Skip to content

Screws · GB/T 1228 / ASTM A325

A4 Stainless Steel Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046)

For Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) in A4 Stainless Steel, the controlling decisions are corrosion, strength and service temperature. This guide summarizes those three for A4 Stainless Steel Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) and lists every size we supply.

Why Choose A4 Stainless Steel for Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046)

Specified for marine, coastal and chemical applications. For heavy hex socket head cap screw — gb/t 1228 / astm a325 (series 046), this matters when superior, including marine and chloride environments is the primary requirement.

Mechanical & Physical Properties

Grade designationA4-80 (316)
Magnetic responseLargely non-magnetic
Service temperatureapprox. -200 °C to +400 °C
Corrosion characteristicSuperior, including marine and chloride environments

Corrosion Behavior in Service

A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.

Comparable Grades

For Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046), the alternative stainless grade is A2 (304). A2 (304) suits general indoor and outdoor service; A4 (316) adds molybdenum for marine and chloride environments. Where higher strength matters more than corrosion, switch to plated alloy-steel class 8.8 or 10.9.

Sizes of Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) Available in A4 Stainless Steel

SizePitch (mm)Length L (mm)Head diameter dk (mm)Head height k (mm)Hex socket s (mm)Reference standard
M30.5205.532.5ISO 4762 / GB/T 70.1
M40.7257.043.0ISO 4762 / GB/T 70.1
M50.8308.554.0ISO 4762 / GB/T 70.1
M61.04010.065.0ISO 4762 / GB/T 70.1
M81.255013.086.0ISO 4762 / GB/T 70.1
M101.56016.0108.0ISO 4762 / GB/T 70.1
M121.758018.01210.0ISO 4762 / GB/T 70.1
M142.08021.01412.0ISO 4762 / GB/T 70.1
M162.010024.01614.0ISO 4762 / GB/T 70.1
M182.510027.01814.0ISO 4762 / GB/T 70.1
M202.512030.02017.0ISO 4762 / GB/T 70.1
M243.015036.02419.0ISO 4762 / GB/T 70.1
M303.518045.03022.0ISO 4762 / GB/T 70.1
M364.020054.03627.0ISO 4762 / GB/T 70.1

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 (GB/T 1228 / ASTM A325)

SizePitch (mm)Length L (mm)Head diameter dk (mm)Head height k (mm)Hex socket s (mm)Reference standard
M30.5205.532.5ISO 4762 / GB/T 70.1
M40.7257.043.0ISO 4762 / GB/T 70.1
M50.8308.554.0ISO 4762 / GB/T 70.1
M61.04010.065.0ISO 4762 / GB/T 70.1
M81.255013.086.0ISO 4762 / GB/T 70.1
M101.56016.0108.0ISO 4762 / GB/T 70.1
M121.758018.01210.0ISO 4762 / GB/T 70.1
M142.08021.01412.0ISO 4762 / GB/T 70.1
M162.010024.01614.0ISO 4762 / GB/T 70.1
M182.510027.01814.0ISO 4762 / GB/T 70.1
M202.512030.02017.0ISO 4762 / GB/T 70.1
M243.015036.02419.0ISO 4762 / GB/T 70.1
M303.518045.03022.0ISO 4762 / GB/T 70.1
M364.020054.03627.0ISO 4762 / GB/T 70.1

Frequently Asked Questions

Should I choose A4 Stainless Steel or A2 (304) for Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046)?

For Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046), A4 Stainless Steel suits general indoor and outdoor use; A2 (304) is preferred for marine, coastal and chemical environments. Choose by corrosion exposure first.

Can A4 Stainless Steel Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) gall during installation?

Yes — stainless on stainless is prone to thread galling under load, especially at smaller sizes. Use an anti-galling lubricant or wax thread compound, and slow the tightening rate where possible.

Is A4 Stainless Steel food-grade?

A4 (316) is the standard food-contact stainless grade in most jurisdictions, particularly where chloride exposure (brines, dairy CIP) is present.

Can A4 Stainless Steel Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) be used with aluminum?

Yes, but stainless drives mild galvanic corrosion of aluminum in wet service — isolate with a coating, sleeve or paint, or accept the trade-off if the joint is dry and indoor.

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.