DIN 8140 is the standard cited for thread insert installation tools. This page sets out what the standard controls for this part, reproduces the dimensional table supplied against it, and notes the related designations referenced on drawings.
DIN 8140 — Scope
The table below lists the dimensions catalogued for thread insert installation tools under DIN 8140. The scope of DIN 8140 itself is not summarised here — where a figure matters, confirm it against the published document.
Tolerance & Product Grades
Product grade is a concept from dimensional fastener standards and does not apply to DIN 8140. Tolerances for this part are the limits shown against each dimension in the table.
Dimensions Specified by DIN 8140
| Tool | Step in the sequence | Sized by | Notes |
|---|---|---|---|
| STI tap | cuts the oversize thread for the insert | insert thread size | not the same as an ordinary tap of that size |
| insertion mandrel / tool | winds the insert to depth | insert thread size | sets the insert one half-pitch below the face |
| tang break-off punch | removes the driving tang | insert thread size | the tang must be removed and retrieved |
| extraction tool | removes a failed insert | insert thread size | for rework |
| key-locking insert tool | drives the keys into the parent metal | insert thread size | for key-locking inserts, not wire inserts |
Companion Standards
A complete specification for thread insert installation tools normally cites several documents: one for the geometry, one for the material or mechanical properties, and one for the finish. DIN 8140 is one of them, not all of them.
When to Specify DIN 8140
DIN 8140 is still widely used in European mechanical engineering and as a cross-reference on legacy drawings; its ISO equivalent is preferred for new designs.
Custom manufacturing · Made to drawing
Need a fastener tool to this standard in a non-standard size?
Parts built to DIN 8140 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
