HOLO-KROME 87145 M8-1.25 x 50mm 六角穴付きボルト | 皿頭六角穴駆動 | 合金鋼 熱処理黒色酸化被膜 (100個/パッケージ)

I’ve used about 30 of these M8 screws mounting jig components, and every single one threaded in clean without any binding. The 50mm length is exactly right for heavy steel brackets, and the black oxide finish resists scuffing better than plain steel.

The thermal black oxide finish is what sold me—it’s got that uniform, matte look that resists fingerprints better than bare steel, and the flat heads sit perfectly flush in my jig fixtures. Hand-tightened a few into a tooling plate and the socket drive engaged cleanly with zero stripping.

Finally got these M8s for a precision fixture I'm building; the black oxide coating was perfectly uniform across all 100 screws, no burs or rough edges anywhere. The flat head seated flush into the countersink on first try, which saved me a ton of rework time.