Drill Bits for Stainless Steel – Kennametal Buying Guide

When it comes to drilling through stainless steel, there are a few key factors to consider. One of which is that the material is prone to hardening, which means that it becomes harder and more difficult to drill as you continue to work on it. Additionally, stainless steel is a poor conductor of heat, which means that it can quickly become hot during the drilling process.

To overcome these challenges, it is essential to choose the right drill bit for the job. Here are some of the factors to consider when selecting drill bits for stainless steel:

• Material: Drill bits are typically made from high-speed steel (HSS), cobalt steel, or carbide. For drilling through stainless steel, solid carbide drill bits are the preferred material for precise holes and longevity of the tool.
• Coating: Most drill bits feature single layer or multi-layer coatings. They can be layered with titanium nitride (TiN), gold oxide, black oxide, or even a propriety coating to improve performance. Coated drill bits are more resistant to wear and heat buildup, making them an excellent choice for drilling through stainless steel.
• Point angle: The point angle of a drill bit refers to the angle at which the tip is ground. For stainless steel, typically a point angle of 135 degrees is ideal. This angle helps to reduce the amount of force required to drill through the material and reduces the risk of the drill bit slipping or walking.
• Flute design: The flute design of a drill bit refers to the shape and arrangement of the grooves that run along the length of the bit. For drilling through stainless steel, a bit with a helical flute design is recommended. This design helps to improve chip evacuation and reduce heat buildup, which can lead to longer bit life and better performance.
• Size: The size of the drill bit will depend on the size of the hole you need to drill. It is essential to select the appropriate size to ensure precision and accuracy in your drilling.
• Through-coolant capability: Stainless steel is a tough material to drill, and it can generate a lot of heat. If the drill bit gets too hot, it will dull quickly and may even break. To prevent this, through-coolant drill bit is preferred.

Now that we've covered some of the key factors to consider when selecting drill bits for stainless steel, let's take a closer look at some of the specific types of drill bits that are best suited for this material. 

Solid Carbide Drill Bits: 

Carbide drill bits are the most durable and long-lasting type of drill bits available. They are extremely durable and can withstand the high-temperatures and pressures of drilling stainless steel. 

• KenDrill™ SGL: SGL drills are a high-performance option for drilling stainless steel and high-temperature alloys. They are engineered with a unique SGL-Point-Geometry and coated with KCMS15 grade, which provides excellent wear resistance and high hardness. As a result, SGL drills can be used for a variety of applications, including MQL machining of steel.
• Y-TECH™ Drill: Y-TECH™ drills are a high-performance option for drilling difficult-to-machine materials. They offer superior hole accuracy and are designed to avoid chipping. If you are looking for a drill bit that can handle difficult materials, Y-TECH™ drills are a good option to consider. 
• GOdrill™: GOdrill is a high-performance microdrill that offers several benefits, including long tool life, free flow of chips, and a wide range of applications.
• Kenna Universal: The Kenna Universal drill series is a versatile and high-performance tool that can be used for a variety of drilling applications. The series offers a wide range of diameters, can drill up to 12xD, and is ideal for drilling cross holes, inclined exit holes, deep holes, and chamfer holes in a variety of materials, including stainless steel. 

Drilling through stainless steel can be a challenging task, but with the right techniques and tools, it can be done with ease. Here are some tips to help you drill through stainless steel with ease:

• Use lubricant: Stainless steel generates a lot of heat when drilling, which can cause the bit to overheat and wear out quickly. Using a lubricant such as oil or cutting fluid will reduce the heat and friction, allowing the bit to last longer and drill more smoothly.
• Start with a smaller bit: When drilling through stainless steel, it is best to start with a smaller bit and gradually work your way up to the desired size. This will help prevent the bit from overheating and breaking and reduce the risk of walking.
• Secure the material: Stainless steel is a hard and slippery material, which can make it difficult to drill through. To prevent the material from moving or slipping, secure it tightly in a vise or clamp.
• Use the right speed: Drilling too fast or too slow can cause the bit to overheat or break. It is essential to use the right speed for the size and type of bit you are using. A general rule of thumb is to use a slower speed for larger bits and a faster speed for smaller bits. 
• Use the right pressure: Applying too much pressure while drilling can cause the bit to overheat or break. It is important to use a steady and consistent pressure while drilling, allowing the bit to do the work.

Drilling stainless steel requires the right techniques and tools. Using lubricant, starting with a smaller bit, securing the material, using the right speed, and applying the right pressure will help you easily drill stainless steel. With these tips, you can achieve a smooth and accurate drilling experience for your machining operations.