Grade 12.9 Steel Phillips Pan Head Machine Screw

Grade 12.9 Steel (class 12.9) is the highest common strength class, for high-load machine assembly. When phillips pan head machine screw are specified in this grade, the dimensions remain per GB/T 818 / ISO 7045; the material determines corrosion behavior (requires plating or black-oxide protection) and the service temperature range (up to approx. +300 °C). Both are covered below with the size table.

Why Choose Grade 12.9 Steel for Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 033)

The highest common strength class, for high-load machine assembly. For phillips pan head machine screw — gb/t 818 / iso 7045 (series 033), this matters when requires plating or black-oxide protection is the primary requirement.

Mechanical & Physical Properties

Galvanic & Galling Considerations

For phillips pan head machine screw — gb/t 818 / iso 7045 (series 033) 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 033), 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 033) Available in Grade 12.9 Steel