NDFFits and Tolerances
Privacy Policy

iOS, iPadOS & Android app

Fits and Tolerances – Support

Support for the technical reference tool for looking up hole and shaft tolerances and calculating fits according to ISO 286-2, for nominal sizes up to 3,150 mm.

Last updated: August 11, 2026

Contact support

Support provider: NDF

Email: contact@ndfamily.net

Expected response time: 2–5 business days.

What we can help with

  • Calculation error reports.
  • Interface or display issues.
  • Feedback about tolerance and fit data.
  • Privacy support requests.
  • Feature suggestions.

Never send passwords, verification codes or payment information in a support request.

Before reporting an issue

To help us investigate, please include:

  • App version.
  • iOS, iPadOS or Android version.
  • Device model.
  • The nominal size and tolerance zone you entered.
  • A screenshot, if available. Please remove personal or sensitive information first.

Technical reference notice

Fits and Tolerances is a technical reference tool. Before manufacturing, inspection or acceptance, users must verify results against the applicable standard, drawing and technical requirements. The app is not certified or endorsed by ISO.

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Send a support request / Gửi yêu cầu hỗ trợ

You may use this form or email contact@ndfamily.net directly. / Bạn có thể dùng biểu mẫu này hoặc gửi email trực tiếp.