Plain Gage Tolerance Calculator
Enter the smallest and largest acceptable size of a hole or shaft. Get the gage class to use, the GO and NO GO gage sizes, and the plug or ring gages that check them.
How these numbers are calculated
Gage class: ASME B89.1.5 gagemaker's tolerance classes XXX (tightest) to ZZ (loosest), by diameter band. The suggested class is the loosest one whose tolerance is no more than 10% of the part tolerance per gage (or 5%, if you choose the stricter rule). Looser classes cost less; a tighter class always works.
GO / NO GO sizes: the GO gage is made to the part's maximum-material limit (smallest hole, largest shaft) and the NO GO gage to the least-material limit. Gage tolerance is applied inside the part limits: plus on a GO plug, minus on a NO GO plug, and the reverse for rings.
Thread gages? Use the Thread Gage Finder. For anything outside the standard, call 1-888-400-4243.
Disclaimer
This calculator is a reference tool. Results are calculated from published ASME and ISO formulas and tables, but they are not a substitute for the applicable standard, your drawing or your customer's requirements.
You are solely responsible for checking every value before you use it to make, buy, inspect or accept parts or gages. WESTport Corporation provides this tool "as is" and makes no warranty, express or implied, as to the accuracy, completeness or fitness for a particular purpose of any result. WESTport is not liable for any loss, damage, scrap, rework or other cost arising from the use of, or reliance on, this tool.
For certified gage dimensions, or if you're unsure which gage you need, call 1-888-400-4243.