Three related profiles are currently supported by the software : UN, UNR, and UNJ. The UNR and UNJ profiles specify rounded minor diameter roots for external threads. External UN and UNR threads have three tolerance classes, 1A, 2A, and 3A. UNJ threads have just 2A and 3A. Class 3A threads have no allowance, whereas 1A and 2A have allowances, in addition to larger tolerances. Correspondingly, internal threads come in classes 1B, 2B, and 3B. However, internal threads have no allowance.

References :
For UN, UNR and UNJ product threads, see ASME B1.1-2019. For gages, see ANSI/ASME B1.2-1983, except for UNJ minor diameters for GO Work Ring minor diameters, which are based on UNJ external minor diameters. The UNR designation only applies to external threads; this software shows internal dimensions for UN threads to mate with UNR external threads.

Tips on using this software

• Size Numbers: You can enter a nominal size with the # sign to specify some small sizes. For example, entering #5 is equivalent to entering 0.125 . The supported "jeweler's sizes" are currently #000, #00, #0, #1 through #14.
• There is an option to use H28-1969 for the maximum minor diameter of UN threads. Otherwise, B1.1-2019 is used.

Working Thread Rings are used to gage external product threads. The "GO" ring should assemble with the product it is gaging, whereas the "NOT GO" ring should not. Generally, the minimum major diameter is specified, without a tolerance.

Working Thread Plugs are used to gage internal product threads. The "GO" plug should assemble with the product it is gaging, whereas the "NOT GO" plug should not. Generally, the maximum minor diameter is specified, without a tolerance.

Setting Rings are used to set indicating gages for internal product threads. GO rings are used to set gages to the maximum material size, NOT GO for the minimum material size. Generally, the minimum major diameter is specified, without a tolerance.

Setting Plugs are used to set indicating gages for external product threads, in addition to adjustable working ring gages. GO plugs are used to set gages to the maximum material size, NOT GO for the minimum material size. Generally, the maximum minor diameter is specified, without a tolerance.