Skip to content
info@engineeringhardware.com
Request a Quote

General Components · GB/T 78 / ISO 4027

Grade 8.8 Steel Engineered Component — GB/T 78 / ISO 4027 (Series 026)

For Engineered Component — GB/T 78 / ISO 4027 (Series 026) in Grade 8.8 Steel, the controlling decisions are corrosion, strength and service temperature. This guide summarizes those three for Grade 8.8 Steel Engineered Component — GB/T 78 / ISO 4027 (Series 026) and lists every size we supply.

Why Choose Grade 8.8 Steel for Engineered Component — GB/T 78 / ISO 4027 (Series 026)

The workhorse medium-carbon alloy grade for structural joints. For engineered component — gb/t 78 / iso 4027 (series 026), this matters when requires plating (zinc) for corrosion protection is the primary requirement.

Mechanical & Physical Properties

Grade designationclass 8.8
Magnetic responseMagnetic
Service temperatureup to approx. +300 °C
Corrosion characteristicRequires plating (zinc) for corrosion protection

Corrosion Behavior in Service

Carbon and alloy steel engineered component — gb/t 78 / iso 4027 (series 026) 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.

Galvanic & Galling Considerations

For engineered component — gb/t 78 / iso 4027 (series 026) 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.

Sizes of Engineered Component — GB/T 78 / ISO 4027 (Series 026) Available in Grade 8.8 Steel

Size designationOuter diameter / width (mm)Length / height (mm)Bore / thread (mm)MaterialReference standard
Size 110206C45 carbon steelGB/T 1804-m
Size 212258C45 carbon steelGB/T 1804-m
Size 3163210C45 carbon steelGB/T 1804-m
Size 4204012C45 carbon steelGB/T 1804-m
Size 5255016C45 carbon steelGB/T 1804-m
Size 6326320C45 carbon steelGB/T 1804-m
Size 7408025C45 carbon steelGB/T 1804-m
Size 85010030C45 carbon steelGB/T 1804-m

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 78 / ISO 4027)

Size designationOuter diameter / width (mm)Length / height (mm)Bore / thread (mm)MaterialReference standard
Size 110206C45 carbon steelGB/T 1804-m
Size 212258C45 carbon steelGB/T 1804-m
Size 3163210C45 carbon steelGB/T 1804-m
Size 4204012C45 carbon steelGB/T 1804-m
Size 5255016C45 carbon steelGB/T 1804-m
Size 6326320C45 carbon steelGB/T 1804-m
Size 7408025C45 carbon steelGB/T 1804-m
Size 85010030C45 carbon steelGB/T 1804-m

Frequently Asked Questions

When should I move from class 8.8 to class 10.9 / 12.9 for Engineered Component — GB/T 78 / ISO 4027 (Series 026)?

Step up to class 10.9 / 12.9 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 8.8 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 Engineered Component — GB/T 78 / ISO 4027 (Series 026)?

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 8.8 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.