Thanks to the cobalt steel blend, plan on sharpening these when the tips grow dull from use. Lacking a 1/4″ hex, use these in your drill or drill press when you need them for thicker, harder metals. The combination of the unique cutting head and the flute design landed these as our best drill bits for steel-particularly carbon steel. We love how quickly these bits drill and also how well they remove steel in tight, efficient spirals. The 135° split point tip helps when starting your hole and larger sizes feature a Chip Breaker-a groove at the midpoint of the cutting edge that further reduces heat buildup. The result is a more compact bit with a similar drilling depth. However, they also extended the flutes lower towards the shaft. Milwaukee countered this by making them a bit shorter than some others we’ve seen. The trade-off is that these bits thin out more towards the tip.

Their unique design not only helps them drill efficiently, but it also aids in cooling. How quickly? About 30% faster than most other 135° split-tip bits we tested against.

Listed in our best drill bits article, Milwaukee Red Helix cobalt bits use a variable flute design that clears away debris quickly. Best Drill Bits for Steel (Non-Hardened Carbon Steels) Milwaukee Red Helix Cobalt Drill Bits Even the best drill bits for stainless steel heat up over time, so be prepared to monitor heat buildup. Use cutting oil or similar lubricant when drilling into stainless and apply enough pressure to see a steady removal of material. With that said, stainless can actually harden up as it heats-so drilling slowly often helps you get through the material more efficiently. As a low-carbon steel, stainless steel has a natural hardness that comes without traditional hardening.ĭrilling stainless takes a strong bit-the same M42 cobalt bits we recommend above. Stainless steel alloy includes chromium (at least 10%) and nickel to make it corrosion-resistant. Hardened steel is a medium of high-carbon steel that gets heat-treated, quenched, and finally tempered. The same bits you use on hardened steel work on stainless. We have great news for anyone looking for the best drill bits for stainless steel. With a bit less cobalt in the steel blend, it just heats up a bit more quickly. The Irwin 29-piece Cobalt M-42 Metal Index Drill Bit Set performs very similarly to the M42 set. Pick up the Jobber Length Drill America D/A29J-CO-PC kit for just $113.Īlso good: Irwin 29-piece Cobalt M-35 Metal Index Drill Bit Set The round case makes it simple to remove the exact bit you need. It includes 29 bits in a shatterproof case. Use these bits when drilling tough, high-tensile strength materials like stainless steel-or even titanium. Drill America also doesn’t grind down the shafts on its larger bits-so you get more rigidity, but you also need a 1/2-inch chuck to drive them. Because of how hard they are, you can drill up to 30% faster than you can with conventional M2 high-speed steel bits. They come manufactured to the National Aerospace Standard 907. The jobber length bits work really well in cordless drills for onsite drilling. The bits feature the expected 135° split point, which gives you a nice, steady, and productive drilling speed. After testing with a multitude of materials, we selected their jobber bits as our best drill bits for hardened steel. Our best drill bits for hardened steel include the following: Best Drill Bits for Hardened Steel Drill America D/A29J-CO-PC 29-pc Cobalt Setĭrill America makes M42 cobalt bits that held up really well in drilling through anything we threw at them. Using a drill press is often the best way to get quality results. However, whatever differences there are between the outer look or chemical composition, both hardened steel and stainless steel are quite difficult to drill into. Because of rust and stain resistance, good luster, and low maintenance, it has many commercial uses including cookware, cutlery, home appliances, construction fasteners, and surgical instruments. Stainless steels are steel alloys consisting of at least 10.5% chromium and there are different grades. The best drill bits for metal could be designed for these hardened steel applications or they might be optimized for speed in softer carbon steels. Much of the steel materials that we see used in mechanical engineering, energy generation, and transportation are basically hardened steel. Hardened steels are durable and can be wear-resistant, corrosion-resistant, and abrasion-resistant. When we talk about drilling in hardened steel, we mean medium or high carbon steels typically made using a heat-treatment and tempering process.

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