8 catalogued sizes. Pick any row and the technical drawing redraws to it.
Extension Spring are catalogued in od 6-40 mm, with long 30-200 mm. 8 sizes are held in the table below, and the technical drawing redraws to whichever row you select.
OD
6-40 mm
Long
30-200 mm
Catalogued sizes
8
Dimensions are nominal values from the governing standard. Confirm the tolerance class for your application before ordering.
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 Quotation for Extension Spring
The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.
Dimensions & Specifications (ISO / DIN)
Every row below is a starting point for the customizer above — pick any size and the drawing will redraw to that row.
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
Extension Spring — ISO / DIN (Series 143) are springs manufactured to ISO / DIN. This page lists the full dimensional range with the key specifications engineers need to select and specify them.
What Are Extension Spring — ISO / DIN (Series 143)?
Extension Spring — ISO / DIN (Series 143) are springs defined by ISO / DIN. They are selected by wire diameter and the dimensional characteristics shown below, and are available in a range of materials and finishes to suit the application and environment.
CAD Source Reference
This page is generated from an original native CAD part model (SolidWorks .SLDPRT) of the extension spring — iso / din (series 143) family maintained by our engineering team. The technical drawing shown above is rebuilt parametrically from the dimensional table, so it always reflects the exact size and configuration you select. Native CAD files (STEP / SLDPRT) can be supplied with your quotation on request.
Materials & Finishes
Springs are supplied in spring steel, and in stainless (302/316) or phosphor bronze where corrosion or non-magnetic behavior is required. The controlling specification is the wire diameter, the spring rate and the free length; ISO 898-1 property classes do not apply.
Specification Guides
Each size, material and standard of Extension Spring — ISO / DIN (Series 143) has its own reference page with the figures for that one configuration.
Goes With
Hardware commonly specified alongside Extension Spring — ISO / DIN (Series 143).
Pricing
Extension Spring — ISO / DIN (Series 143) are supplied to order. Pricing starts from approximately US$0.15 per piece for standard sizes in spring steel; final pricing depends on size, material, finish and order quantity (MOQ applies). Submit your exact configuration with the quote form above.
Custom manufacturing · Made to drawing
Need a extension spring outside the standard range?
A non-standard spring 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.
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.
Video: Extension Spring
Third-party video, selected automatically for this topic. It is not produced by Engineering Hardware and is not a specification source — use the tables on this page for dimensional data.
Frequently Asked Questions
What is the controlling standard for Extension Spring — ISO / DIN (Series 143)?
Extension Spring — ISO / DIN (Series 143) are manufactured to ISO / DIN. The dimensional values on this page follow that standard.
What is the size range of Extension Spring — ISO / DIN (Series 143)?
The table on this page lists 8 sizes for Extension Spring — ISO / DIN (Series 143), ranging from 0.8 to 4.0. Sizes outside the table can be quoted on request.
In which materials are Extension Spring — ISO / DIN (Series 143) supplied?
Extension Spring — ISO / DIN (Series 143) are supplied in spring steel SH/DH and stainless, with finishes including zinc plating, hot-dip galvanizing and black oxide. Choose material and finish to suit the load and the service environment for Extension Spring — ISO / DIN (Series 143).
How do I request a quotation?
Use the parametric drawing on this page to set the exact configuration (size, material, finish) and click "Request this configuration" — a specialist from Engineering Hardware will 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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