About MetricMech.
MetricMech is a free engineering reference for working manufacturing quality and production engineers. Decision-grade calculators, deep GD&T pages, standards explainers, and FAI/PPAP templates — built by people who have spent careers on shop floors and audit rooms.
What MetricMech is
The site exists because most engineering calculator sites fall into one of three groups: paywalled enterprise tools that small shops cannot afford, ad-heavy aggregators with calculation errors, or single-purpose calculators that do not show how to use the result. MetricMech is intentionally none of those.
32 calculators
Each one produces an interpretation, a tier-aware verdict, and an audit-ready PDF report — not just a number.
Deep references
GD&T symbol pages, standards explainers (AS9102, ISO 286, ASME Y14.5), and step-by-step articles for FAI and PPAP submissions.
Free templates
Downloadable AS9102 forms, PPAP element packs, control plans, FMEA worksheets — used by Tier-2 and Tier-3 suppliers across India.
Always free
No signups, no paywalls, no ads. The site is funded by CadNexa, not advertisers.
Who runs this site
MetricMech is run by Rajadurai R, a mechanical engineer with experience in plant operations and the founder of CadNexa. The technical reviewers and authors who contribute articles are practising QA, production, and aerospace engineers — most based in India, working with Tata, Mahindra, Bajaj, TASL, and Bharat Forge supply chains.
Author bylines appear on every article. Articles are drafted by an engineer or AI-assisted with engineer review, and every piece is grounded in citeable standards before publication — see the editorial standards for the review process and source policy.
How content is created and reviewed
Every page on MetricMech follows a four-step process:
- Source anchoring. Each topic is mapped to a specific published standard or specification — ASME Y14.5 for GD&T, AS9102 Rev C for aerospace FAI, ISO 286 for fits, etc.
- Drafting. First draft is produced by an engineer or AI-assisted with engineer prompts. Formulas, citations, and worked examples are verified against the source standard.
- Review. Reviewed by a working engineer for technical accuracy, real-world relevance, and tone.
- Publish + monitor. Published with the author byline, the publication date, and the standards referenced. Corrections are logged and the page is re-dated.
What MetricMech is not
- Not a replacement for the actual standards. If a regulator or auditor asks what controls your inspection process, the answer is "ASME Y14.5-2018 and AS9102 Rev C", not "the MetricMech page on position tolerance".
- Not a content farm. Pages are added at ~3/week, deeply researched and reviewed, not churned out by the hundreds.
- Not a substitute for engineering judgement. Calculators and references inform decisions. They do not make decisions. Use them as part of an informed workflow.
Open source
The MetricMech site code is open source on GitHub — see github.com/mechsterrd-maker/metricmech. If you find a calculation error, an outdated standards reference, or a broken link, file an issue or contact us at the contact page.
Contact and feedback
Topic suggestions, calculation reports, and reviewer applications are welcome. See the contact page for the right channel.