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Pins · ISO 8736 · Application guide

What Are Taper Pins with Internal Thread, Unhardened Used For?

Typical applications, the industries that specify taper pins with internal thread, unhardened, and how to choose the right size, material and finish for the joint.

Taper Pins with Internal Threads, Unhardened are used for an unhardened taper pin with an internal thread so it can be pulled from a blind hole. They are manufactured to ISO 8736, and selection is driven by the nominal diameter, the fit and tolerance the assembly requires, and the service environment.

Primary duty
An unhardened taper pin with an internal thread so it can be pulled from a blind hole
Governing standard
ISO 8736
Nominal diameter range
6 mm to 50 mm
Category
Pins

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

What Are Taper Pins with Internal Thread, Unhardened Used For? application image

Taper Pins with Internal Threads, Unhardened are selected when an assembly calls for an unhardened taper pin with an internal thread so it can be pulled from a blind hole. This application guide to the ISO 8736 type covers concrete end-uses, the specification checklist, correct installation, and where an alternative fastener performs better. Stocked across roughly 6 mm to 50 mm, they cover general to heavy-duty work.

Typical Applications for Taper Pins with Internal Thread, Unhardened

The most common settings where these are specified:

  • Machine building: location in blind holes.
  • Gearboxes: housing halves aligned before bolting.
  • Tooling: repeatably aligned fixtures.
  • Maintenance: pins that must come out.

How to Specify Taper Pins with Internal Thread, Unhardened 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 6 mm–50 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 8736. 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 Taper Pins with Internal Thread, Unhardened

  • 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 Taper Pins with Internal Thread, Unhardened 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 taper pins with internal thread, unhardened outside the standard range?

Diameter, length, tolerance class, hardness and end form are specifiable. Ground diameters are held after heat treatment rather than before. 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 6 mm Taper Pins with Internal Thread, Unhardened to ISO 8736. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
d_1 (mm)
6
a (mm)
0.8
d_2 (mm)
4
Pitch P (mm)
0.7
d_3 (mm)
4.3
t_1 (mm)
6
t_2 (mm)
10
t_3 (mm)
1
Length range l (mm)
16~60
Sends the selected values to the quote form below.

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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 8736)

Nominal diameter d (mm)d_1 (mm)a (mm)d_2 (mm)Pitch P (mm)d_3 (mm)t_1 (mm)t_2 (mm)t_3 (mm)Length range l (mm)Reference standard
6 mm60.840.74.3610116~60ISO 8736
8 mm8150.85.38121.218~80ISO 8736
10 mm101.2616.410161.222~100ISO 8736
12 mm121.681.258.412201.226~120ISO 8736
16 mm162101.510.516251.532~160ISO 8736
20 mm202.5121.751318281.540~200ISO 8736
25 mm253162172435250~200ISO 8736
30 mm304202.5213040260~200ISO 8736
40 mm405202.52130402.580~200ISO 8736
50 mm506.32432536502.5100~200ISO 8736
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 material should Taper Pins with Internal Thread, Unhardened 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 Taper Pins with Internal Thread, Unhardened made to a recognized standard?

Yes — they are manufactured to ISO 8736, so dimensions are interchangeable between suppliers when you quote the standard on your order.

What are Taper Pins with Internal Thread, Unhardened used for?

An unhardened taper pin with an internal thread so it can be pulled from a blind hole. They are supplied to ISO 8736.

Which industries use Taper Pins with Internal Thread, Unhardened?

They are commonly specified in machine building, gearboxes and tooling, among other sectors.

Can I get a quote for Taper Pins with Internal Thread, Unhardened 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.