ISO 286 Fit & Tolerance Calculator (H7/g6, H7/p6…) Community
Questions, answers and tips from people who use the ISO 286 Fit & Tolerance Calculator (H7/g6, H7/p6…). Limits and fits for any size: hole/shaft deviations, clearance or interference.
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This page shows only real posts from real people, so it starts empty. The guide below has the questions people most often have about the ISO 286 Fit & Tolerance Calculator (H7/g6, H7/p6…). Pick one to start a thread, or write your own.
From the tool guide: common questions about ISO 286 Fit & Tolerance Calculator (H7/g6, H7/p6…)
The items below are not posts by community members. They come from the written guide for this tool and are here to get a conversation started. Use “Ask a follow-up” to open a thread about any of them.
What does H7/g6 mean?
A hole to H7 (lower deviation zero, IT7 tolerance) paired with a shaft to g6 (small negative deviation, IT6 tolerance) — a sliding clearance fit.
From the tool guide Ask a follow-upHow do I know if a fit is clearance or interference?
If the smallest hole is larger than the largest shaft it is clearance; if the largest hole is smaller than the smallest shaft it is interference; otherwise transition.
From the tool guide Ask a follow-upWhich sizes are covered?
0 to 500 mm. Letters r, s, t, u and larger grades are not included.
From the tool guide Ask a follow-upAre the numbers exact?
They reproduce the standard's tabulated values for the included letters and grades.
From the tool guide Ask a follow-upWhat this tool does
The ISO system of limits and fits describes how tightly a shaft sits in a hole using a letter for the fundamental deviation and a number for the tolerance grade — H7 for a hole, g6 for a shaft. This calculator turns that notation into numbers: enter a nominal size up to 500 mm and any hole/shaft pair (for example H7/g6 or K7/h6) and it returns the lower and upper limit of each part, the fit type (clearance, transition or interference), the minimum and maximum clearance or interference in micrometres, and a diagram of the two tolerance zones against the zero line.
How to use it, step by step
- Enter the nominal size in mm.
- Type the hole and shaft fits, or click a preferred fit.
- Read the limits and fit type.
- Dimension the drawing with the resulting limit sizes.
Tips from the guide
- Prefer the hole-basis system (H holes) — holes are harder to adjust than shafts.
- For 3D-printed parts ISO fits do not apply directly; use the print tolerance chart instead.
- Check the IT grade your process can hold: IT7 is typical for reaming/grinding, IT11 for general turning.
- Dimension with limit sizes or tolerance symbols, not both.
Common mistakes to avoid
- Mixing up hole and shaft letters (capital = hole, lowercase = shaft).
- Using grades the machine cannot hold.
- Forgetting sizes above 500 mm need different tables.
Who uses it
- Mechanical engineering students. Check homework fits and tolerance stack-ups.
- Machinists and designers. Choose bearing, pin and bushing fits.
- Makers designing press fits. Turn H7/p6 into real hole and shaft sizes.
How to ask a question people can answer
A good thread on the ISO 286 Fit & Tolerance Calculator (H7/g6, H7/p6…) saves everyone time. Start with a title that names the exact problem, such as the input you used, the result you expected and the result you got. A title like “Not working” is hard to answer, while a title with the specifics gets replies quickly.
- Say what you tried. List the steps you followed and any settings you changed, so replies do not repeat what you already did.
- Share a small example. A short sample input and the output you saw is worth more than a long description. Remove anything private first.
- Mention your setup. Your device, browser and whether you are on a phone or a computer can explain many odd results.
- One question per thread. Separate topics get clearer answers and are easier to find later with the search box above.
- Come back and reply. If a suggestion worked, say so and upvote it, and if you found the fix yourself, post it for the next person.
Community rules
Be kind, stay on topic and keep personal data out of your posts. Do not post adult, hateful or illegal content, advertising or repeated links. Every post is shown with its author’s username and date, and posts that break these rules can be hidden by moderators. This space is for help with the ISO 286 Fit & Tolerance Calculator (H7/g6, H7/p6…) and related tasks, and it is separate from the sitewide discussion forum where broader topics live.