8mm Drill Bit
Choosing the Best 8mm Drill Bit for Metal: The Ultimate Guide
When selecting an 8mm drill bit, it’s crucial to choose the right tool for the material you’re drilling. Whether you’re working with metal, stainless steel, or other tough materials, the right drill bit can make a significant difference in efficiency and precision. Here, we’ll explore everything you need to know about the 8mm drill bit for metal, including the best materials for various applications and why cobalt drill bits stand out.
What Is an 8mm Drill Bit?
An 8mm bit refers to a drill bit with a diameter of 8 millimeters, commonly used for drilling into materials like metal, wood, plastic, and more. It’s a versatile size that is popular among both professionals and DIY enthusiasts. However, when it comes to drilling metal—especially harder materials like stainless steel—selecting the right drill bit is essential for achieving clean and precise holes.
Why Choose an 8mm Drill Bit for Metal?
When drilling into metal, the material of your drill bit plays a crucial role in determining how effective and durable the drilling process will be. Drill bits for metal come in several variations, each suited to different types of metal and drilling conditions. Let’s break down the most common materials used for drill bits for metal:
1. HSS (High-Speed Steel) Drill Bits
HSS drill bits are often seen as budget-friendly options for drilling softer metals. However, HSS drill bits are not the best choice when drilling harder metals like stainless steel or aluminum. They can wear out quickly when used on tougher materials, leading to reduced efficiency and performance. While affordable, HSS drill bits are typically recommended for lighter, non-industrial applications.
2. Titanium Drill Bits
Titanium-coated drill bits offer a longer lifespan than HSS bits, but they still don’t match the durability or heat resistance of cobalt bits. titanium drill bits work well for light-to-medium metals but can struggle when faced with more challenging materials like stainless steel.
3. Carbide Drill Bits
Carbide drill bits are high-performance tools known for their hardness and durability. While they are excellent for very tough materials and industrial-grade work, they come with a hefty price tag. 8mm carbide drill bits are often used in specialized, high-volume production settings. For general DIY or professional use, cobalt drill bits tend to offer a better balance of cost and performance.
4. Cobalt Drill Bits
For many, the 8mm cobalt drill bit is the go-to choice for drilling metal, particularly harder metals like stainless steel. Cobalt drill bits are made from a blend of high-speed steel and cobalt, which enhances their hardness and heat resistance. These drill bits are particularly effective for drilling through tough materials without losing sharpness or getting damaged due to heat buildup.
Why are cobalt drill bits preferred? They are relatively affordable compared to carbide, and their superior heat resistance means they can be used for longer periods without overheating. This makes them ideal for mechanics, DIY enthusiasts, and professionals who need reliable and consistent drilling performance.
A conventional 8mm cobalt drill bit for metal typically has a length of around 117mm, but longer drill bits are available from specialist suppliers for deeper drilling tasks.
Choosing the Right 8mm Drill Bit for Stainless Steel
When it comes to drilling stainless steel, using the correct drill bit is crucial to prevent wear and damage. An 8mm drill bit for stainless steel should be made from a material capable of withstanding high levels of heat and pressure, such as cobalt. Cobalt drill bits are especially effective for stainless steel because they maintain their sharpness and can drill through this tough material with ease.
Conclusion
Selecting the best 8mm drill bit for metal depends on the specific application and material you’re working with. While HSS and titanium bits may suffice for lighter tasks, cobalt drill bits provide the durability and heat resistance needed for more demanding jobs, including drilling stainless steel. For DIY enthusiasts, mechanics, and professionals alike, cobalt bits strike the perfect balance between performance and cost-effectiveness.
For reliable performance and consistent results, always choose an 8mm cobalt drill bit when working with metals like stainless steel and other tough materials.
A conventional 8mm cobalt drill bit for drilling metals will have an overall length of 117mm
Longer drill bits can be bought from specialist suppliers
Which 8mm drill bit should you buy?
When buying any drill bit for drilling metal it is important to buy one which has a number of excellent cutomer reviews.
Ideally the manufacturer should be able to show a testing certificate indicating the hardness of the drill bit. And of course a supplier which offers a 100% money back guarantee is likely to be supplying a quality drill bit.
Drilling metal with 8mm drill bit – what speed?
When drilling metal with any drill bit it is important to drill at the correct speed. Drilling at too high a speed will cause the drill bit to overheat. It can also cause a metal to ‘work harden’ so it is advisable to drill slower rather than faster.
The below drilling speed chart will tell you the correct speed to drill at. This will depend on the metal you are drilling through plus the size of the drill bit you are using.
Do not worry if you are unable gauge the exact speed of your drill. The most important thing is not to drill too fast. So if you have an adjustable speed drill then start off slow.
The main object is to avoid overheating your 8mm drill bit. So apart from drilling slow you should take breaks and use a drilling lubricant.
8mm drill bits Top Tip For Drilling Metal
If you are drilling any metal it is important to use a metal lubricant. This is especially important when using a larger bit like an 8mm drill bit. Larger drill bits will generate heat more quickly thank smaller ones. So apart from drilling slowly and using reduced pressure it is very important to use a lubricant.
A good quality lubricant will contain High Pressure Additives. This will reduce the friction whilst drilling and assist in controling the temperature. Ultimately increasing the life of your 8mm drill bit.
8mm drill bit to inches
An 8mm drill bit is approximately 0.314961 inches
FAQ’s 8mm metal bits
Q: What materials can a 8mm drill bit cut?
A: A 8mm cobalt drill bit can cut stainless steel, hardened steel and other tough metals, while HSS is better suited for softer metals.
Q: Is a 8mm cobalt drill bit good for stainless steel?
A: Yes, an M35 cobalt 8mm drill bit is ideal for stainless steel, as it resists heat and avoids work-hardening.
Q: How long is a 8mm drill bit?
A: A standard 8mm cobalt drill bit is approximately 93mm long, though longer jobber lengths are available from specialist suppliers.
Q: What is 8mm in inches?
A: 8mm converts to approximately 0.31496 inches.
Q: Do I need lubricant when drilling with a 8mm drill bit?
A: Yes, always use cutting paste or oil when drilling with a 8mm bit to reduce heat and extend tool life.
Video tutorial / tips on drilling harder metals
