FARBO 250 - Tempered chrome silicon steel wire with high tensile strength properties

Oil tempered spring wire - Suspension springs quality

trade, sales, commerce, marketing, distribution, oil tempered steel wire, tempered chrome silicon steel wire with high tensile strength properties, suspension springs quality, EN 10270-2 FD CrSi, EN 10270-2 FDCrSi, DIN 17223/2 FD, DIN 50602, M method, coil end tested

In compliance with:
F.A.R. internal standard
For the properties not provided here, quality FD CrSi, EN 10270-2 shall be considered
DIN 17223/2 FD

Utilization:
Highly dynamic stress springs, i.e. suspension springs or similar which work at highly dynamic regime and require good relaxation properties and heat resistance at high working temperature

Diameters:
2.50 - 13.50 mm

Chemical composition:

C	Si	Mn	P	S	Cu	Cr
0.50 - 0.60	1.20 - 1.60	0.50 - 0.90	<0.03	<0.02	<0.12	0.50 - 0.80

Raw Material:
Wire rod from qualified international steelworks

Non metallic inclusions:
In compliance with DIN 50602, M method, for all kind of inclusions the maximum size is No. 2

Mechanical and technological properties:

Nominal diameter (a < Ø ≤ b) [mm]	Allowed deviations (±) [mm]	Tensile strength [N/mm²]	Minimum reduction [Z %]	Minimum number of twists Lo = 50 × d Min. 100% Right - Left
2.50 - 3.00	0.025	2000 - 2120	45	to be agreed upon
3.00 - 3.20	0.025	1970 - 2090	45	to be agreed upon
3.20 - 3.40	0.025	1960 - 2080	45	to be agreed upon
3.40 - 3.60	0.025	1940 - 2060	45	to be agreed upon
3.60 - 3.80	0.025	1930 - 2050	45	to be agreed upon
3.80 - 4.00	0.025	1920 - 2040	45	to be agreed upon
4.00 - 4.25	0.025	1920 - 2040	45	to be agreed upon
4.25 - 4.50	0.025	1900 - 2020	45	to be agreed upon
4.50 - 4.75	0.025	1890 - 2010	45	to be agreed upon
4.75 - 5.00	0.025	1880 - 2000	45	to be agreed upon
5.00 - 5.30	0.030	1880 - 2000	45	to be agreed upon
5.30 - 5.60	0.030	1860 - 1980	40	to be agreed upon
5.60 - 6.00	0.030	1850 - 1970	40	to be agreed upon
6.00 - 6.30	0.030	1840 - 1960	40	to be agreed upon
6.30 - 6.50	0.030	1830 - 1950	40	to be agreed upon
6.50 - 7.00	0.030	1830 - 1950	40	to be agreed upon
7.00 - 7.50	0.030	1810 - 1930	40	to be agreed upon
7.50 - 8.00	0.030	1800 - 1920	40	to be agreed upon
8.00 - 8.50	0.030	1790 - 1910	40	not expected
8.50 - 9.00	0.030	1780 - 1900	35	not expected
9.00 - 9.50	0.030	1770 - 1890	35	not expected
9.50 - 10.00	0.030	1760 - 1880	35	not expected
10.00 - 10.50	0.030	1750 - 1870	35	not expected
10.50 - 11.00	0.040	1740 - 1860	35	not expected
11.00 - 12.00	0.040	1730 - 1850	35	not expected
12.00 - 12.50	0.040	1720 - 1840	35	not expected
12.50 - 13.50	0.040	1700 - 1830	35	not expected

• Allowed depth of surface defects at the coil ends: max. 1.3% of wire diameter
• Allowed depth of surface decarburisation at the coil ends: max. 1.3% of wire diameter
• Maximum permissible tensile strength variation within one coil: 50 N/mm²
• Out of roundness: i.e. the difference between the maximum and minimum diameter of the wire at the same cross section is not more than 50% of the total permissible deviation in the diameter
• Yield point (limit 0.2%): minimum 90% of tensile strength
• Elastic modulus: E = 206 kN/mm² (nominal value)
• Shear modulus: G = 79.5 kN/mm² (nominal value)
• Heat treatment: after the coiling the springs should be stress relieved at T = 420 ± 5°C for 30 min; after shoot peening should be stress relieved at T = 250 ± 10°C for 30 min