Thread type: UNS Unified National Thread Series ANSI B1.1

American thread with special pitch

The thread shown in the UNS thread table belongs to the American Unified National Thread Series (UTS). This collection of thread standards is defined and monitored by the American National Standards Institute (ANSI). The specifications in the UNS thread table follow the ANSI B1.1 standard.

The UNS is a thread with a special pitch. This means that the UNS thread table contains combinations of pitch and diameter that cannot be found in any other thread standard. The UNS thread has a flank angle of 60°. It is primarily used in the USA, Great Britain, Australia and New Zealand.

Based on the thread table for the UNS thread, you can see that UNS threads in many cases have more threads per inch than the comparable sizes of the UNF or UNEF thread standards. For this reason, screw connections made with UNS threads are particularly resilient and the strongest of the thread types belonging to the UTS. Threads with dimensions according to the UNS thread table are therefore often used in areas where the threads are exposed to high loads, for example for the spindles of machine tools or for spindles in the automotive industry.

As you can see from the UNS thread table, the thread designation consists of three components: First is the abbreviation UNS, followed by the outside diameter in inches and the number of threads per inch. As the various sizes in the UNS thread table are characterized by their unique combination of pitch and diameter, these two details are particularly relevant here. In our UNS thread table you will find thread sizes from 1/4" outside diameter up to 1" outside diameter. The number of threads per inch ranges from 14 to 40. We have also converted the outside diameter into mm so that you can use our UNS thread table easily even if you are used to working with metric data. You can also read the pitch in mm from the UNS thread table.

   Major Diameter inch  Major Diameter mmTPIPitch P in mm
UNS 1/4" - 240,2506,350241,058
UNS 1/4" - 360,2506,350360,706
UNS 1/4" - 400,2506,350400,635
UNS 3/8" - 270,3759,525270,941
UNS 7/16" - 240,43811,112241,058
UNS 1/2" - 240,50012,700241,058
UNS 5/8" - 270,62515,875270,941
UNS 3/4" - 240,75019,050241,058
UNS 7/8" - 180,87522,225181,411
UNS 1" - 141,00025,400141,814
Cross section of a UNS thread