A short label leaves questions open
A quotation such as “diameter × length” is incomplete unless the supplier defines what was measured. Separate thread diameter, pitch, length, head diameter and drive style. Ask whether the stated length includes the head and request a drawing when that convention is unclear.
Dimensional worksheet
| Feature | Buyer question |
|---|---|
| Thread | What diameter and pitch are offered? |
| Length | Which start and end points define this value? |
| Head | What diameter, profile and drive are supplied? |
| Application | Which frame component and reference sample apply? |
| Finish | What material, coating or locking feature is specified? |
Catalogs may provide diameter, length and head fields separately. That is useful identification evidence, not proof of compatibility with every frame using a similar nominal size.
Compare a sample without forcing it
For a damaged or unknown thread, do not infer pitch solely from an outside diameter measurement. Ask a qualified repair technician or the frame supplier to identify the thread using an appropriate reference. A part that starts to enter but binds is not an accepted match.
Record the measuring method and the supplier's tolerances. Do not publish a universal screw size chart assembled from unrelated SKUs. Keep any supplier drawing attached to the approved part number so a later order cannot silently change the head or length convention.