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Screws · GB/T 818 / ISO 7045

Grade 12.9 Steel Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034)

When Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034) are required in Grade 12.9 Steel, the alternative grades and the trade-offs between them matter as much as the dimensions. This page covers both, plus mechanical and corrosion data.

Why Choose Grade 12.9 Steel for Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034)

The highest common strength class, for high-load machine assembly. For phillips pan head machine screw — gb/t 818 / iso 7045 (series 034), 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 phillips pan head machine screw — gb/t 818 / iso 7045 (series 034) 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 Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034), 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 Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034) Available in Grade 12.9 Steel

SizePitch (mm)Length L (mm)Head diameter dk (mm)Head height k (mm)Cross recessReference standard
M30.5205.61.8PH1ISO 7045 / GB/T 818
M40.7258.02.4PH2ISO 7045 / GB/T 818
M50.8309.53.0PH2ISO 7045 / GB/T 818
M61.04012.03.6PH3ISO 7045 / GB/T 818
M81.255016.04.8PH3ISO 7045 / GB/T 818
M101.56020.06.0PH4ISO 7045 / GB/T 818

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 (GB/T 818 / ISO 7045)

SizePitch (mm)Length L (mm)Head diameter dk (mm)Head height k (mm)Cross recessReference standard
M30.5205.61.8PH1ISO 7045 / GB/T 818
M40.7258.02.4PH2ISO 7045 / GB/T 818
M50.8309.53.0PH2ISO 7045 / GB/T 818
M61.04012.03.6PH3ISO 7045 / GB/T 818
M81.255016.04.8PH3ISO 7045 / GB/T 818
M101.56020.06.0PH4ISO 7045 / GB/T 818

Frequently Asked Questions

What corrosion resistance do Grade 12.9 Steel Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034) offer?

Grade 12.9 Steel Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034) provide requires plating or black-oxide protection with a service range of up to approx. +300 °C.

When should I move from class 12.9 to class 8.8 for Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034)?

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 Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034)?

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.

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.