How to Clarify a Missing Tolerance Before Pricing

A drawing can show a nominal size without a usable acceptance limit. If a tolerance affects machining, assembly or inspection, guessing a default can make a quote look comparable while hiding a different product. Identify the affected feature and ask for a decision before committing to the process.

Ask about the decision, not just the symbol

Point to the drawing revision, feature and dimension. Explain why the limit matters: it may change process choice, gauge method, scrap risk or fit with another part. Offer a concise question such as “What acceptance range should apply to this bore on revision C, and is the mating part drawing available?” Do not invent an industry-wide tolerance when the buyer's design is the authority.

If the buyer cannot answer immediately, give a clearly labelled provisional quotation assumption and exclude final tooling release until written confirmation. The assumption should appear beside the price, not buried in an email thread. The quotation owner should record who approved it and when.

An internal check is to have quality and production independently read the current drawing. If they interpret the critical feature differently, the ambiguity is still open. Resolve it before a sample is presented as proof of conformity.

Worked example (illustrative)

If a shaft drawing shows a nominal diameter but no usable acceptance range, the supplier can mark that feature on revision C and ask for the mating-part requirement. The response log keeps the question open, and the quote states a provisional assumption only if the buyer agrees. Nobody treats the assumption as a measured part specification.

Source check

Checked 2026-09-28. ISO geometrical-product-specifications committee scope covers dimensional and geometrical tolerancing and its verification. The linked source supports this point only. The steps and worked example above are editorial guidance; they do not establish any supplier’s capability or guarantee a buyer response, order or delivery.

Evidence and use boundary

Editorial method reviewed: 2026-09-27. This article is an operational checklist, not a report of current market conditions or a claim about any particular factory, buyer, certification or delivery result. Check the current product and transaction records before acting.