3/8-16 x 5/8英吋 內六角螺絲 | 圓頭 內六角驅動 | 尼龍防鬆 | 全牙 | 合金鋼 熱處理黑氧化 (100個/包)

The nylon pellet on these hex socket screws locked in place perfectly during my jig assembly, and the black oxide coating looks clean without any flaking. They seated flush with my tooling plate, making alignment much simpler than standard cap screws I've used before.

My bench has been through a lot of these for jig setups and the black oxide finish is holding up great without any rust after a few months of shop use. The hex socket drives bite cleanly and the nylon pellet gives me confidence they won't back out under vibration.

The nylon pellet locking feature is exactly what I needed for a tooling fixture that gets constant vibration. These button heads seat flush and the black oxide finish hasn't shown a speck of rust after a month on the shop floor.