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Pins · ISO 8751 · Application guide

What Are Coiled Spring Pins, Light Duty Used For?

Typical applications, the industries that specify coiled spring pins, light duty, and how to choose the right size, material and finish for the joint.

Coiled Spring Pins, Light Duty are used for a light-duty coiled spring pin for soft or thin host materials. They are manufactured to ISO 8751, and selection is driven by the nominal diameter, the fit and tolerance the assembly requires, and the service environment.

Primary duty
A light-duty coiled spring pin for soft or thin host materials
Governing standard
ISO 8751
Nominal diameter range
1.2 mm to 8 mm
Category
Pins

Application notes are general engineering guidance. Verify the property class and any approval requirement against your own design calculation.

What Are Coiled Spring Pins, Light Duty Used For? application image

Coiled Spring Pins, Light Duty (ISO 8751) are specified where the joint requires a light-duty coiled spring pin for soft or thin host materials. The sections below cover the typical end-uses by industry, the size and material decisions for each, assembly practice, and the applications this fastener type is not suited to. Stocked across roughly 1.2 mm to 8 mm, they cover general to heavy-duty work.

Typical Applications for Coiled Spring Pins, Light Duty

The most common settings where these are specified:

  • Plastics: pins in plastic parts.
  • Electronics: small mechanisms.
  • Consumer goods: hinges and levers.
  • Light machinery: low-load pins.

How to Specify Coiled Spring Pins, Light Duty for Your Application

  • Size: Select on nominal diameter, then on the hole tolerance and fit class — the fit, not the diameter alone, determines whether the part locates or slips. This product spans 1.2 mm–8 mm; check the full table below for the exact dimensions of each size.
  • Material: Choose the material and finish for the service environment — plated steel for general use, stainless for corrosion resistance.
  • Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
  • Standard: This product is supplied to ISO 8751. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.

Installation & Assembly Practice

  • Ream the hole to the specified fit class; a dowel pressed into a drilled-only hole will not locate accurately.
  • Press pins in with steady force rather than hammer blows where possible, and chamfer the hole entry.

Common Selection Mistakes with Coiled Spring Pins, Light Duty

  • Using a dowel pin as a load-carrying shear bolt — dowels locate, they are not sized for sustained shear.
  • Ignoring the fit class: a locational fit and an interference fit need different hole tolerances.

Where Coiled Spring Pins, Light Duty Are Not the Right Choice

Not for carrying significant tensile or repeated heavy shear loads — use a bolt or a keyed joint for that.

Custom manufacturing · Made to drawing

Need a coiled spring pins, light duty outside the standard range?

Tolerance class is what a special pin usually turns on — a locating pin and a retaining pin want very different fits in the same nominal size. Made by cold heading or turning.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

Custom pin manufacturingSend a drawing

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Dimensioned line drawing of 1.2 mm Coiled Spring Pins, Light Duty to ISO 8751. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
d_1 (mm)
1.685
d_2 (mm)
1.4
a (mm)
0.5
s (mm)
0.08
Length range l (mm)
4~24
Sends the selected values to the quote form below.

Request a Quote

The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.

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Specification
Business Information

Dimensions & Specifications (ISO 8751)

Nominal diameter d (mm)d_1 (mm)d_2 (mm)a (mm)s (mm)Length range l (mm)Reference standard
1.2 mm1.6851.40.50.084~24ISO 8751
2 mm2.2051.90.70.114~40ISO 8751
2.5 mm2.7352.40.70.145~45ISO 8751
3 mm3.252.90.90.175~50ISO 8751
3.5 mm3.773.410.195~50ISO 8751
4 mm4.3253.91.10.228~60ISO 8751
5 mm5.354.851.30.2810~60ISO 8751
6 mm6.45.851.50.3312~75ISO 8751
8 mm8.4757.820.4516~120ISO 8751
Inside the plant

Manufactured in our own plant

This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.

  1. Wire rod feeding into a cold heading machine
    01

    Cold heading

    Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.

    Head dimensions and under-head radius checked at set-up and per shift.

  2. Thread rolling machine producing bolt threads
    02

    Thread rolling

    Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.

    Go / no-go ring gauges to ISO 965 tolerance class 6g.

  3. Baskets of bolts staged for heat treatment
    03

    Heat treatment

    Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.

    Core hardness and tensile tested per lot to ISO 898-1.

  4. Zinc plated bolts in a treatment basket
    04

    Surface treatment

    Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.

    Coating thickness and neutral salt spray hours to ISO 9227.

Frequently Asked Questions

Which industries use Coiled Spring Pins, Light Duty?

They are commonly specified in plastics, electronics and consumer goods, among other sectors.

How do I choose the right size of Coiled Spring Pins, Light Duty?

Select on nominal diameter and on the fit the assembly requires. This product is available from 1.2 mm to 8 mm; the full dimension table on this page lists each size.

What material should Coiled Spring Pins, Light Duty be for outdoor use?

For damp, coastal or chemical environments specify A4 (316) stainless or a suitably coated steel. For indoor or dry use, A2 (304) stainless or zinc-plated steel is normally adequate.

Are Coiled Spring Pins, Light Duty made to a recognized standard?

Yes — they are manufactured to ISO 8751, so dimensions are interchangeable between suppliers when you quote the standard on your order.

Can I get a quote for Coiled Spring Pins, Light Duty in the size and material I need?

Yes. Use the technical drawing and quote form on this page to set the size and options, then send the exact configuration to our team for pricing and lead time.