads smoothly without any binding.