Product and application brief
A taper pin has a body that gradually changes diameter along its locating length. This distinguishes it from a straight parallel dowel pin. Identify the selected taper, the diameter reference position and the mating-hole geometry together; a diameter and length without that context can describe different parts.
Product forms and reference names
| Product form / field | Reference and distinguishing details |
|---|---|
| Plain unhardened taper pin — ISO 2339 | ISO 2339:1986 identifies the unhardened taper-pin family. State the selected form and end requirements; plain pins do not automatically include an extraction thread. |
| Internal-thread taper pin — ISO 8736 | ISO 8736:1986 identifies unhardened taper pins with an internal thread. Provide the thread designation, location and usable depth as well as tapered-body dimensions. |
| External-thread taper pin — ISO 8737 | ISO 8737:1986 identifies unhardened taper pins with an external thread. Distinguish the threaded extension from the tapered locating body when stating lengths. |
| Maker references and drawing-defined pins | Bossard BN 861 describes a ground, unhardened ISO 2339 A catalogue form and cross-references DIN 1. Such catalogue associations are not proof that every DIN/ISO variant is interchangeable or that FastenerBridge supplies that brand. |
Taper and the diameter datum
The small-end and large-end diameters must relate to the same defined locating length. State whether a drawing specifies a taper ratio, angle or end diameters, and identify the reference position used for the nominal diameter. Do not transfer a taper from an inch-series or another standard solely because both products are called taper pins.
Plain and threaded end forms
Plain-ended, internally threaded and externally threaded versions are distinct constructions. A thread feature changes the identification and access requirements; it should not be added or removed by assumption. Provide thread and end details on the part or assembly drawing.
Mating-hole and assembly information
Provide the mating-hole taper, depth and through/blind arrangement, plus the locating position in the assembly. The pin drawing alone does not define the complete joint. Installation tools, preparation and any retaining arrangement remain assembly-specific; this page does not prescribe them.
Material condition and reference boundaries
The three ISO identities above concern unhardened taper-pin families. Do not treat a smooth ground appearance as evidence of hardening. Full standard tables, dimensional tolerances and national-standard equivalence are not verified here; confirm them against the exact specification before substituting a part.
Specification fields
| Product form / field | Reference and distinguishing details |
|---|---|
| Identity and form | Exact standard/edition, maker part number or controlled drawing; plain, internal-thread or external-thread construction. |
| Taper definition | Required taper ratio or angle, or drawing-defined end diameters and associated locating length; identify the diameter datum. |
| Diameters and lengths | Small-end and large-end diameters, nominal-diameter reference position, locating-body length and overall length; separate threaded extension where present. |
| End and thread details | Chamfer/radius and other end features; thread designation, position, usable depth or external threaded length if required. |
| Material and condition | Exact material designation, required condition and finish, with inspection requirements stated separately. |
| Mating holes | Taper, depth, through/blind arrangement and assembly drawing; identify any application-specific retaining detail. |
| Quantity and documents | Quantity in pieces for each form/size, drawing revision, inspection/traceability and marking or packing requirements. |
Common product questions
Is a taper pin the same as a straight dowel pin?
No. A taper pin changes diameter along its locating body; a straight parallel dowel has a parallel body. Similar names or one nominal diameter do not establish the same geometry.
Are ISO 2339, ISO 8736 and ISO 8737 interchangeable?
Not by reference number alone. Their identities distinguish plain taper pins from internal-thread and external-thread unhardened forms. Compare the exact geometry, material and assembly requirements.
Is a diameter and length enough to identify a taper pin?
Not always. State the selected taper, the diameter reference position, relevant lengths and end/thread construction, with the mating-hole drawing when available.
Related specification resources
Product references
References checked 6 October 2026 explain product identity. Third-party model names and approvals are not FastenerBridge brand affiliation, stock or certification claims. Final geometry and requirements follow the selected specification.