Torque wrenches: explain what a calibration certificate covers
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- Last reviewed
A calibration certificate is useful only when the buyer can connect it to the torque wrench being sold and understand what it reports. A certificate in the same case is not enough.
Check the tool's manufacturer, model and serial number against the document. Preserve the full report rather than extracting a date or logo for the catalogue. If the identity does not match, treat the certificate as unresolved evidence until the discrepancy is explained.
A document-matching example
Suppose an inventory contains wrench TW-A and a certificate bearing identifier TW-B. The tools appear similar, but there is no record connecting the identifiers. The correct catalogue note is that a document is available whose match has not been established. It is not “calibrated wrench with certificate”. These identifiers are illustrative, not a real sale case.
Use the following check for each instrument:
| Check | Evidence to retain |
|---|---|
| Identity | Tool markings and matching certificate identifier |
| Date | Date stated by the laboratory, kept distinct from any later label |
| Scope | Measurement points, range and other qualifications actually reported |
| Findings | Results and any stated limitations, without selective extraction |
| Later history | Known use, repairs, damage or other events after the report |
| Unresolved issue | Question for the laboratory, manufacturer or competent adviser |
Do not invent a universal period for which a certificate is “valid”. The document's date, a user's review arrangements and present suitability are separate matters. If an expiry or next-review statement appears, preserve its source and wording rather than treating it as a rule for every wrench.
Explain what the buyer receives
A useful description names the instrument, identifies the available report and states its date. It can then direct the buyer to the complete document, subject to an appropriate sharing arrangement. Avoid “guaranteed accurate” or “fully certified” when those claims go beyond the evidence.
UKAS's metrology information explains the role of accreditation in measurement services. An accreditation reference still needs to be considered against the laboratory and scope involved; it does not remove the need to match the actual tool and report.
Keep electrical test-meter records, micrometer and gauge sets and coordinate-measuring machine evidence in their own files. Their measurement scopes are different, even where the document-matching principle is similar.
For valuation, send UK Auction Group photographs of the wrench identity, the complete available report and its later history. State any missing or mismatched evidence before asking how the item should be described or grouped.
Explore the workshops and tools guides.
Sources
- UK Auction Group: valuations Checked
- UKAS: metrology sector accreditation Checked
This guide gives general information. Equipment-specific, legal, tax and safety decisions may need a qualified adviser or competent specialist. The guides do not promise sale prices, fees or results.