Material
Patented drawn spring steel wire in compliance with EN 10270 part 1 type DH for all wire diameters up to 1.9 mm. For diameters between 2.0 and 10.0 mm type SH will be used (AMS 5112 / BS 5216-75). Our stainless steel springs are manufactured using spring steel wire material no.1.4310 in compliance with EN 10270 part 3 (AISI 302 / BS 301S21). The tolerances of the wire diameters comply with DIN 2076.
Design
The springs are right-hand coiled (clockwise).
right-hand coiled
The length of each spring is 1000mm. The spring bodies do not have any loops.
Thermal treatment
The endless extension springs are not thermally treated, in order to allow the loops to be bent accurately. The springs should be tempered before being employed as extension springs. Thermal coating / 30 minutes at 240° C / air-cooled. We will undertake a thermal coating with pleasure whenever requested.
Loads
The indicated maximum load (Fn) is the maximum load which that particular spring can withstand. The stated spring rate (R1) applies to the compression of one coil. If a spring has several coils the spring rate can be calculated by dividing (R1) by the number of active coils (n) [R=R1/n]. The maximum extended length is determined by multiplying the number of active coils with the maximum extension of one coil [sn=sn1· n]. For endless extension springs, the preload force tolerance (F0tol) is +/- 100% due to the manufacturing length.
Surface treatment
Endless extension springs made of spring-steel wire EN 10270-1-DH and -SH will be ligthly oiled after the thermal coating. Springs made of material EN 10270-3-1.4310 will not be re-coated after production, as a surface protection is not normally required. All subsequent surface treatments cause unavoidable delay, as the application of a protective layer between the coils is very difficult due to the preset nature of the spring body. Here the selection of a suitable material should be made for an additional surface coating.
Quality control
Extension springs are tested for compliance to the tolerated loads and measurements before they are approved and reach the production warehouse. The tests take place in our quality control department according to DIN ISO 2859-1 level II. The procedure normally consists of a simple spot check programme, test-level AQL=1.0. Specific tests can also be carried out and documented for each individual spring upon the customer's request. The following charges apply for the quality control certificates issued by us.
In compilance with:
DIN EN 10204-2.1 (DIN 50049-2.1)
DIN EN 10204-2.2 (DIN 50049-2.2)
DIN EN 10204-2.3 (DIN 50049-2.3)
DIN EN 10204-3.1B (DIN 50049-3.1B)
Testing of prototypes
Production compensation
In order to maintain the stated tolerated measurements we need to carry out production compensation with either the pre-stress (F0) or the wire diameter (d).
Calculation
The calculation and design of the endless extension springs is carried out in accordance with DIN specification 13906, section 2. DIN 2097 Grade II is taken as the basic standard for the tolerances.
spring materials
Here you can see a selection of our normal spring materials, they we have on stock. In all questions to the right selection of spring material, please contact our Department Engineering:
Gutekunst Federn · Dep. Engineering · Gewerbegebiet · D-02733 Cunewalde
Tel. (+49) 035877/227-11 · Fax (+49) 035877/227-14 · technik@gutekunst-co.com
surface treatments
Here you can see a selection of our normal surface treatments, they we can produce for you in addition. In all questions to the right surface treatment, please contact our Department Engineering:
Gutekunst Federn · Dep. Engineering · Carl-Zeiss-Strasse 15 · D-72555 Metzingen
Tel. +49 (0)7123 960-193 · Fax +49 (0)7123 960-150 · technik@gutekunst-co.com