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  • August 10, 2024

Best Drill Bits for Stainless Steel,how to choose?


Stainless steel material is difficult to drill, because of its high hardness, easy work-hardening, low thermal conductivity, toughness and the surface of the dense oxide layer, these characteristics make the drilling requires more force, more wear-resistant drill bit and better cooling measures. Therefore, it is especially important to choose the right drill bit when drilling.


1.Choose the right material

Cobalt Drill Bits for stainless steel

- Cobalt Drill Bits: Give preference to HSS drill bits containing cobalt (M35 or M42) as they are more heat-resistant and harder, making them ideal for drilling stainless steel.

- Carbide Tipped Drills: For higher strength applications, choose carbide tipped drill bits, which are capable of handling harder materials.

-If you choose the wrong drill bit using common materials, the stainless steel material is too hard, which tends to make the common drill bit wear out quickly, drilling efficiency is low, and may even lead to drill bit breakage.


2. Select the appropriate coating

- Titanium Nitride (TiN) Coating: Choose drill bits with TiN coating, which can reduce friction, prolong the life of the drill bit, and improve drilling efficiency at the same time.

Cobalt Drill Bits for stainless steel

- Black Oxide Coating: This coating reduces heat buildup and is corrosion resistant.

Cobalt Drill Bits for stainless steel

- Coating reduces friction and heat. Choosing an uncoated drill bit, or choosing an unsuitable type of coating, can lead to premature wear of the drill bit and excessive heat generation during drilling


3. Drill Tip Angle

Cobalt Drill Bits for stainless steel

-135 Degree Split Point Design: Choose a drill bit with a 135 degree split point design as it reduces slippage and helps to cut quickly on stainless steel surfaces.

- 118 Degree Standard Point: In some cases, a standard 118 degree drill bit will do the job, but requires more careful handling.

- Although there are some situations where a 118 degree standard drill bit can be used, it may be difficult to drill accurately, increasing drilling difficulty and bit wear, so a 135 degree split point design is more recommended


4. Use the appropriate drill bit size

- Match the hole size: Ensure that the drill bit size is appropriate for the hole size you require and also for the strength of the stainless steel to minimize the risk of bit breakage or wear.

-Inappropriate sizing can lead to inaccurate drilling and mismatched hole diameters, making machining more difficult.


5. Consider drill bit design

-Spiral flute design: Choose a drill bit with an effective spiral flute design, which helps to evacuate chips and minimize heat build-up, especially when drilling difficult materials such as stainless steel.

- Inadequate designs can lead to difficult chip evacuation and increased heat buildup in the drill hole, affecting drilling results and bit life.


When choosing a drill bit suitable for stainless steel materials, preference should be given to cobalt or carbide drill bit with TiN or black oxide coatings with a 135-degree split-point design to ensure drill efficiency and durability. If you would like to know more, you can also contact us by clicking here.

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