Mechanical properties, corrosion behaviour and the full dimensional range for this grade.
A2 Stainless Steel Extension Spring are supplied to ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70. Corrosion behaviour is good general corrosion resistance, 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 the most common stainless group for indoor and general outdoor fasteners.
Grade
ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70
Corrosion resistance
Good general corrosion resistance
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.
Hidden Deck Fasteners Sourcing: Manufacturing, Types & Material Compatibility
A2 Stainless Steel is not a material extension spring are supplied in. Extension Spring are specified by wire diameter, and this combination does not describe a part that exists.
A2 Stainless Steel is one of the grades the catalog describes. Dimensions, material, finish and form are specified from the drawing — a spring outside the standard range is a variation on existing tooling rather than a new design.
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 0.8 Extension Spring — ISO / DIN (Series 143). Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
Outer diameter De (mm)
6
Free length Lo (mm)
30
Initial tension F0 (N)
2
Rate k (N/mm)
2.5
Material
Music wire
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 / DIN)
Wire dia d (mm)
Outer diameter De (mm)
Free length Lo (mm)
Initial tension F0 (N)
Rate k (N/mm)
Material
Reference standard
0.8
6
30
2
2.5
Music wire
DIN 2097 / GB/T 23935
1.0
8
40
4
4.0
Music wire
DIN 2097 / GB/T 23935
1.2
10
50
6
6.5
Music wire
DIN 2097 / GB/T 23935
1.6
14
70
10
12.0
Music wire
DIN 2097 / GB/T 23935
2.0
18
90
18
20.0
Music wire
DIN 2097 / GB/T 23935
2.5
22
120
28
32.0
Music wire
DIN 2097 / GB/T 23935
3.0
28
150
45
55.0
Music wire
DIN 2097 / GB/T 23935
4.0
40
200
90
110.0
Music wire
DIN 2097 / GB/T 23935
Materials & Grades
Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents.
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
Should I choose A2 Stainless Steel or A4 (316) for Extension Spring — ISO / DIN (Series 143)?
For Extension Spring — ISO / DIN (Series 143), A2 Stainless Steel suits general indoor and outdoor use; A4 (316) is preferred for marine, coastal and chemical environments. Choose by corrosion exposure first.
Can A2 Stainless Steel Extension Spring — ISO / DIN (Series 143) 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 A2 Stainless Steel food-grade?
A2 (304) is widely accepted for food contact in non-chloride environments; A4 (316) is preferred where chlorides are present.
Can A2 Stainless Steel Extension Spring — ISO / DIN (Series 143) 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.
Need a fastener quote or a spec sheet?Message our engineers on WhatsApp — send a drawing or DIN number and get pricing back fast.Start WhatsApp Chat →
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