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Pins · Trade series (GN 615) · Application guide

What Are Threaded Spring Plungers Used For?

Typical applications, the industries that specify threaded spring plungers, and how to choose the right size, material and finish for the joint.

Threaded Spring Plungers are used for threaded spring-loaded detent and locating contact. They are manufactured to Trade series (GN 615), and selection is driven by the thread size, the fit and tolerance the assembly requires, and the service environment.

Primary duty
Threaded spring-loaded detent and locating contact
Governing standard
Trade series (GN 615)
Thread size range
M2 to M20
Category
Pins

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

What Are Threaded Spring Plungers Used For? application image

Threaded Spring Plungers are used primarily for threaded spring-loaded detent and locating contact. This page lists the industries and assemblies where they are specified, the selection criteria that matter for each application, installation practice, and the cases where a different fastener type is the correct choice. Parts are supplied to Trade series (GN 615). Stocked across roughly M2 to M20, they cover general to heavy-duty work.

Typical Applications for Threaded Spring Plungers

The most common settings where these are specified:

  • Jig and fixture building: threaded spring plungers used for stops and repeat location.
  • Machine guarding: spring contacts that hold removable covers in position.
  • Conveyor changeover: low-force positioning of guides and adjustable stops.
  • Instrument controls: small locating contacts under knobs and slides.

How to Specify Threaded Spring Plungers for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans M2–M20; 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 Trade series (GN 615). 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 Threaded Spring Plungers

  • 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 Threaded Spring Plungers Are Not the Right Choice

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

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.

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 (Trade series (GN 615))

Thread sizePlunger typesHousing materialBall materialSpring material
M2K / KS / KN / KSNblackened steel or AISI 303 stainlesshardened steel or AISI 420C stainlessAISI 631
M3K / KS / KN / KSNblackened steel or AISI 303 stainlesshardened steel or AISI 420C stainlessAISI 631
M4K / KS / KN / KSNblackened steel or AISI 303 stainlesshardened steel or AISI 420C stainlessAISI 631
M5K / KS / KN / KSNblackened steel or AISI 303 stainlesshardened steel or AISI 420C stainlessAISI 631
M6K / KS / KN / KSNblackened steel or AISI 303 stainlesshardened steel or AISI 420C stainlessAISI 631
M8K / KS / KN / KSNblackened steel or AISI 303 stainlesshardened steel or AISI 420C stainlessAISI 631
M12K / KS / KN / KSNblackened steel or AISI 303 stainlesshardened steel or AISI 420C stainlessAISI 631
M20K / KS / KN / KSNblackened steel or AISI 303 stainlesshardened steel or AISI 420C stainlessAISI 631
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

What are Threaded Spring Plungers used for?

Threaded spring-loaded detent and locating contact. They are supplied to Trade series (GN 615).

Which industries use Threaded Spring Plungers?

They are commonly specified in machine guarding, conveyor changeover and instrument controls, among other sectors.

How do I choose the right size of Threaded Spring Plungers?

Match the nominal size to the mating thread or hole. This product is available from M2 to M20; the full dimension table on this page lists each size.

What material should Threaded Spring Plungers 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.

Can I get a quote for Threaded Spring Plungers 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.