🔩 Use of Thread Gauge

A thread gauge is a tool used to check the size and pitch of a screw thread. It helps identify the type of thread on a bolt, screw, or nut.


🧰 What is a Thread Gauge?

A Thread Gauge (also called a screw pitch gauge) is a measuring tool with multiple blades or leaves, each having different thread profiles (like teeth).
These blades are used to match and measure the thread pitch on fasteners.


📌 Main Uses of a Thread Gauge

1. 📏 To Measure Thread Pitch

  • The most important use of a thread gauge is to measure thread pitch (the distance between two threads).

  • This is useful when you don't know what kind of bolt or screw you're working with.

2. 🔧 To Identify Thread Type

  • Helps to identify metric or imperial (inch) threads.

  • Allows the correct tool or replacement part to be selected.

3. 🧪 To Check Thread Accuracy

  • Used to verify if the threads are worn out or damaged.

  • Ensures fitting quality and safety in electrical and mechanical assemblies.

4. 🛠️ To Avoid Wrong Matches

  • Prevents using the wrong screw or bolt that may damage the threads or cause accidents.


🔍 How to Use a Thread Gauge?

  1. Select the blade that you think matches the thread.

  2. Place the blade into the thread of the bolt or screw.

  3. If the teeth fit perfectly into the thread grooves — it’s a match!

  4. Read the pitch number written on the blade (e.g., 1.25 mm, 20 TPI).


📘 Types of Thread Gauges

🔧 Type📋 Description
📐 Metric Thread GaugeMeasures threads in millimeters
🧮 Inch Thread GaugeMeasures threads in TPI (threads per inch)
📚 Combined GaugeHas both metric and inch scales

🧠 Example:

  • If a thread gauge blade marked “1.25 mm” fits a bolt, the thread pitch is 1.25 mm (i.e., distance between threads is 1.25 mm).

  • For inch threads, it might say "20 TPI" – meaning 20 threads per inch.


⚠️ Safety & Handling Tips

  • 🧤 Handle carefully – the blades are thin and sharp

  • 🛠️ Keep the gauge clean and rust-free

  • 📦 Store it in its protective case when not in use

  • 👀 Use proper lighting while measuring for better accuracy


💡 Conclusion

A Thread Gauge is a small but very useful tool in electrical, mechanical, and fitting work. It helps in correctly identifying threads, which is essential for safe and accurate assembly.

🔧 "Right thread = Tight fit!"