What Metal Are Drill Bits Made From? | The Material Decoded

Drill bits are primarily made from High-Speed Steel (HSS), an alloy of carbon, tungsten, chromium, and vanadium; for harder metals, bits are made from Cobalt Steel or Solid Carbide, while “Titanium” bits are actually HSS with a titanium nitride coating.

Picking up a drill bit and knowing what metal it’s made from is the difference between a clean hole and a ruined workpiece. Most bits sold for general use are High-Speed Steel (HSS), but the material changes completely when you move to stainless steel, hardened steel, or production work. The wrong metal choice wastes your time and snaps bits. This guide breaks down each drill bit metal, what it handles, and where it fails.

What Is High-Speed Steel (HSS) And What Is It For?

High-Speed Steel is the most common drill bit material for general-purpose drilling. Its name comes from its ability to cut at higher speeds without losing hardness — a trait standard carbon steel bits lack. HSS is an alloy blend of carbon, tungsten, chromium, and vanadium, which lets it resist the heat generated by friction in metal and wood.

HSS bits handle soft steels, aluminum, brass, plastics, and wood. They are affordable and hold up well in portable drills and drill presses. The trade-off is that HSS dulls faster on harder metals like stainless steel, and it loses its temper if the cutting edge overheats from lack of lubrication.

When Should You Use Cobalt Drill Bits?

Cobalt bits, technically called HSCO (High-Speed Steel with Cobalt), are an upgrade for drilling into harder metals. These bits blend 5–8% cobalt into the HSS base, which lets them retain their cutting edge at much higher temperatures. That makes them the right choice for stainless steel, titanium, and other tough alloys that wreck standard HSS.

Cobalt bits are more brittle than HSS, so they can chip if you apply too much side force or use them in a wobbly hand drill. They also cost more. But for someone drilling into stainless steel regularly, the extra cost is recovered in fewer broken bits and faster work. If you are choosing a bit specifically for tough steel, check out our tested recommendations for the best bit for drilling stainless steel.

What Makes Carbide Bits Different And Harder?

Solid carbide bits are the hardest and most brittle drill bit material available. Made from tungsten carbide particles bonded with a metal binder, they can cut through hardened steel, concrete, and abrasive materials that would destroy HSS and cobalt bits. Carbide is also the material used in most production and CNC drilling operations.

The critical rule with carbide — and a common expensive mistake — is that carbide bits should never be used in hand drills or standard drill presses. Their brittleness means any vibration or misalignment causes them to snap or chip instantly. They require high-quality rigid tool holders and automated machinery. For home shop or portable use, stick with cobalt for hard metals.

Is Titanium A Real Drill Bit Metal Or A Coating?

This is the most common point of confusion. Titanium is not a base metal for drill bits — it is a ceramic coating, most often Titanium Nitride (TiN), applied to a standard HSS bit. The golden color that makes “titanium bits” recognizable is actually the TiN coating. That coating increases surface hardness, reduces friction, and can extend bit life three times over uncoated HSS.

A titanium-coated bit is still HSS underneath. It works well for wood, metal, fiberglass, and PVC, but it does not make the bit capable of drilling stainless steel or hardened materials the way a solid cobalt bit does. If you see a cheap set of gold-colored bits, you are buying coated HSS, not a different metal.

How To Identify A Metal Drill Bit By Looking At Its Tip

Metal drill bits have a distinctive tip shape that tells you immediately what they are for. Unlike wood bits that have a sharp centering point (a brad point), metal bits have a conical tip with two sharp cutting edges that meet exactly in the center. There is no centering point.

Because metal bits lack a centering point, you must center punch the spot where you want the hole before drilling. Without that dimple, the bit wanders across the surface. This is the single most common drilling mistake beginners make — gripping the workpiece tighter instead of taking one second to center punch it. Grainger’s KnowHow provides a clear video breakdown of which bit does the job based on material.

Drill Bit Point Angles And Why They Matter For Metal

The angle of the cutting tip is matched to the material you are drilling. Using the wrong angle makes the bit grab, skid, or burn the workpiece.

For stainless and mild steel, the standard tip angle is 118–135 degrees. Aluminum works best with a wider angle of 90–135 degrees — the wider angle prevents chip packing. Brass requires 90–118 degrees to stop the bit from grabbing and pulling into softer material. These specifications come from established engineering standards that have held for decades.

Does Black Oxide Change The Base Metal?

Black oxide is another surface treatment, not a different metal. A black oxide finish is a chemical conversion coating applied to HSS bits. It reduces friction, helps chips flow out of the hole, and provides mild corrosion resistance. It makes a standard HSS bit last longer in general-purpose use.

There is one compatibility rule to remember: black oxide is not recommended for drilling aluminum, magnesium, or similar materials. The treatment can cause galling — where the aluminum sticks and welds to the bit. For those materials, plain HSS or a coated bit without black oxide is better.

Real-World Guide To Choosing The Right Bit Metal

If this is your first time drilling metal, the actionable starting point is a set of cobalt bits for anything harder than mild steel and standard HSS for everything else. The extra dollar you spend on cobalt over HSS is cheaper than replacing a broken bit mid-project.