The PN-EN 10089:2005 standard is titled: "Hot-rolled steels for heat-treated springs - Technical delivery conditions ." This is a European technical standard that specifies the delivery requirements for spring steels intended for the production of springs and elastic elements that are subjected to heat treatment.
The PN-EN 10089:2005 standard replaced the earlier PN-EN 10089:2003 standard , which was withdrawn on 23 June 2005.
Previously, the PN-EN 10089:2003 standard replaced the Polish PN-H-93003:1996 standard.
Scope of the PN-EN 10089:2005 standard
The PN-EN 10089:2005 standard applies to hot-rolled, heat-treated steels intended for the production of:
- Flat and spiral springs.
- Car and railway springs.
- High-strength elastic elements.
It does not include steel intended for the production of spring wires, cold-rolled strips and special springs.
Division and classification of steel according to PN-EN 10089:2005
The standard divides spring steels according to their chemical composition and mechanical properties, taking into account alloying elements such as:
- Carbon (C) – affects the hardness and elasticity of steel.
- Silicon (Si) – improves elasticity and resistance to tempering.
- Chromium (Cr) – increases hardenability and corrosion resistance.
- Vanadium (V) – improves resistance to fatigue and cracking.
- Molybdenum (Mo) – increases creep resistance and strength at high temperatures.
- Nickel (Ni) – increases hardenability and corrosion resistance.
Examples of steel grades according to PN-EN 10089:
38Si7 (1.5023)
Silicon steel with medium elasticity and good fatigue resistance. Designed for lightweight springs and components with moderate dynamic loads.
46Si7 (1.5024)
Silicon steel with increased hardness and mechanical strength compared to 38Si7. Used in the production of flat and spiral springs subjected to higher loads.
56Si7 (1.5026)
Highly elastic silicon steel, characterized by good resistance to permanent deformation. Used in suspension springs in motor vehicles.
54SiCr6 (1.7102)
Silicon-chromium steel with high hardness and abrasion resistance. Especially recommended for automotive springs and components subject to dynamic loads.
56SiCr7 (1.7106)
Steel with increased silicon and chromium content, resulting in increased hardness and durability. It is used in springs for large vehicles and machinery.
61SiCr7 (1.7108)
Highly resilient steel with increased resistance to cracking and fatigue. Designed for components requiring the highest strength requirements.
52SiCrNi5 (1.7117)
Silicon-chromium-nickel steel, combining high strength with increased corrosion resistance. Used in springs operating in harsh environmental conditions.
55Cr3 (1.7176)
Chrome steel with high hardness and good abrasion resistance. Used in automotive leaf springs and springs with high dynamic loads.
60Cr3 (1.7177)
Very hard chrome steel, designed for components requiring exceptional durability and resistance to deformation. Used in springs and coil springs in commercial vehicles.
60CrMo3-1 (1.7239)
Chromium-molybdenum steel, resistant to creep at elevated temperatures. Used in springs operating in high-temperature environments.
60CrMo3-2 (1.7240)
Steel with increased chromium and molybdenum content, providing improved hardenability and abrasion resistance. Used in springs for industrial applications.
60CrMo3-3 (1.7241)
High-alloy chromium-molybdenum steel with maximum creep resistance and high hardness. Designed for components operating under extreme temperatures and pressures.
52CrMoV4 (1.7701)
Chrome-molybdenum-vanadium steel with exceptional fatigue and fracture resistance. Designed for highly stressed components such as torsion bars and suspension springs.
46SiCrMo6 (1.8062)
Silicon-chromium-molybdenum steel with an excellent balance of hardness and elasticity. Used in passenger car suspension springs.
50SiCrMo6 (1.8063)
A steel with increased hardness and elasticity compared to 46SiCrMo6. Ideal for producing springs with high dynamic loads, such as sports suspensions.
45SiCrV6-2 (1.8151)
Silicon-chromium-vanadium steel with increased resistance to cracking and wear. Used in high-cyclic-durability springs.
54SiCrV6 (1.8152)
A steel with very high hardness and excellent fatigue resistance. Used in industrial springs and components subjected to prolonged loading.
60SiCrV7 (1.8153)
The most resilient silicon-chromium-vanadium steel in this group, with exceptional durability and resistance to permanent deformation. Used in specialized industrial springs.
51CrV4 (1.8159)
Chrome-vanadium steel with excellent elastic properties, high hardness, and fracture resistance. Commonly used in automotive leaf springs and suspension springs.
Mechanical properties of steels covered by the PN-EN 10089:2005 standard
The standard specifies minimum requirements for the mechanical properties of steel, such as:
- Yield strength (Re) – the minimum stress value after which the material undergoes permanent deformation.
- Tensile strength (Rm) – the maximum force that a material can withstand before breaking.
- Hardness (HB or HRC) – material resistance to penetration.
- Impact strength (KV) – resistance to dynamic loads.
These properties are determined after heat treatment.
Delivery conditions and heat treatment
The standard also defines requirements for the heat treatment process, which includes:
- Hardening – heating to a certain temperature and rapid cooling to increase hardness.
- Letting go – heating to a lower temperature to reduce brittleness and increase elasticity.
Steel supplied in accordance with PN-EN 10089 shall be supplied in the hot-rolled and heat-treated condition or in the condition ready for heat treatment.
Dimensional and shape tolerances
The standard also specifies permissible dimensional deviations for bars and wire rods, including:
- Diameter and thickness of the material.
- Straightness.
- Surface roughness.
Standard PN-EN 10089:2005 marking and certification
Each batch of steel covered by the standard should be supplied with appropriate documentation, which includes:
- Designation of steel grade in accordance with the standard.
- Batch number and production date.
- Certificate of conformity confirming compliance with the standard.
Use of steel according to PN-EN 10089:2005
Steels covered by the standard are used in the production of:
- Car and railway springs.
- Suspension springs.
- Springs exposed to high dynamic loads.
- Mechanical components requiring high resistance to fatigue and abrasion.
The PN-EN 10089:2005 standard establishes uniform quality standards for spring steels used in Europe, specifying chemical composition, mechanical properties, and heat treatment methods. This enables the production of materials with high elasticity, durability, and fatigue resistance, which is crucial for automotive, railway, and industrial applications.