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Screws · ISO 4762 / DIN 912

Grade 12.9 Steel Socket Head Cap Screws

Specifying Socket Head Cap Screws in Grade 12.9 Steel pairs the dimensional form of Socket Head Cap Screws (ISO 4762 / DIN 912) 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 Socket Head Cap Screws

The highest common strength class, for high-load machine assembly. For socket head cap screws, 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

Corrosion Behavior in Service

Carbon and alloy steel socket head cap screws require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.

Comparable Grades

For Socket Head Cap Screws, 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 Socket Head Cap Screws Available in Grade 12.9 Steel

SizePitch (mm)Head diameter dk (mm)Head height k (mm)Hex key s (mm)Socket depth t min (mm)Reference standard
M10.251.91.00.70.5ISO 4762 / DIN 912
M1.20.252.31.20.90.6ISO 4762 / DIN 912
M1.40.32.61.41.00.7ISO 4762 / DIN 912
M1.60.353.01.61.50.7ISO 4762 / DIN 912
M20.43.82.01.51.0ISO 4762 / DIN 912
M2.50.454.52.52.01.1ISO 4762 / DIN 912
M30.55.53.02.51.3ISO 4762 / DIN 912
M40.77.04.03.02.0ISO 4762 / DIN 912
M50.88.55.04.02.5ISO 4762 / DIN 912
M61.010.06.05.03.0ISO 4762 / DIN 912
M81.2513.08.06.04.0ISO 4762 / DIN 912
M101.516.010.08.05.0ISO 4762 / DIN 912
M121.7518.012.010.06.0ISO 4762 / DIN 912
M142.021.014.012.07.0ISO 4762 / DIN 912
M162.024.016.014.08.0ISO 4762 / DIN 912
M182.527.018.014.09.0ISO 4762 / DIN 912
M202.530.020.017.010.0ISO 4762 / DIN 912
M222.533.022.017.011.0ISO 4762 / DIN 912
M243.036.024.019.012.0ISO 4762 / DIN 912
M273.040.027.019.013.5ISO 4762 / DIN 912
M303.545.030.022.015.5ISO 4762 / DIN 912
M333.550.033.024.017.5ISO 4762 / DIN 912
M364.054.036.027.019.0ISO 4762 / DIN 912
M424.563.042.032.021.0ISO 4762 / DIN 912
M485.072.048.036.025.0ISO 4762 / DIN 912

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

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 4762 / DIN 912)

SizePitch (mm)Head diameter dk (mm)Head height k (mm)Hex key s (mm)Socket depth t min (mm)Reference standard
M10.251.91.00.70.5ISO 4762 / DIN 912
M1.20.252.31.20.90.6ISO 4762 / DIN 912
M1.40.32.61.41.00.7ISO 4762 / DIN 912
M1.60.353.01.61.50.7ISO 4762 / DIN 912
M20.43.82.01.51.0ISO 4762 / DIN 912
M2.50.454.52.52.01.1ISO 4762 / DIN 912
M30.55.53.02.51.3ISO 4762 / DIN 912
M40.77.04.03.02.0ISO 4762 / DIN 912
M50.88.55.04.02.5ISO 4762 / DIN 912
M61.010.06.05.03.0ISO 4762 / DIN 912
M81.2513.08.06.04.0ISO 4762 / DIN 912
M101.516.010.08.05.0ISO 4762 / DIN 912
M121.7518.012.010.06.0ISO 4762 / DIN 912
M142.021.014.012.07.0ISO 4762 / DIN 912
M162.024.016.014.08.0ISO 4762 / DIN 912
M182.527.018.014.09.0ISO 4762 / DIN 912
M202.530.020.017.010.0ISO 4762 / DIN 912
M222.533.022.017.011.0ISO 4762 / DIN 912
M243.036.024.019.012.0ISO 4762 / DIN 912
M273.040.027.019.013.5ISO 4762 / DIN 912
M303.545.030.022.015.5ISO 4762 / DIN 912
M333.550.033.024.017.5ISO 4762 / DIN 912
M364.054.036.027.019.0ISO 4762 / DIN 912
M424.563.042.032.021.0ISO 4762 / DIN 912
M485.072.048.036.025.0ISO 4762 / DIN 912

Frequently Asked Questions

When should I move from class 12.9 to class 8.8 for Socket Head Cap Screws?

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 Socket Head Cap Screws?

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.