A HANDBOOK FOR SHOP LENGTH CHECKS
A gauge block
is a check.
Not a certificate.
How a small workshop records a 0–25 mm micrometer or digital caliper against known blocks — and what that record still is not.
Source-led notes for UK model engineers, incoming inspection and small machine shops. MeasureProof is not a UKAS laboratory.
WHAT THIS SITE DOES
Explain the shop check.
Stop at the evidence.
These notes interpret published workshop methods and UK metrology guidance.
No original gauge-block series by this publication is included.
Workshop
notes
Repeats, mid-range checks, and why zero plus full scale is not enough.
Open the workshop notes ↗02 / THE DISTINCTIONThree kinds
of document
Shop check, manufacturer inspection and a UKAS certificate.
Read the methods ↗03 / THE RELATIONSHIPRelated
retail shops
accumeasure.co.uk and proster.co.uk are commercially related.
Read the disclosure ↗START WITH THESE NOTES
Keep the columns apart.
Checking a 0–25 mm micrometer with gauge blocks
What a workshop record of repeats on known blocks can show, and why it is still not a UKAS certificate.
8 MIN READ ↗Source-based noteZero and full scale is not enough
Why a zero setting plus one full-range block can miss mid-travel error, using Sparber’s published inch table as the example.
7 MIN READ ↗Source-based noteCaliper outside, inside and depth are different checks
An outside-jaw reading on a gauge block does not pass the inside jaws or the depth rod. Keep the three faces in separate columns.
8 MIN READ ↗READ THE CLAIM. SEE THE SOURCE.
A stated ±0.02 mm is still only a statement.
Display resolution, a manufacturer specification and the scatter of a real check are three different numbers. This edition publishes explanations and a blank record. It does not publish original repeats from this publication.