Tools · ISO 6789 (hand torque tools — requirements and test methods)
A4 (316) Stainless Steel Torque Wrenches for Fastener Tightening
Mechanical properties, corrosion behaviour and the full dimensional range for this grade.
A4 Stainless Steel Torque Wrenches for Fastener Tightening are supplied to ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80. Corrosion behaviour is superior, including marine and chloride environments, the material is largely non-magnetic, and the usable service range is approx. -200 °C to +400 °C, subject to the property class and the joint. In practice this grade is specified for marine, coastal and chemical applications.
Grade
ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80
Corrosion resistance
Superior, including marine and chloride environments
Magnetic response
Largely non-magnetic
Service temperature
approx. -200 °C to +400 °C, subject to the property class and the joint
Property values are typical for the grade. Certified mechanical test data is available on request for production orders.
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A4 Stainless Steel is not a material torque wrenches for fastener tightening are supplied in. Torque Wrenches for Fastener Tightening are specified by nominal size, and this combination does not describe a part that exists.
Need this fastener tool in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. A non-standard fastener tool is quoted from the drawing; where one already exists in the catalog, the special is usually a variation on its tooling.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
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.
Dimensioned line drawing of 1 – 6 N·m Torque Wrenches for Fastener Tightening to ISO 6789 (hand torque tools — requirements and test methods). Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
Square drive
1/4 in
Typical bolt size at mid-range
M3 – M4
Class
ISO 6789 click type
Sends the selected values to the quote form below.
Request a Quote
The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.
Dimensions & Specifications (ISO 6789 (hand torque tools — requirements and test methods))
Assembly & maintenanceInstalling and servicing the fasteners in this catalog.
Typical applications
calibrating to a schedule and after any drop
tightening in a smooth pull, not in jerks
selecting a wrench whose mid-range covers the working torque
winding a click wrench back to its lowest setting for storage
driving and releasing fasteners on the bench and in the field
Where to use something else
Do not use a torque wrench to loosen a seized fastener; a single over-range pull puts the calibration out and every joint tightened afterwards is wrong.
This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.
01
Cold heading
Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.
Head dimensions and under-head radius checked at set-up and per shift.
02
Thread rolling
Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.
Go / no-go ring gauges to ISO 965 tolerance class 6g.
03
Heat treatment
Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.
Core hardness and tensile tested per lot to ISO 898-1.
04
Surface treatment
Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.
Coating thickness and neutral salt spray hours to ISO 9227.
Frequently Asked Questions
Can A4 Stainless Steel Torque Wrenches for Fastener Tightening 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 Torque Wrenches for Fastener Tightening 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.
What's the service temperature limit for A4 Stainless Steel?
The practical service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
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.
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