1/4-20 x 3/8" 內六角螺絲 | 低頭內六角驅動 | 合金鋼熱處理黑色氧化物 (300 個/包)

Used a handful of these to build a small jig for my drill press and the black oxide finish looks like it’ll hold up well against chips and oil. The low head design let me get a socket in tight spots where a standard cap screw wouldn’t have fit.

I was worried these would strip out under torque, but the alloy steel and black oxide held up perfectly on my jig project. The low head design let me fit them into tight spots where regular screws would have stuck out.

Finally, a low-profile screw that doesn't strip under torque—these black oxide ones held firm when I was adjusting my jig setup. The hex socket drive made install a breeze in tight spots.