HOLO-KROME 72120 5/16-18 X 1/2" 內六角螺絲 | 六角驅動 | 合金鋼熱處理黑氧化 (100個/包)

The hex socket drive fit perfectly on my torque wrench without any wobble, and the threads cut cleanly into the steel jig plate I was assembling. These feel much denser and more durable than the standard hardware store bolts I've used before.

The black oxide finish wiped clean with a rag and hasn’t shown a speck of rust after a week of oily shop use. The hex socket drive seated perfectly in my driver without any wobble, and all one hundred threads ran smooth into my jig plate.

These bolts finished my tooling cart assembly without a single stripped head, and the black oxide coating looks sharp against the steel frame. The hex socket drive gripped perfectly with a standard Allen key, and all 100 pieces in the pack had clean threads right out of the box.