7/16-14 X 3/8" 滾花杯點內六角止付螺絲 | 合金鋼 (100顆/包)

The hex socket drive made tightening these in a cramped engine bay much easier than I expected. They hold firm without stripping, and the alloy steel feels solid. Exactly what I needed for a secure fit.

Used these to lock down a pulley hub in a tight frame area—the knurled cup point bit into the steel like it meant it, no slipping. The hex socket took my ball-end Allen wrench without stripping, which is more than I can say for cheaper sets. Solid enough for the price, though the 3/8" length meant I

The hex socket drive made it easy to get these tightened down in a cramped spot on my gearbox. Alloy steel feels solid and the knurled cup point really bites into the shaft without slipping.