HOLO-KROME 09054 16mm x 120mm 內六角肩螺絲 | 內六角頭 | 六角驅動 | 合金鋼 熱處理黑色氧化 (10/包)

The hex drive bites cleanly without stripping, and the ground shoulder slips into my bearing bore with zero slop. These are going to be my go-to for any axle job now.

I needed precise pivots for a custom jig, and these screws fit perfectly; the hex socket drive made installation straightforward. The black oxide coating hasn't shown any wear after repeated adjustments, which is exactly what I needed.

Finally got around to using these as axles for a small pulley system — the precision ground shoulder made alignment effortless. Grip of the hex socket drive was solid, no stripping even under decent torque.