Screw taps for UN threads with special pitch ANSI B1.1

UN – American Thread with Special Pitch

UN threads refer to a range of American inch-based threads with a fixed pitch. Normally, you know it from thread tables that each thread size has a different thread pitch. However, with UN threads, the pitch remains consistently the same – at 8, 12, 16 or more threads per inch. This results in combinations of outside diameter and pitch that are not covered by the common American thread types UNC, UNF, and UNEF.

Everything You Need to Know About the UN Thread (ANSI/ASME B1.1) of the Unified Thread Series

The UN threads with a fixed pitch are mainly used to increase the variety of diameter and pitch combinations. There are a number of special pitch thread standards, the most common among them being 8, 12, or 16 TPI (threads per inch).

As a rule, the tables of UN threads with fixed pitch only include combinations not already covered by UNC, UNF, or UNEF. They are therefore meant as a supplement, not a replacement for the most commonly used thread standards in the USA. UN threads with fixed pitch otherwise share the features of other Unified Thread Standard (UTS) types, such as the 60° flank angle.

The thread designation indicates the pitch using an abbreviation. 8-UN stands for 8 threads per inch, 12-UN for 12, and so on. This is preceded by the outer diameter in inches, e.g., 1 3/8″ – 8-UN, 3/4″ – 12-UN, 1/2″ - 16-UN, or 5/8″ - 16-UN. Unlike other UTS thread standards, there are no fixed numerical values assigned to thread sizes here.

UN Threads – Our Product Range

In the BAER online shop you will find threading tools for UN threads with 8, 12, and 16 threads per inch. All of our taps and dies are made from high-quality base materials and manufactured with the utmost care to ensure frustration-free work and optimal results.

8-UN Taps and Dies (8 Threads per Inch)

To produce 8-UN internal threads, we offer you both hand taps and machine taps. Hand taps can be purchased individually or as a two-piece set consisting of a pre-cutter and finishing cutter. The tools are made of ground high-speed steel HSSG and are suitable for blind and through holes. Our 8-UN machine taps can also be used for both blind and through holes. Form C with straight flutes is ideal for most standard applications and offers flexibility.

To create external threads, you can use our 8-UN dies. The round version made from high-quality high-speed steel can be used either by hand with a die holder or in a machine. The 8-UN hex dies are especially versatile as they can be used with a standard ring or open-end wrench. This allows you to reach remote areas and carry out quick repairs without having to remove a component.

12-UN Taps and Dies (12 Threads per Inch)

We also offer the right tools for UN threads with 12 threads per inch. You can easily create internal threads by hand using our 12-UN hand taps. To make your work easier, cutting the thread is divided into three tools: pre-cutter, intermediate cutter, and finishing cutter. You can purchase each tap individually or as a convenient three-piece set. Our Form C machine taps for 12-UN threads are made of ground high-speed steel and provide excellent results across a wide range of materials.

To cut external threads, we offer round dies for 12-UN threads. When used with a die holder, you can easily create 12-UN threads by hand, but machine use with a compatible die adapter is also no problem.

16-UN Taps and Dies (16 Threads per Inch)

For working with 16-UN internal threads, our online shop offers taps for both manual and machine use. Our hand taps are available in convenient two-piece sets consisting of pre-cutter and finishing cutter. This way, you have all the necessary tools at once. The Form C machine taps with straight flutes are suitable for blind and through holes in many standard applications. All taps are made from ground HSS high-speed steel to ensure optimal results.

For 16-UN external threads, we offer round dies that are ideal for both manual and machine use.

Discover Tools and Accessories for UN (Unified National) Threads in the BAER Online Shop!

Browse through our product pages and explore our range. BAER stands not only for top quality and precision manufacturing – customer satisfaction is also especially important to us. For all your questions and concerns, our friendly customer service is always at your disposal – reachable by phone or via our contact form.