Roll Form Tap Drill Size Calculator

Roll form tap drill sizes depend on the metric thread size and pitch. For example, for an M8 roll form tap with a pitch of 1.25mm, a recommended drill size is approximately 6.8mm. These sizes may vary slightly based on specific applications and materials, so it’s essential to consult a tap drill chart or manufacturer’s guidelines for precision.

Metric Thread Size (M)	Pitch	Roll Form Tap Drill Size (Approx.)
M3	0.5mm	2.5mm
M4	0.7mm	3.3mm
M5	0.8mm	4.0mm
M6	1.0mm	5.0mm
M8	1.25mm	6.8mm
M10	1.5mm	8.5mm
M12	1.75mm	10.3mm
M14	2.0mm	12.0mm
M16	2.0mm	14.0mm
M20	2.5mm	17.5mm
M24	3.0mm	21.0mm
M30	3.5mm	26.5mm

FAQs

What is the formula for finding the tap drill size for a form tap? The formula for finding the tap drill size for a form tap is typically the nominal diameter of the thread minus the pitch diameter of the thread. This may vary depending on specific thread standards and form tap designs.

What size is the M8 roll tap? The M8 roll tap generally has a major diameter of approximately 8mm.

What size drill is an M14 1.5 roll tap? To estimate the tap drill size for an M14x1.5 roll tap, you can use a drill bit with a diameter of around 12.5mm.

What size hole do you drill for a 1/2 tap? For a 1/2 inch tap, you can use a drill bit with a diameter of approximately 17/32 inch or 13.5mm.

What is the rule of thumb for tap drill size? The rule of thumb for tap drill size is to use a drill bit that is slightly smaller than the major diameter of the thread being tapped. The exact size may vary depending on thread type and material, but a good starting point is typically about 75-80% of the major diameter.

What is a tap drill chart? A tap drill chart is a reference tool that provides recommended drill bit sizes for various tap sizes and thread types. It helps users select the appropriate drill bit for tapping holes.

What size hole do I drill for an M8 tap? For an M8 tap, you can use a drill bit with a diameter of approximately 6.8mm.

What is the difference between a roll tap and a cut tap? A roll tap and a cut tap are both used for threading, but they work differently. A roll tap is designed to form threads by displacing the material without removing it, resulting in stronger threads in some materials. A cut tap, on the other hand, removes material to create threads and may be more suitable for harder materials.

What size hole do I drill for an 8mm tap? For an 8mm tap, you can use a drill bit with a diameter of approximately 6.8mm.

Is M14 14mm? Yes, in the context of metric threads, M14 refers to a thread size with a major diameter of approximately 14mm.

What size drill bit do I use for a 1/2-14 tap? To estimate the tap drill size for a 1/2-14 tap, you can use a drill bit with a diameter of around 29/64 inch or approximately 11.5mm.

What is M14x1.5 in standard? M14x1.5 refers to a metric thread with a major diameter of approximately 14mm and a pitch of 1.5mm.

What size drill for a 1/2-20 tap? For a 1/2-20 tap, you can use a drill bit with a diameter of approximately 29/64 inch or around 11.5mm.

How deep should a drill be for a tap? The depth for tapping depends on the specific application and the length of the threaded portion required. Typically, you want to drill to a depth slightly deeper than the length of the threaded section on the tap.

What size drill for a 1/4-20 tap? For a 1/4-20 tap, you can use a drill bit with a diameter of approximately 13/64 inch or around 5.2mm.

Should the drilled hole be bigger or smaller than the bolt diameter for tapping? The drilled hole for tapping should generally be smaller than the bolt diameter to ensure proper thread engagement. However, the exact size depends on factors like the type of tap and the material being tapped.

Do you drill or tap first? You typically drill a hole first and then tap it to create threads. Drilling provides a starting point for the tap to create threads in the material.

What is the formula for tapping depth? The formula for tapping depth is the total depth of the hole minus the length of the threaded portion on the tap. It ensures that the threads are formed to the desired depth.

How do you use a tap drill chart? To use a tap drill chart, you find the thread size you’re working with, and the chart will provide the recommended drill bit size for creating a hole before tapping. You select the drill bit size based on the desired thread engagement and the type of tap you’re using.

What are the 3 sets of tap drill? The three sets of tap drill include taper, plug, and bottoming taps. Each type of tap has a different thread length and is used for specific applications.

How do you read a drill tap size chart? To read a drill tap size chart, locate the thread size you need, and the chart will indicate the recommended drill bit size to use before tapping. It may also provide information on tap types (e.g., taper, plug, bottoming).

What is the tap drill size before tapping the threaded holes? The tap drill size is the hole size you create before tapping the threaded holes. It is slightly smaller than the major diameter of the thread being tapped.

What size hole for a 1/8 inch tap? For a 1/8 inch tap, you can use a drill bit with a diameter of approximately 7/64 inch or about 2.8mm.

What size drill bit for an M8x1.25 tap? To estimate the tap drill size for an M8x1.25 tap, you can use a drill bit with a diameter of around 6.75mm.

What are the advantages of roll tap? Roll taps are known for producing stronger threads, reducing chip formation, and generally requiring less torque than cut taps. They are often used in high-production manufacturing.

What are rolling taps for? Rolling taps are primarily used for creating threads in ductile materials like aluminum, brass, and certain plastics. They work by displacing material to form threads instead of cutting it.

What is the best tap for hand tapping? For hand tapping, a taper tap is often recommended because it’s easier to start and requires less force to turn compared to plug or bottoming taps.

Can you use a 7mm drill for an M8 tap? Using a 7mm drill for an M8 tap is generally not recommended because it may result in loose threads. It’s better to use a drill bit close to the recommended size of approximately 6.8mm for M8 tapping.

Is an M8 drill bit 8mm? No, an M8 drill bit is not 8mm in diameter. It is typically slightly smaller, around 6.8mm in diameter, to accommodate the threads created by an M8 tap.

What size drill bit for a 1/8 inch NPT tap? To estimate the tap drill size for a 1/8 inch NPT (National Pipe Taper) tap, you can use a drill bit with a diameter of around 11/32 inch or approximately 8.7mm.

Why was the M14 phased out? The M14 rifle was phased out of widespread military use in the United States primarily due to issues related to the rifle’s weight, recoil, and ammunition capacity. It was replaced by the M16 rifle, which was lighter and had a higher ammunition capacity.

What is the modern M14 called? The modernized version of the M14 is often referred to as the M14 Enhanced Battle Rifle (EBR) or M14 EBR-RI (Reception Integrated). These variants incorporate various improvements over the original M14 design.

Is 14mm equal to 9/16 inch? No, 14mm is not equal to 9/16 inch. 14mm is approximately equal to 0.5512 inches.

What drill is used to tap a 1/14 hole? A 1/14 hole size is not a standard thread size. It appears to be a non-standard or custom thread designation. To determine the tap drill size for such a hole, you would need more specific information about the thread standard.

What is the diameter of 3/8 NPT? The diameter of a 3/8 NPT (National Pipe Taper) thread is approximately 0.675 inches or about 17.15mm.

What does NPT stand for? NPT stands for National Pipe Taper. It’s a standard for tapered threads commonly used in the United States for pipe fittings and connections.

What size drill for a 1/2-28 tap? For a 1/2-28 tap, you can use a drill bit with a diameter of approximately 27/64 inch or around 10.7mm.

What diameter is a 1/4-20 tap? A 1/4-20 tap has a major diameter of approximately 1/4 inch or 0.25 inches (6.35mm).

What bit for a 1/4-20 tap? To estimate the tap drill size for a 1/4-20 tap, you can use a drill bit with a diameter of around #7 or about 0.201 inches (5.11mm).

What is the rule of thumb for thread depth? The rule of thumb for thread depth is that the depth of the threaded portion should be at least 1.5 times the major diameter of the thread for most applications. However, specific requirements may vary.

Do you need to ream before tapping? In many cases, reaming is not necessary before tapping. A properly drilled hole should be sufficient for tapping. However, reaming may be used in precision applications to achieve a more precise hole diameter.

Do plumbers drill tap holes? Plumbers typically use a drill or hole saw to create openings for pipes and fittings in plumbing installations. They may also use taps for threading pipe ends, but the drilling and tapping processes are separate.

How do you drill and tap a 1/4-20 hole? To drill and tap a 1/4-20 hole, follow these steps:

1. Choose a drill bit size (approximately #7 or 0.201 inches) and drill a hole to the desired depth.
2. Insert the 1/4-20 tap into the hole.
3. Use a tap wrench or handle to turn the tap clockwise to create threads in the hole.
4. Apply cutting oil or lubricant to ease the tapping process.
5. Keep the tap perpendicular to the surface as you turn it.
6. Once the threads are formed, remove the tap, and your 1/4-20 threaded hole is ready.

What size hole for a 1/4-20 threaded insert? For a 1/4-20 threaded insert, you can use a drill bit with a diameter of approximately #7 or 0.201 inches (5.11mm).

Do I need a 1/4 or 1/2 drill? The choice between a 1/4 and 1/2 drill depends on your specific application and the size of the hole you need to create. If you need a 1/4-inch hole, use a 1/4 drill bit. If you need a larger hole, use a 1/2 drill bit. The size of the drill bit should match the desired hole size.

Why is it necessary to drill the correct tapping size? Drilling the correct tapping size is essential because it ensures that the threads will be properly formed and that the fastener (bolt or screw) will engage securely in the material. Using the wrong size can result in weak threads, difficulty in threading, or a loose connection.

What if you drill a hole too big? If you drill a hole too big for your intended fastener or threading, you may need to use a larger fastener or insert a bushing or sleeve to reduce the hole diameter to the appropriate size. Alternatively, you could use a larger tap and fastener if available.

What happens when a drilled hole is larger than needed for a tapping operation? When a drilled hole is larger than needed for tapping, it can result in loose or weak threads, reduced holding capacity, and decreased fastener strength. To address this, you may need to use a larger tap, insert a threaded insert, or employ a larger fastener to achieve a secure connection.