Thread tapping is a crucial manufacturing method where a thread tap creates threaded parts in metal fasteners. This is commonly seen in industries like automotive and medical, where threaded holes hold parts together, making them more compact and convenient for transportation and use.
Machinists and engineers employ various types of taps, and selecting the right one is vital for the project’s success. In this article, we’ll break down what a thread tap is, explain how to use it for threading, and discuss the factors to consider when choosing the appropriate tap for the job.

Thread Tap

A thread tap is a special tool that helps create threaded holes in metal parts. It’s like a magic wand for metalworkers! This tool is used after a hole is drilled in the metal. The tap comes in different shapes and sizes, and you can use it by turning it with your hands or a machine. These taps are often made from tough materials like hardened chrome steel, solid carbide, or high-speed steel. They are like superheroes that give metal parts their special threads. The threads are like the tiny ridges on screws, and they help hold parts together when regular bolts and nuts won’t do the trick. So, think of a thread tap as a helpful tool that adds these special twists to metal holes, making them perfect for connecting different parts!

Types Of Taps

Various types of taps are designed for cutting different thread types in holes. The following outlines these taps and their unique characteristics:
  1. Hand Taps: The complete set of hand taps consists of the taper tap, plug tap and bottoming tap.
  2. Taper Tap: With 8-10 thread chamfers before the full cutting diameter, the taper tap is often used as a starter tap for blind holes in hard materials. It provides a gentle and gradual cutting motion but isn’t suitable as the sole tap for a project since it cannot thread to the bottom.
  3. Plug Tap : Following the taper tap, the plug tap is commonly used to give pre-drilled holes the desired depth and form. It has 3-5 threads tapering from the tip, offering a more forceful cutting action than the taper tap.
  4. Bottoming Tap : Used as the last tap in a project, the bottoming tap has 1-2 thread chamfers and does not align with the hole when starting the threading process. It cleans already-cut threads as it cuts.

Master Tap

Like the taper tap, the master tap differs in the number of flutes, featuring 7-10 flutes with more cutting faces. Master taps are useful for cutting clean threads in hard and strong materials.

Gas Tap

Designed for cutting gas-type threads for merging hydraulic fittings and pipes, the gas tap has 1-2 thread chamfers that work well with cylindrical and conical-shaped holes.

Machine Tap

Unlike the manual hand taps, the machine tap is fully automated, utilizing a tap drill machine. This reduces the risk of damage to the workpiece and the tap, streamlining the threading process with less manual labor.

Machine Screw Tap

Not fully automated, the machine screw tap can be used with either a manual tap handle or a tap drill machine. With 2-4 threads tapering from the tip, it can manually thread deep holes in various material types, suitable for repairs and routine maintenance.

Extension Tap

Like hand taps, extension taps have a long shank above the body, enabling them to reach inaccessible holes like those in the hub of a pulley.
In summary, mastering thread tapping, commonly used in many industries, is crucial for making threaded holes in metal parts. A thread tap is a special tool, like a magic wand for metalworkers, that adds twists to holes, making them perfect for connecting parts. There are different types of taps, from manual ones like taper and plug taps to automated ones like machine taps. Each tap has a specific job, and choosing the right one depends on factors like the material and the hole depth. This guide helps professionals understand and choose the right tap for successful manufacturing projects, ensuring metal parts fit together smoothly and securely.