Drill Bits for Stainless Steel (Which One to Choose) Uses and Functions

Stainless steel is a tough metal and one of the most commonly used metals in the automobile industry. Drilling holes in steel requires sturdy bits with sharp cutting edges. You need to make an informed decision about the drill bit’s size, length, flute design, and metal finish as they determine the strength of your bit.

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Features of Drill Bits for Stainless Steel

The following factors determine the suitability of a drill bit for stainless steel. Have a look.

Construction material

These drill bits are made of High-Speed Steel material that exists as either a metal alloy or solid carbide. HSCO drill bits are made of a strong alloy of steel with 5% or 8% cobalt content.

Other drill bits in this class have black oxide or titanium nitride finishes (TiCN and TiN). They allow for high-temperature resistance and durability. Therefore, the construction materials determine the durability, resistance, and cutting strength of your tool.


Three length dimensions apply for stainless steel drill bits: short, long, and extra long. The short length is sturdy and does not easily break, while the extra-long (jobber length) is the flying length. It has high drilling and cutting precision compared to the short length bits.

Flute type

The numbers of cutting blades form a flute. Twist drill bits with a spiral flute have a clear-cutting precision that makes them more suitable. The faster rate of chip removal also helps avoid overheating which is a major cause of drill bit blunting.

Cutting points and angles

Stainless steel is a hard metal, unlike aluminum, iron, and copper. 118 and 135 degree-bits are most appropriate. They are of high precision and their cutting points bite into metal without slipping.

Besides, new drill bits in this class cut well into metal than any other bits. Split point bits and twist drill bits are great for working on steel. Besides, step drill bits also make a suitable option.

Bit sizes

Large diameter bits are sturdy and stable to work on stainless steel. Smaller bit sizes may break and that’s why there are specific diameter measurements for stainless steel drill bits.

What are the Appropriate Drill Bits for Stainless Steel

From the features above, the best HSS bits with these finishes top the list of drill bits for stainless steel. Let’s find out.

Titanium drill bits

Not all titanium drill bits fall in this category. Step drill bits have a C-groove cutting edge that’s sharp enough for cutting in hard and soft metals. TiN and TiCN coatings make them resistant to overheating.

Black oxide drill bits

The oxide finish makes them stronger than ordinary HSS drill bits. It also affects their durability and cutting strength for stainless steel and other hard metals.

Tungsten carbide bits

Carbide bits have high heat resistance, cutting ability, and strength like a diamond. Moreover, it is used with high-impact drivers to drill into hard metals like steel. The fact that it’s not affected by heat makes it a perfect choice of tool for drilling in stainless steel without easily dulling.

HSCO bits

Cobalt-coated drill bits are excellent for cutting metals. Their hardness makes them a good choice for stainless steel drilling. Stainless steel generates a lot of heat.  However, with constant lubrication with machine oil, cobalt bits can do a perfect job.

Cobalt twist drill bits with the spiral flute remove chips faster, therefore, reduce overheating. It also has high drilling speeds for a faster drilling action.


If you need high-quality bits, the above types of drill bits for stainless steel should be the perfect investment. Since stainless steel is highly valued, you need premium drill bits for a clean finish and increased productivity. Standard drill bits may be too expensive because of the constant replacements as high heat shortens bit life. We hope that this information should guide you as you purchase drill bits for your stainless steel projects.