Skip to content
info@engineeringhardware.com
Request a Quote

Pipe & Pneumatic Fittings · ISO 228 (G)

Grade 12.9 Steel BSP Pipe Thread Fittings

Grade 12.9 Steel BSP Pipe Thread Fittings pairs the standard ISO 228 (G) with a Grade 12.9 Steel base material. The sections below cover why engineers select this grade for bsp pipe thread fittings, its corrosion and temperature behavior, and the sizes available.

Why Choose Grade 12.9 Steel for BSP Pipe Thread Fittings

The highest common strength class, for high-load machine assembly. For bsp pipe thread fittings, 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 bsp pipe thread fittings 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 BSP Pipe Thread Fittings, 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 BSP Pipe Thread Fittings Available in Grade 12.9 Steel

SizeNominal size (in)Major diameter (mm)Pitch (mm)Threads per inch (TPI)Tap drill (mm)Reference standardNotes
G1/161/167.7230.907286.8ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1/81/89.7280.907288.8ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1/41/413.1571.3371911.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G3/83/816.6621.3371915.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1/21/220.9551.8141418.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G5/85/822.9111.8141420.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G3/43/426.4411.8141424.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G7/87/830.2011.8141427.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1133.2492.3091130.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1-1/81-1/837.8972.3091135.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1-1/41-1/441.912.3091139.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1-1/21-1/247.8032.3091145.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1-3/41-3/453.7462.3091151.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G2259.6142.3091157.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G2-1/42-1/465.712.3091163.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G2-1/22-1/275.1842.3091172.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G2-3/42-3/481.5342.3091179.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G3387.8842.3091185.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G3-1/23-1/2100.332.3091197.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G44113.032.30911110.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G55138.432.30911135.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G66163.832.30911160.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket

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.

Request a Quotation

Specification
Business Information

Dimensions & Specifications (ISO 228 (G))

SizeNominal size (in)Major diameter (mm)Pitch (mm)Threads per inch (TPI)Tap drill (mm)Reference standardNotes
G1/161/167.7230.907286.8ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1/81/89.7280.907288.8ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1/41/413.1571.3371911.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G3/83/816.6621.3371915.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1/21/220.9551.8141418.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G5/85/822.9111.8141420.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G3/43/426.4411.8141424.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G7/87/830.2011.8141427.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1133.2492.3091130.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1-1/81-1/837.8972.3091135.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1-1/41-1/441.912.3091139.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1-1/21-1/247.8032.3091145.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G1-3/41-3/453.7462.3091151.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G2259.6142.3091157.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G2-1/42-1/465.712.3091163.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G2-1/22-1/275.1842.3091172.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G2-3/42-3/481.5342.3091179.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G3387.8842.3091185.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G3-1/23-1/2100.332.3091197.5ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G44113.032.30911110.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G55138.432.30911135.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket
G66163.832.30911160.0ISO 228-1 / DIN ISO 228Parallel pipe thread (G), sealed by gasket

Frequently Asked Questions

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 BSP Pipe Thread Fittings?

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.

Can Grade 12.9 Steel replace stainless steel structurally?

No — stainless A2/A4 cannot match class 10.9 / 12.9 strength. Stainless is selected for corrosion, not raw strength.

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.