Knurled Pins

Product detail · Updated 10 October 2026

Product and application brief

Knurled pins are solid cylindrical parts with repeated raised surface features in the retaining region. They are different from smooth dowels, longitudinal grooved pins and hollow spring pins. Choose the actual retention pattern and assembly function rather than selecting by nominal diameter alone.

Product forms and reference names

Choice or field	What to identify
Straight knurl	SPIROL KP200 is an original maker example with axial knurls over the body length. The series name identifies that maker construction, not a FastenerBridge model or an ISO equivalence.
Helical knurl	SPIROL KP300 uses a sloping knurl pattern. It is not a threaded screw: installation behaviour and allowable joint movement need separate review.
Headed knurled pin	SPIROL FH200 and FH300 illustrate headed straight and helical forms. Specify head geometry, under-head length and the intended stop or retained member.
Partial or positioned knurl	The maker's additional-options page distinguishes modified knurl length and axial location from full-length standard forms. Define the smooth regions and retaining region on a controlled drawing.

Knurl pattern and finished envelope

Record straight or helical pattern, pitch/profile, any required handedness and the finished knurled envelope separately from the smooth body diameter. Overall length alone does not specify the contact region. Other patterns require their own drawing identity and review; do not label every textured surface as the same pin.

Axial retention and rotation are different requirements

SPIROL distinguishes straight and helical knurls and notes that its helical form can rotate during insertion. Give the required resistance to pull-out and rotation separately, and state whether the installed pin or another component must move. This identification page does not supply a torque, push-out rating or universal recommendation.

Full-length versus positioned knurl

Identify knurl start and end from a named datum, engagement in each member and any smooth guiding or bearing length. If a mating component must rotate around a smooth region, provide its clearance and bearing specification. A positioned knurl is a drawing-defined option, not evidence that any requested configuration is already manufactured.

Drawing standard is not a pin product approval

ISO 13444:2012 concerns dimensioning and indication of knurling for general mechanical engineering; ISO lists it as confirmed in 2024. It does not establish a complete knurled-pin product specification or qualify an installed joint. A drawing citing it still needs the selected pattern, dimensions, tolerances and acceptance requirements.

Receiving hole and installation

Provide host material and condition, controlled hole geometry, wall section, blind/through depth and entry details. The original maker catalogue states that hole selection depends on engagement and host hardness. Obtain application-specific hole and installation requirements; no generic interference allowance, pressing force or equipment compatibility is asserted here.

Adjacent pin choices

Grooved pins have a distinct longitudinal groove construction; smooth dowels use their specified body/hole fit. Slotted and coiled spring pins have hollow spring structures. A shared diameter or similar photograph is not a substitution rule. Use the existing product pages to compare constructions before finalising the joint drawing.

Material, finish and order confirmation

Request the exact grade, heat treatment or hardness where required, coating and finished-condition inspection. Appearance does not prove material, corrosion resistance, production method or conformity. Supply feasibility, quantities, packing and delivery require quotation confirmation. Reuse, repeated installation and environmental suitability need separate approved evidence.

Specification fields

Choice or field	What to identify
Part identity	Knurled pin; selected maker/reference or drawing number and revision. Do not substitute a grooved or spring-pin standard.
Pattern	Straight/helical, pitch/profile, handedness if relevant and drawing indication basis.
Body and knurled region	Smooth diameter, finished knurl envelope, axial start/end and required tolerances.
Head and ends	Headed/headless, head geometry, length datums, chamfer/pilot and protrusion.
Assembly function	Retaining member, engagement, stack, fixed/moving regions and separate axial/rotational requirements.
Receiving component	Hole drawing, material/hardness condition, wall section, blind/through depth and entry geometry.
Installation and acceptance	Direction/access, support, selected process, inspection and qualified acceptance criteria.
Material and purchase	Grade/finish, inspection documents, drawing or sample, quantity/packing/destination; feasibility and timing unconfirmed.

Common product questions

Is a helical knurled pin a screw?

No. The knurl is a retention feature, not an assumed screw-thread interface. Specify the selected pin and receiving-hole design; do not apply a generic tightening torque.

Can straight and helical knurls be interchanged?

Not by diameter alone. Pattern, contact envelope, engagement and installation behaviour differ. Review axial and rotational requirements for the selected assembly.

Must the knurl cover the entire length?

No. The original maker identifies modified length and position options. Any partial pattern needs a controlled drawing defining retained and smooth regions, and feasibility confirmation.

Does ISO 13444 certify the pin or joint?

No. It concerns knurl dimensioning and indication. Product dimensions, material, inspection and joint qualification remain separate requirements.

Product references

References checked 10 October 2026 identify structures, not FastenerBridge stock, certification or brand affiliation. Final requirements follow the selected specification. No universal dimensions, load rating or tightening torque is stated.