Spring steel
# Spring steel

Spring steel is a name given to a wide range of steels used in the manufacture of different products, including swords, saw blades, springs and many more. These steels are generally low-alloy manganese, medium-carbon steel or high-carbon steel with a very high yield strength. This allows objects made of spring steel to return to their original shape despite significant deflection or twisting.

## Grades

Many grades of steel can be hardened and tempered to increase elasticity and resist deformation; however, some steels are inherently more elastic than others:

Common spring steel grades :

| SAE grade (ASTM grade) | Composition | Yield strength | Hardness (HRC) | Hardness (HRC) | Comments |
| - | - | - | - | - | - |
| SAE grade (ASTM grade) | Composition | Yield strength | Typical | Maximum | Comments |
| 1070 | 0.65-0.75% C, 0.60-0.90% Mn, max .050% S, max .040% P | Normally supplied annealed | 165vpn | 180vpn | CS70, CK67, C70E |
| 1074/1075 | 0.70–0.80% C, 0.50–0.80% Mn, max. 0.030% P, max. 0.035% S | 62–78 ksi (430–540 MPa) | 44–50 | 50 | Scaleless blue, or Polished Bright |
| 1080 (A228) | 0.7–1.0% C, 0.2–0.6% Mn, 0.1–0.3% Si | | | | Piano wire, music wire, springs, clutch discs |
| 1095 (A684) | 0.90–1.03% C, 0.30–0.50% Mn, max. 0.030% P, max. 0.035% S | 60–75 ksi (410–520 MPa), annealed | 48–51 | 59 | Blue, or polished bright spring steel |
| 5160 (A689) | 0.55–0.65% C, 0.75–1.00% Mn, 0.70–0.90% Cr | 97 ksi (670 MPa) | | 63 | Chrome-silicon spring steel; fatigue-resistant |
| 50CrV4 (EN 10277) | 0.47–0.55% C, max. 1.10% Mn, 0.90–1.20% Cr, 0.10–0.20% V, max. 0.40% Si | 170 ksi (1,200 MPa) | | | Old British 735 H1steel, SAE 6150, 735A51 |
| 9255 | 0.50–0.60% C, 0.70–0.95% Mn, 1.80–2.20% Si | | | | |
| 301 spring-tempered stainless steel | 0.08–0.15% C, max. 2.00% Mn, 16.00–18.00% Cr, 6.00–8.00% Ni | 147 ksi (1,010 MPa) | | 42 | Equivalents EN 10088-2 1.4310, X10CrNi18-8 |

## Applications

* Applications include piano wire (also known as music wire) such as ASTM A228 (0.80–0.95% carbon), spring clamps, antennas, springs (e. g. vehicle coil springs or leaf springs), and s-tines.
* Spring steel is commonly used in the manufacture of swords with rounded edges for training or stage combat, as well as sharpened swords for collectors and live combat.
* Spring steel is one of the most popular materials used in the fabrication of lockpicks due to its pliability and resilience.
* Tubular spring steel is used in the landing gear of some small aircraft due to its ability to absorb the impact of landing.
* It is frequently used in the making of knives, machetes, and other edged tools.
* It is a key component in electrician's fish tape.
* It is used in binder clips.
* Used extensively in shims due to its resistance to deformation in low thicknesses.
