Steel Wires for Mechanical Spring – Oil Hardened & Tempered & Lead Patented

We are offering both oil-hardened and tempered, and lead patented steel wires for mechanical springs.

  • Fine precision
  • Superior surface quality
  • Customizable

JIS G 3521 Hard drawn spring steel wire

Chemical Composition

0.2mm ~ 0.45mm

Wire Grade C Si Mn P S
JIS G 3521 SWB 0.69-0.76 0.15-0.35 0.30-0.60 max0.030 max0.030
0.79-0.86 0.15-0.35 0.60-0.90 max0.030 max0.030
JIS G 3522 SWC 0.69-0.76 0.15-0.35 0.30-0.60 max0.030 max0.030
0.79-0.86 0.15-0.35 0.60-0.90 max0.030 max0.030
0.79-0.86 0.15-0.35 0.30-0.90 max0.030 max0.030

Dimensional Tolerance

Diameter range SWB SWC
Tolerance Roundness
0.15≤D≤0.20 +0/-0.006 max0.003
0.20≤D≤0.50 +0/-0.008 max0.004
0.50≤D≤0.60 +0/-0.010 max0.005
0.60≤D≤1.00 +0.005/-0.010 max0.008
1.00≤D≤2.00 +0.005/-0.015 max0.010

Tensile Strength

JIS G3521 SWB/SWC
Diameter N/mm2
Tensile Strength
SWB SWC
0.15 2210-2550 2550-2890
0.16 2210-2550 2550-2890
0.17 2210-2550 2500-2840
0.18 2210-2550 2500-2840
0.19 2210-2550 2500-2790
0.20 2210-2550 2500-2790
0.25 2110-2400 2400-2700
0.30 2010-2300 2300-2600
0.35 2010-2300 2300-2600
0.40 1960-2260 2260-2550
0.45 1910-2210 2210-2500
0.50 1910-2210 2210-2500
0.55 1860-2160 2160-2450
0.60 1860-2110 2110-2400
0.65 1810-2110 2110-2400
0.70 1770-2060 2060-2350
0.75 1770-2010 2010-2300
0.80 1770-2010 2010-2300
0.85 1770-2010 2010-2260
0.90 1770-2010 2010-2260
0.95 1720-1960 1960-2210
1.00 1720-1960 1960-2210
1.05 1670-1910 1960-2160
1.10 1670-1910 1910-2160
1.15 1670-1910 1910-2160
1.20 1670-1910 1910-2160
1.25 1620-1860 1860-2110
1.30 1620-1860 1860-2110
1.35 1620-1860 1860-2110
1.40 1620-1860 1860-2110
1.45 1570-1810 1810-2060
1.50 1570-1810 1810-2060
1.55 1570-1810 1810-2060
1.60 1570-1810 1810-2060
1.65 1520-1770 1770-2010
1.70 1520-1770 1770-2010
1.75 1520-1770 1770-2010
1.80 1520-1770 1770-2010
1.85 1470-1720 1720-1960
1.90 1470-1720 1720-1960
1.95 1470-1720 1720-1960
2.00 1470-1720 1720-1960
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