Four Pack 1/4-28 Threaded Drill Bits Set Cobalt Steel With Black Oxide Finish Sizes 40, 30, 21, 12 Pro Grade For Precision Metalworking DIY Projects Durable And Long Lasting

Four-Pack 1/4-28 Threaded Drill Bits in Cobalt Steel
✔️ Four pieces, 1/4-28 threaded, sizes #40, #30, #21, #12, cobalt steel

This four-piece set contains 1/4-28 threaded drill bits crafted from cobalt steel with a black oxide finish. It’s a handy choice for precision drilling in metalworking, shop projects, and DIY fabrication.

✅ Material: cobalt steel with black oxide finish
✅ Thread: 1/4-28; sizes #40, #30, #21, #12
✅ Finish: wear-resistant black oxide coating
✅ Applications: precision drilling for metalworking and DIY projects

💡 What is the best way to use 1/4-28 threaded cobalt drill bits for metalworking? This handy guide explains how to get clean, precise holes.

- For drilling steel and aluminum, start with a center punch and use moderate speed.
- Keep bit cool with lubrication and avoid overheating; re-lubricate as needed.
- Use a drill press or guide to maintain straight holes and prevent wandering.
- Select the correct pilot point and feed rate for best results.
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