What Are Tap and Die Sets Used For?
Tap and die sets are essential tools in engineering and manufacturing, used primarily for cutting threads on the inside of a hole (tapping) and on the outside of a rod (dying). These tools allow workers to create precise screw threads, which are crucial for assembling parts that require a high degree of accuracy.
Taps are used to form the female portion of a mating pair, such as the internal threads of a nut or a threaded hole, while dies are used to create the male threads, like those on a bolt or a screw. This capability is particularly valuable in custom or repair work, where matching exact thread sizes and pitches can be critical for properly fitting and functioning mechanical components. Tap and die sets come in various sizes and thread patterns to accommodate different materials and thread requirements, making them versatile tools across industries.
Understanding Tap Specifications
Whether you're cutting new threads or repairing damaged ones, utilizing the correct hand tap for the job is essential to getting it done right. However, questions often arise when taking on the task, such as: How do you select a hand tap? What do all the numbers mean, such as 5/8 - 11 or M6 x 1.00? What do terms like taper, plug, or bottoming mean? With the correct information, it doesn’t have to be confusing.
Thread designations consist of two main specifications: diameter and pitch. Diameter is the distance across the face of a fastener or tap, while the pitch is a measurement of the actual threads. In the case of SAE threads, the pitch is a measurement of the number of threads per inch of length (TPI), while metric thread pitch is measured by the distance from the peak of one thread to the peak of the next thread in millimeters. See the images below for more detail.
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Three Main Types of Taps and Their Applications
Taper Tap: Also called starting taps, these taps have chamfered (tapered) ends for the first 8-10 threads, which distributes the cutting force over a larger area and seats the tap into the hole more easily. Taper taps are used to start threads in a new hole and are also good for tapping thin material.
Plug Tap: Also known as second taps, these have 3 to 4 chamfered threads at the lead end. The most popular tap, plug taps can be used as a second or starting tap. They’re commonly used on through holes and blind holes where threads are not required close to the bottom.
Bottoming Tap: This tap has 1 to 2 chamfered threads at the lead end and is used to produce threads as close as possible to the bottom of the hole. It must be preceded by a plug tap to work correctly.
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Whether you need a single hand tap or a tap set, Zoro has what you need with our selection of taps, punches, and dies in addition to tap wrenches to keep your job moving.
Product Compliance and Suitability
The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness, or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand, and follow all manufacturer instructions. Portions of this article were generated in part by ChatGPT, and edited by a member of the Zoro team.