The Starrett C11H-12-4R combination square’s model suffix is useful purchasing information. Its published 4R graduations are inch fractions, so a woodworking buyer should not infer a millimetre scale from a familiar tool shape or from a shop’s broad “metric/imperial” category.

This guide interprets the manufacturer’s UK listing, checked on 14 October 2026. It is a product-identity and specification guide, not a calibration test, a machining instruction or an assessment of a particular used tool.

Preserve both identifiers

Starrett’s C11H-12-4R listing gives the UK item number BH222 and global item number C11H-12-4R. It lists a 12-inch size and 4R graduations of eighths, sixteenths, quick-reading thirty-seconds and sixty-fourths, with a satin-chrome blade. These are the fields to compare with an offer for this exact item.

Match the scale to the drawings you actually use

Start with a sample of the plans or dimension records used in the workshop. Identify their units and the way dimensions are expressed. A tool can have an appropriate physical size while presenting a scale that does not match the user’s normal notation.

For a buyer following fractional-inch plans, the stated graduation pattern is directly relevant. A buyer working primarily from millimetre drawings should research a specifically documented scale instead of treating this listing as evidence of one. This is a purchasing distinction, not a claim that either measurement system is better.

Ask for an identity photograph, not an accuracy verdict

A clear photograph of the offered tool’s markings can help resolve which model and scale are being sold. It cannot demonstrate calibration or prove the condition of an entire used tool. Keep those different purposes visible when requesting information from a seller.

For a second-hand purchase, ask for the complete included-item list and describe any condition evidence you need separately. Do not translate “Starrett” or “precision tool” into an unsupported tolerance claim. We have not inspected a sample, measured its geometry or evaluated its readability.

Keep regional naming without assuming regional supply

The UK item number is valuable when communicating with a UK supplier. The global item number provides another identity field for comparing documentation. Neither number establishes stock, delivery time or support terms from a seller in another country.

Request a dated quotation with the exact identifier and reject an unspecified substitution until its scale and contents are documented. A similar-looking combination square may answer a different requirement. Comparisons should preserve the required graduation pattern rather than selecting an alternative by brand and length alone.

The narrow conclusion

This listing establishes a fractional-inch 4R pattern for the named model. It does not establish a millimetre scale, the condition of an offered unit or the suitability of the tool for a safety-critical task. The useful outcome is a more precise enquiry tied to the actual drawings and model.

Explore other workshop purchasing questions at Oodworking. Keep the source date, global code and required scale together before accepting a supplier’s description.