You have a project that needs to be completed but don’t know which drill bit is the right size for the job? Don’t worry – this article will help you figure out what size drill bit you need. With our helpful guide, you can quickly determine which drill bit is the right size for the holes you need to drill. We’ll cover the different types of drill bits, the different sizes available, and tips on choosing the right one for your project. So, if you’re wondering what size drill bit is right for your job, read on to find out!
How to Tell Drill Bit Size
Finding Drill Bit Size with a Ruler
A simple ruler can be used to measure the diameter of the drill bit. Place the drill bit on the ruler with the cutting edge facing up, and measure the length of the drill bit from cutting edge to shank. The diameter of the drill bit is the same as the length of the drill bit.
Measuring Drill Bit Size with a Caliper
A caliper is a tool used to accurately measure the diameter of a drill bit. Place the drill bit in the caliper and use the caliper’s jaws to precisely measure the diameter of the drill bit.
Comparing Drill Bit Size to Standard Measurements
Once the diameter of the drill bit has been determined, it can be compared to standard drill bit size measurements. Drill bits are typically measured in millimeters or inches and are labeled according to their diameter. The most common drill bit sizes are 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 11/64, 3/16, 13/64, 7/32, 15/64, 1/4, 17/64, 9/32, 19/64, 5/16, 21/64, 11/32, 23/64, 3/8, 25/64, 13/32, 27/64, 7/16, 29/64, 15/32, 31/64, and 1/2.
How to Determine the Size of a Drill Bit
Determining Drill Bit Size with a Drill Gauge
A drill gauge is a tool that can help you determine the size of a drill bit in two ways. First, it can measure the drill bit’s outside diameter, which is the diameter of the shank. Second, it can measure the drill bit’s flutes, which are the grooves in the bit that help create the hole. To use the gauge, place the drill bit in the gauge and compare the size of the bit to the size indicated on the ruler.
Estimating Drill Bit Size with a Drill Bit Chart
Another way to determine the size of a drill bit is to refer to a drill bit chart. Drill bit charts usually indicate the drill bit size according to its diameter and the type of material it is designed to drill. To use the chart, locate the type of material you plan to drill and the size of the drill bit you need. The chart will provide the size of the drill bit in both inches and millimeters.
Knowing how to determine the size of a drill bit is an important part of successful drilling. With the right information and tools, you can quickly and easily find out the size of a drill bit.
Drill Bit Diameter Comparison
Drill Bit Diameter by Number
Drill bits designated by number range from size 80 (the smallest) to size 1 (the largest). Size 80 is 0.0135 inch in diameter, with each increment double the diameter of the previous size. Size 1 measures 0.50 inch in diameter.
Drill Bit Diameter by Letter
Drill bits designated by letter range from size A (the smallest) to size Z (the largest). Size A is 0.234 inch in diameter, with each increment double the diameter of the previous size. Size Z measures 1.5625 inch in diameter.
Drill Bit Diameter by Fraction
Drill bits designated by fraction range from 1/64 inch (the smallest) to 1/2 inch (the largest). 1/64 inch is 0.0156 inch in diameter, with each increment double the diameter of the previous fractional size.
Drill Bit Diameter by Decimal
Drill bits designated by decimal range from 0.0312 inch (the smallest) to 0.5000 inch (the largest). 0.0312 inch is 0.7938 mm in diameter, with each increment double the diameter of the previous decimal size.
Drill Bit Shanks
Drill Bit Shank Types
The shank is the end of a drill bit grasped by the chuck of a drill. It is usually made to fit the respective drill chuck by its shape, size, and threading. Common types of drill bit shanks are straight, taper and hex.
Straight Shank Drill Bits
Straight shank bits are the most common type and are used for general purpose drilling. They are available in a variety of sizes, from small 1/16” bits to large 1” bits.
Taper Shank Drill Bits
Taper shank bits are used for heavier duty drilling applications. They provide more torque than straight shank bits, and are typically used in larger industrial drills, such as those found in machine shops.
Hex Shank Drill Bits
Hex shank bits are the most common type used in modern cordless drills. They provide more grip and torque than either straight or taper shank bits and are available in sizes ranging from 1/16” to 1/2”.
Drill Bit Length
- Drill bits come in a wide range of sizes and lengths. The length of a drill bit is determined by the overall length of the bit, including the shank.
- Determining the correct length of a drill bit is essential. If the bit is too short, it won’t reach the desired depth; if it is too long, it will cause the drill to become unstable and possibly cause an accident.
- Length is measured in inches. Common lengths include 3/4, 1/2, 3/8, 5/16, 1/4 and 1/8.
- Longer drill bits are typically used for deeper holes. For example, a 3/4-inch bit is used for drilling holes that are 1 inch deep.
- Shorter drill bits are generally used for shallow holes. For example, a 1/4-inch bit is used for drilling holes that are 1/2 inch deep.
Types of Drill Bits
Twist Drill Bits
Twist drill bits are the most common type of drill bit used. They come in a variety of sizes and are used for drilling into metal, wood, plastic, and other materials. They are usually made of high-speed steel and are available in both straight and tapered shanks.
Spade Drill Bits
Spade drill bits are used for quickly drilling large holes in softwood or plywood. They are designed with a flat, shovel-like cutting tip and a slightly curved body. They are available in different sizes and are commonly used for drilling pilot holes for screws.
Auger Drill Bits
Auger drill bits are designed for drilling holes in hardwoods. They are made of high-speed steel and have a twisted spiral flute that cuts into the material. They are available in a variety of sizes and are often used for drilling pilot holes for screws and lag bolts.
Step Drill Bits
Step drill bits are designed for drilling holes in thin materials such as sheet metal. They have a stepped cutting edge that allows them to drill a range of hole sizes from small to large. They are available in a variety of sizes and are often used for drilling pilot holes for screws and bolts.
Drill Bit Materials
Carbon Steel Drill Bits
Carbon steel drill bits are the most common type used for general purpose drilling and are suitable for most materials. They are typically the least expensive type of drill bit and are available in large sizes.
High-Speed Steel Drill Bits
High-Speed Steel drill bits are designed for drilling into harder materials and are often used for drilling into metals. They are more expensive than carbon steel drill bits and are not suitable for drilling into softer materials.
Cobalt Steel Drill Bits
Cobalt steel drill bits are designed for drilling into harder materials, such as stainless steel and cast iron. They are more expensive than high-speed steel drill bits, but are more resistant to wear and heat.
Titanium-Coated Drill Bits
Titanium-coated drill bits are designed for drilling into harder materials and are often used for drilling into metals. They are more expensive than carbon steel drill bits, but are more resistant to wear and heat.
Frequently Asked Questions
What type of bit should I use for drilling through metal?
- High-Speed Steel (HSS): This type of bit is great for drilling through steel, iron, and other metals. HSS bits are generally used for drilling through softer metals such as aluminum and copper.
- Carbide-Tipped: Carbide-tipped bits are ideal for drilling into harder metals like stainless steel. Carbide-tipped bits can also be used to drill through wood, but are not recommended for softer metals.
- Cobalt: Cobalt bits are specifically designed for drilling through harder metals. They are more expensive than HSS and carbide-tipped bits, but they can last longer and can handle tougher drilling jobs.
How do I know which drill bit size to use?
- Measuring the diameter of the hole: The first step is to measure the diameter of the hole you want to drill. This will help you determine the size of the drill bit to use.
- Checking the drill bit size chart: Once you have determined the diameter of the hole, you can then refer to a drill bit size chart to find the corresponding drill bit size.
- Using the right type of drill bit: Different types of materials require different types of drill bits. For example, a masonry bit should be used when drilling into brick or concrete. A wood bit should be used when drilling into wood.
- Considering the depth of the hole: When drilling a hole, you need to consider the depth of the hole as well. If you are drilling a deep hole, you may need to use a longer drill bit.
The right drill bit size is essential when drilling a hole. To ensure you have the correct size, measure the diameter of the hole, check a drill bit size chart, use the right type of drill bit, and consider the depth of the hole.
What type of bit should I use for drilling through wood?
Twist Bits: Twist bits are the most common type of drill bit and are used for drilling into wood and other soft materials. They are typically made of high-speed steel and have a twisted shaft and an angled point for making holes.
Brad Point Bits: Brad point bits are similar to twist bits, but they have a brad-like point at the tip which helps to keep the bit from wandering off course when drilling. They are commonly used for drilling into hardwoods.
Hole Saws: Hole saws are circular drill bits with teeth on the edge that cut out larger diameter holes. They are great for making larger openings in wood, such as for door locks or mounting brackets.
Forstner Bits: Forstner bits are used for making precise and clean holes in wood. They have a flat bottom and a center spur that helps to keep the bit from wandering off course when drilling. They are great for making mortises, pocket holes, and other intricate details.
Spade Bits: Spade bits are used for making large holes in wood. They have a wide, flat tip and a pointed center that helps to keep the bit from wandering off course when drilling. They are great for making openings for electrical outlets, switches, pipes, and other larger projects.
Can I use a Drill Bit More than Once?
Yes, you can, depending on the type of material you are drilling and the condition of the drill bit. For softer materials, such as wood and plastic, drill bits can be reused multiple times. However, for harder materials, such as metal and concrete, drill bits will usually need to be replaced after one use. Additionally, if the drill bit becomes dull or damaged, it should be replaced to ensure a successful drill job.
Are There Any Safety Precautions I Should Take When Using a Drill Bit?
Safety is of utmost importance when using a drill bit. Here are the key precautions to take:
- Always wear protective gear like safety glasses, ear protection and a dust mask.
- Use the correct drill bit for the material being drilled.
- Ensure the drill bit is properly installed in the drill.
- Keep fingers away from the drill bit when it is spinning.
- Always use a clamp to secure the material being drilled.
- Be aware of kickback when drilling.
- Keep power cords away from the drill bit.
- Don’t force the drill bit into the material, let it cut its own way.
- Remove the drill bit from the drill after use.
Follow these safety precautions when using a drill bit and you can help ensure a safe and successful project.
Conclusion
Choosing the right drill bit for your project can be tricky, but it doesn’t have to be. With the right information and a bit of research, you can easily determine the best size drill bit for the job. Keep in mind that the size and type of bit you choose will depend on the material you are drilling through and the project you are completing. By doing your research and having the right information, you can ensure the success of your project.
