M12 x 30mm 內六角肩螺絲 | 內六角頭 | 內六角驅動 | 18/8 不鏽鋼 (25 / 包)

The shoulder is machined so precisely that these screws slide into a reamed hole with zero play. I used them as axle pins for a small mechanism, and the 18/8 stainless feels solid without being too heavy.

I used these as pivot pins for a custom jig and the ground shoulder spun smoothly with zero wobble, which is exactly what I needed. The hex drive seated firmly in my wrench and all 25 arrived clean with sharp threads.

The precision-ground shoulder on these made setting up a custom hinge mechanism much smoother than I expected with off-the-shelf hardware. The stainless finish looks clean and hasn't shown any wear after a week of constant pivoting.