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Pins · ISO 8734 / DIN 6325

Grade 12.9 Steel Dowel Pins

Specifying Dowel Pins in Grade 12.9 Steel pairs the dimensional form of Dowel Pins (ISO 8734 / DIN 6325) with the engineering properties of Grade 12.9 Steel. This page explains when to choose the grade, how it behaves in service, and which grades to compare it against.

Why Choose Grade 12.9 Steel for Dowel Pins

The highest common strength class, for high-load machine assembly. For dowel pins, this matters when requires plating or black-oxide protection is the primary requirement.

Mechanical & Physical Properties

Grade designationclass 12.9
Magnetic responseMagnetic
Service temperatureup to approx. +300 °C
Corrosion characteristicRequires plating or black-oxide protection

Galvanic & Galling Considerations

For dowel pins in steel, the dominant compatibility issue is hydrogen embrittlement at high property classes (10.9 and above) when electroplated. Plating must be followed by an appropriate baking treatment, or a non-electroplated finish (mechanical zinc, zinc flake) should be substituted.

Comparable Grades

For Dowel Pins, class 8.8 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.

Sizes of Dowel Pins Available in Grade 12.9 Steel

Nominal diameter (mm)Diameter toleranceCommon length range (mm)MaterialHardnessReference standardNotes
1.0h64~10Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
1.2h64~12Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
1.5h64~16Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
2.0h66~20Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
2.5h66~24Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
3.0h68~30Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
4.0h68~40Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
5.0h610~50Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
6.0h612~60Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
8.0h616~80Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
10.0h620~100Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
12.0h625~120Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
16.0h630~160Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
20.0h635~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
25.0h645~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
30.0h650~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
40.0h660~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
50.0h680~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit

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.

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Adjust the parameters in the drawing above and click "Request this configuration" to send the exact specification straight to this form.

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Specification
Business Information

Dimensions & Specifications (ISO 8734 / DIN 6325)

Nominal diameter (mm)Diameter toleranceCommon length range (mm)MaterialHardnessReference standardNotes
1.0h64~10Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
1.2h64~12Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
1.5h64~16Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
2.0h66~20Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
2.5h66~24Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
3.0h68~30Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
4.0h68~40Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
5.0h610~50Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
6.0h612~60Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
8.0h616~80Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
10.0h620~100Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
12.0h625~120Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
16.0h630~160Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
20.0h635~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
25.0h645~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
30.0h650~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
40.0h660~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit
50.0h680~200Alloy steelHardenedISO 8734 / DIN 6325Both ends chamfered, precision fit

Frequently Asked Questions

When should I move from class 12.9 to class 8.8 for Dowel Pins?

Step up to class 8.8 when the joint preload approaches the proof load of the current class. The higher class adds preload at the same diameter, often saving size and weight.

Is Grade 12.9 Steel prone to hydrogen embrittlement?

Class 10.9 and above can be susceptible to hydrogen embrittlement when electroplated. Specify post-plating baking, or use mechanical-zinc / zinc-flake finishes which avoid the cathodic plating step.

Which finish is best for outdoor Dowel Pins?

For outdoor service in steel, hot-dip galvanizing gives the longest life; zinc-flake (Geomet/Delta-Tone family) gives a thinner film with excellent salt-spray performance; standard zinc plating is the lowest-cost option for general indoor / shielded outdoor use.

What's the service temperature limit for Grade 12.9 Steel?

The practical service range is up to approx. +300 °C.

How do I request a quotation?

Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.