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Washers · GB/T 858

Grade 12.9 Steel Tab Lock Washer for Round Nut

Grade 12.9 Steel Tab Lock Washer for Round Nut reference image

Tab Lock Washer for Round Nut manufactured in Grade 12.9 Steel (class 12.9) are dimensioned to GB/T 858. The sections below give the mechanical and physical properties of the grade, its behavior in corrosive and elevated-temperature service, and the full size table.

Why Choose Grade 12.9 Steel for Tab Lock Washer for Round Nut — GB/T 858 (Series 072)

The highest common strength class, for high-load machine assembly. For tab lock washer for round nut — gb/t 858 (series 072), 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

Corrosion Behavior in Service

Carbon and alloy steel tab lock washer for round nut — gb/t 858 (series 072) 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.

Comparable Grades

For Tab Lock Washer for Round Nut — GB/T 858 (Series 072), 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 Tab Lock Washer for Round Nut — GB/T 858 (Series 072) Available in Grade 12.9 Steel

For shaft / nut sizeInner diameter d1 (mm)Outer diameter d2 (mm)Thickness t (mm)Tab length (mm)Reference standard
M1010.5211.08GB/T 858
M1212.5251.09GB/T 858
M1616.5301.010GB/T 858
M2020.5381.512GB/T 858
M2424.5451.514GB/T 858
M3030.5551.516GB/T 858
M3636.5652.018GB/T 858
M4848.5852.020GB/T 858
M6060.51052.524GB/T 858

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 858)

For shaft / nut sizeInner diameter d1 (mm)Outer diameter d2 (mm)Thickness t (mm)Tab length (mm)Reference standard
M1010.5211.08GB/T 858
M1212.5251.09GB/T 858
M1616.5301.010GB/T 858
M2020.5381.512GB/T 858
M2424.5451.514GB/T 858
M3030.5551.516GB/T 858
M3636.5652.018GB/T 858
M4848.5852.020GB/T 858
M6060.51052.524GB/T 858

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 Tab Lock Washer for Round Nut — GB/T 858 (Series 072)?

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.