براغي رأس مقبس M4-0.7 × 50 مم | محرك سداسي | خيط جزئي | سبيكة فولاذ من الفئة 12.9 مطلية بالزنك (300 / عبوة)

Installed these in a jig for a small precision press, and the Class 12.9 alloy steel holds up perfectly under high torque. The hex socket drive fits snugly without any stripping—charging just 40 cents each feels like a steal for this quality.

I’m using these 50mm screws to secure a tooling fixture on my mill, and the hex socket drive fits snugly with my wrench—no rounding or stripping so far. The zinc plating has held up well against shop grime and occasional coolant splashes, which is exactly what I needed for a precision assembly.

I needed a strong bolt for a jig I'm building, and the 12.9 alloy steel in these screws holds up perfectly under heavy clamping force. No stripped heads after several installations.