M6-1 × 50mm ソケットキャップスクリュー | フラットヘッド 六角穴 | 部分ねじ | クラス12.9 合金鋼 熱処理黒色酸化 (200/パッケージ)

The black oxide finish looks sharp and held up fine during assembly, no chips or peeling. Threads were clean and the hex socket seated snugly, these are solid for jig work.

Installed these on a new tooling fixture and the black oxide finish holds up well to handling without smudging. The hex socket drive feels precise and the 12.9 grade gives me confidence they’ll hold torque.

The partial threading is perfect for our jig builds—grips tight where it matters and leaves clean clearance below. All 200 came out of the bag with uniform, smooth hex sockets and no burrs, so the driver seated every single time.