Types of Thread Taps – A Simple Guide

What Are Thread Taps?

Thread taps are tools that make threads in holes. These threads let you put screws or bolts in the holes. You need the right tap for your job.

There are three main types of thread taps that most people use:

• Plug taps for most jobs
• Taper taps for starting new threads
• Bottoming taps for making threads all the way to the bottom of a hole

The tap you pick depends on your material, the hole type (blind or through), and the thread pitch you need.

Common Types of Thread Taps

Hand Taps

Hand taps are used with hand tools. You turn them by hand to make threads.

1. Plug Taps

Plug taps have a medium taper at the tip. This makes them good for most jobs. You can use them for both new threads and fixing old threads.

2. Taper Taps

Taper taps have a long, slow taper at the tip. This helps them start threads easily in new holes. The taper goes across 8-10 threads.

3. Bottoming Taps

Bottoming taps have almost no taper. They are used to make threads all the way to the bottom of a blind hole. You should use a taper tap first, then the bottoming tap.

Machine Taps

Machine taps are made for use in machines like CNC mills and drill presses. They work faster than hand taps.

They are often made of HSS (High Speed Steel) or have TiN-coating (Titanium Nitride) to last longer.

Pipe Taps

Pipe taps are special taps for making threads in pipes. They make NPT threads or NPTF threads that are used in plumbing and air systems.

Special Thread Taps for Hard Jobs

1. Spiral Flute Taps

Spiral flute taps have grooves that spiral up the tap. This helps push chips up and out of the hole.

• Best for: Blind holes where chips can’t fall through
• Good with: Aluminum and other soft metals

2. Spiral Point Taps

Spiral point taps (also called gun taps) have a special point that pushes chips forward through the hole.

• Best for: Through-holes where chips can fall out the bottom
• Good for: Fast tapping jobs

3. Thread-Forming Taps

Thread-forming taps don’t cut the material. They push the material to make threads. This makes stronger threads and no chips.

• Best for: Copper, brass, and other soft metals
• Good because: No chips to clean up

4. Interrupted Thread Taps

Interrupted thread taps have gaps in the threads. This gives more room for chips to escape.

• Best for: Hard materials like stainless steel
• Good because: Less likely to break in tough materials

5. Combined Drill/Tap Tools

These tools both drill the hole and tap it in one step.

• Best for: Small holes (M3-M10)
• Good because: Saves time by doing two jobs at once

How to Pick the Right Tap

Picking the right tap can be hard. Here’s how to choose:

Material Matters

• For hard alloys like stainless steel: Use solid carbide or interrupted thread taps
• For soft metals like aluminum: Use spiral flute or thread-forming taps

Hole Type

• For blind holes (holes with a bottom): Use bottoming taps and spiral flutes
• For through-holes (holes that go all the way through): Use spiral point taps

Thread Standards

Make sure you know if you need:

• Metric threads (like M8, M10)
• Imperial threads (like 1/4-20, 3/8-16)
• NPT threads for pipes
• BSP threads for British pipe standards

Thread Pitch

• Fine threads: More precise, stronger in hard materials
• Coarse threads: Easier to tap, better in soft materials

Tap Types Comparison Table

Best Practices for Using Taps

Use the Right Lubricant

Always use cutting oil when tapping metal. This:

• Keeps the tap cool
• Makes cutting easier
• Helps the tap last longer

Manage Your Chips

• Use spiral flute taps for blind holes
• Use spiral point taps for through-holes
• Back out the tap often to clear chips

Control Your Speed

Don’t go too fast when tapping. The right speed depends on:

• The material you’re tapping
• The tap type
• The size of the tap

Avoid Breaking Taps

• Make sure the tap is straight
• Don’t push too hard
• Use “peck tapping” (in and out) for deep holes

Common Mistakes to Avoid

1. Using a taper tap in a blind hole and not finishing with a bottoming tap
2. Forgetting to clear chips, which can cause the tap to break
3. Using metric taps in imperial holes or the wrong way around
4. Not using lubricant when tapping hard steel

Data from Real-World Use

Studies show that picking the right tap makes a big difference:

• Spiral flute taps have 40% fewer breaks than straight flutes in aluminum 
• TiN-coated HSS taps last 50% longer in high-carbon steel than plain ones 
• 80% of tap breaks happen because the tap wasn’t lined up right 
• Thread-forming taps work in materials up to 36 HRC hardness with no chips
• Combined drill/tap tools can save 25% of time when making small holes

Questions People Often Ask

Wrap-Up

Picking the right thread tap helps you make good threads that last. Remember:

1. Match your tap to your material
2. Think about your hole type (blind or through)
3. Use the right lubricant
4. Go slow and be careful

For tough jobs with hard materials, try coated carbide taps. They cost more but last longer.

Want to learn more about for your projects? Our experts can help you choose the right tools and methods.

Also check out our guides on CNC thread milling for making perfect threads on CNC machines, and precision CNC machining when you need exactly the right fit.