Product and application brief
Dowel pins are straight, headless locating parts used to align mating components. Their parallel body differs from a taper pin, while a solid dowel differs from a slotted or coiled spring pin. Nominal diameter alone does not define the assembly fit: the pin requirements and each mating hole need their own specification.
Product forms and reference names
| Product form / field | Reference and distinguishing details |
|---|---|
| Unhardened parallel pin — ISO 2338 reference | ISO 2338:1997 identifies the unhardened steel and austenitic stainless family. Specify material and the selected dimensional requirements rather than treating every smooth pin as hardened. |
| Hardened parallel pin — ISO 8734 reference | ISO 8734:1997 identifies the hardened steel and martensitic stainless family. Material, heat treatment and end geometry must follow the chosen specification; the illustration does not certify them. |
| Internal-thread parallel pin — ISO 8735 reference | ISO 8735:1997 identifies the internally threaded hardened steel and martensitic stainless family. A threaded end is a distinct feature; it is not present on every plain solid dowel. |
| Drawing-defined locating pin | Supply the controlled drawing for nonstandard end forms, stepped sections, special lengths or other changes. A maker part number or familiar name does not establish interchangeability. |
Parallel body and end details
Check straight cylindrical body, overall length and both end forms. Horberg describes a straight, headless metric construction with radius and chamfer details; that maker description is an identification example, not a universal drawing for every dowel.
Pin fit and mating holes
State the pin diameter tolerance separately from the hole diameter, tolerance and depth in each component. Identify through or blind holes and the intended locating arrangement on the assembly drawing. This page does not prescribe a universal fit pair or installation procedure.
Internal thread and removal access
If an internally threaded end is required, identify its thread designation, usable depth and location, along with assembly access. Do not substitute an ordinary solid-ended pin where a threaded-end construction is specified. Tooling and installation details remain assembly-specific.
Reference names are not compliance evidence
The ISO references distinguish product families; they do not demonstrate that a quoted part complies. Full normative dimensions, tolerances, hardness requirements and national-standard interchangeability have not been verified here. Confirm the exact document, edition and drawing requirements before selecting a replacement.
Specification fields
| Product form / field | Reference and distinguishing details |
|---|---|
| Product identity | Plain parallel dowel, internally threaded parallel pin, or drawing-defined construction; exact standard and edition or manufacturer part number. |
| Diameter and tolerance | Nominal pin diameter, its tolerance requirement and measurement/inspection basis. Keep pin and mating-hole requirements separate. |
| Length and ends | Overall length, usable locating portion, chamfer or radius at each end, and drawing-defined features where applicable. |
| Internal thread, if present | Thread designation, position and usable thread depth; do not add a threaded-end requirement to a plain pin by assumption. |
| Material and condition | Exact material designation and required hardened or unhardened condition; stainless family alone is insufficient to identify the part. |
| Mating-component details | Hole dimensions, tolerances and depths, blind/through arrangement and relevant assembly drawing. |
| Surface and inspection | Required finish, surface requirements and inspection/traceability documents, without assuming a coating is compatible with the specified fit. |
| Quantity and identification | Quantity in pieces, separate line items for sizes/forms, controlled drawing revision and packaging or marking requirements. |
Common product questions
Are ISO 2338 and ISO 8734 dowels the same product?
No. The official identities distinguish unhardened and hardened material families. A matching nominal diameter and length is not sufficient evidence of substitution; compare the selected specification and assembly requirements.
Does every dowel pin have an internal thread?
No. ISO 8735 is an internally threaded parallel-pin reference. Plain-ended pins and internally threaded forms should be identified separately in a parts list.
Can a pin diameter specify the fit by itself?
No. Pin tolerance and the dimensions, tolerances and depths of the mating holes are separate requirements. Provide the assembly drawing rather than relying on a universal fit assumption.
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.