1.7102
54SiCr6
Si-Cr spring steel for hot-rolled quenched and tempered springs.
Complete introduction and metallurgical analysis
1.7102 / 54SiCr6 belongs to Spring Steels and selection centres on high elastic strength and fatigue resistance under cyclic bending or torsion.
Si-Cr spring steel for hot-rolled quenched and tempered springs.
The principal recorded elements are C≈0.55%, Si≈1.4%, Mn≈0.65%, P≈0.025%, S≈0.025%, Cr≈0.65%. Mid-range values support engineering interpretation and do not replace purchase limits.
The expected microstructure is fine tempered martensite with surface quality and decarburisation under control; delivery condition, section size, melt quality and processing history can change that state.
Comparison indices are hardness 74/100, toughness 66/100, impact 73/100, wear 60/100 and bending 88/100. These are internal indices, not standard test results.
The screening temperature range is 150–300 °C; strength or hardness loss, oxidation, exposure time and creep must be assessed separately.
A representative process route is forming followed by quenching and tempering, with shot peening or presetting where specified. Obtain actual temperatures, times and cooling media from the grade and product data sheet.
Manufacturing indices are weldability 37/100, machinability 55/100, corrosion resistance 18/100 and fatigue resistance 81/100; use them for screening only.
The principal risk is fatigue cracking from surface defects, decarburisation, corrosion or tensile residual stress. Evaluate geometry, surface condition, environment and the governing failure mechanism together.
A similar name or calculated relationship is not proof of interchangeability; match chemistry, specification, condition, heat treatment and MTC.
Engineering conclusion: 1.7102 / 54SiCr6 is a rational candidate when high yield ratio and reliable elastic energy storage matches the real load, environment and certified product condition.
International equivalents and designations
A close counterpart is not automatically interchangeable. Confirm chemistry, product standard, delivery condition, dimensions and heat treatment.
Chemical composition and the role of each element
The principal recorded elements are C≈0.55%, Si≈1.4%, Mn≈0.65%, P≈0.025%, S≈0.025%, Cr≈0.65%. Mid-range values support engineering interpretation and do not replace purchase limits. Composition is shown for screening and traceability. The current purchase standard and the heat-specific MTC remain authoritative.
| Element | Weight-percent range | Metallurgical role and effect |
|---|---|---|
| C | 0.51–0.59 % | Carbon raises hardness, strength and carbide potential; excessive carbon can reduce toughness and weldability. |
| Si | 1.2–1.6 % | Silicon supports deoxidation and solid-solution strength and can influence tempering or oxidation response. |
| Mn | 0.5–0.8 % | Manganese contributes to hardenability and sulfur control; its final effect depends on amount and processing. |
| P | ≤ 0.025 % | Phosphorus is normally restricted because higher content can promote embrittlement and reduce toughness. |
| S | ≤ 0.025 % | Sulfur may improve chip control in free-cutting grades but can reduce transverse toughness and weldability. |
| Cr | 0.5–0.8 % | Chromium promotes hardenability and carbide formation and, at sufficient levels, corrosion or oxidation resistance. |
EN 10089:2002 Sourced with conditions
Engineering behaviour and selection response
Hardness must be reported with delivery/heat-treatment condition; no single grade-wide value applies. Internal comparison index: 74/100.
Engineering analysisToughness has an internal index of 66/100 (high). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisImpact resistance has an internal index of 73/100 (high). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisBending resistance has an internal index of 88/100 (very high). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisWear resistance depends on final hardness, microstructure and wear mode; grade name alone is insufficient for substitution. Internal comparison index: 60/100.
Engineering analysisNot stainless; surface protection is generally required in moist/corrosive service. Internal comparison index: 18/100.
Engineering analysisWeldability has an internal index of 37/100 (low). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisMachinability has an internal index of 55/100 (moderate). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisTemperature-dependent behavior varies with condition, exposure time, environment and product form; use sourced values for design. Internal comparison index: 30/100.
Engineering analysisCreep resistance has an internal index of 12/100 (very low). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisFatigue resistance has an internal index of 81/100 (high). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisNumerical scores are internal comparison indices. They are not standard test results, allowable design stresses or a manufacturer guarantee. Data Method
Hardness and hardenability
Hardness must be reported with delivery/heat-treatment condition; no single grade-wide value applies. Internal screening index: 74/100 (high).
high
Comparison indexGoverning factors
- Chemistry and section size
- Austenitising and quench severity
- Tempering temperature and time
- Test method and surface preparation
Data limits
Final acceptance requires the current standard, product form, dimensions, delivery condition and heat-specific MTC.
Toughness, impact and fracture behaviour
Impact resistance is indexed at 73/100 and toughness at 66/100. These are not Charpy or Izod energy values; temperature, orientation, geometry and actual microstructure govern component behaviour.
- Microstructure, hardness and grain size influence impact tolerance.
- Sharp radii, notches and surface defects reduce fracture resistance.
- Test temperature, specimen direction and section must be identified.
- For critical parts, accept impact energy only from a documented test of the same condition.
Service temperature, thermal stability and creep
Temperature-dependent behavior varies with condition, exposure time, environment and product form; use sourced values for design. 150–300 °C is a screening range or sourced limit according to its evidence label. Check strength loss, oxidation, creep, exposure time and environment.
Continuous service
150–300 °CEngineering guidanceReview the limit against strength or hardness loss and exposure time.
Intermittent service
Do not assign an intermittent limit without product-specific source data.
Tempering and phase stability
Working and coating temperatures must remain compatible with the tempering condition and required microstructure.
Oxidation and environment
Oxidation or corrosion may become limiting before the strength criterion.
The relative creep index is 12/100 (very low). It is not an allowable creep stress or rupture-life value.
Do not select this grade for long-term static high-temperature loading from the internal index alone.
Wear resistance and surface behaviour
Abrasive wear
Wear resistance depends on final hardness, microstructure and wear mode; grade name alone is insufficient for substitution. The abrasive-wear index is 60/100; final hardness, carbides, microstructure, contact mode and lubrication govern actual resistance.
Comparison indexAdhesive wear
Assess adhesive wear with the counterface material, lubrication, roughness, pressure and temperature.
Engineering analysisSurface improvement
Evaluate surface treatment or coating only after confirming compatibility with chemistry, substrate and process temperature.
Engineering guidanceMechanical and physical properties
The record contains 1 sourced mechanical-property rows; each applies only to its stated condition, dimensions and test temperature.
| Property | Value | Condition | Dimension | Test temperature |
|---|---|---|---|---|
| Brinell hardness | ≤ 248 HB | Annealed as cited | According to the product data sheet | According to the cited test |
Physical properties
Heat-treatment stages and process controls
The representative family route is forming followed by quenching and tempering, with shot peening or presetting where specified. Numerical temperatures are shown only when supported by the record.
Heat-treatment stage
850–1150 °CSourced with conditionsConfirm every numerical parameter from the current product and process specification.
Cooling: airHeat-treatment stage
860–890 °CSourced with conditionsConfirm every numerical parameter from the current product and process specification.
Cooling: airQuenching / controlled cooling
800–840 °CSourced with conditionsChoose the quench medium and cooling severity against hardenability, geometry, distortion and crack risk.
Cooling: oil or polymerTempering / property adjustment
380–500 °CSourced with conditionsSet tempering or ageing to the required hardness, toughness and service-temperature balance.
Cooling: airAnnealing / stress relief
670–720 °CSourced with conditionsAssess the supply condition, residual stress, section size and prior machining before selecting time and temperature.
Cooling: controlledAnnealing / stress relief
Engineering guidanceAssess the supply condition, residual stress, section size and prior machining before selecting time and temperature.
Cooling: Grade- and process-specific coolingPreheating and austenitising
Engineering guidanceSet preheat steps and austenitising parameters from the grade/product data sheet and actual section size.
Cooling: Grade- and process-specific coolingQuenching / controlled cooling
Engineering guidanceChoose the quench medium and cooling severity against hardenability, geometry, distortion and crack risk.
Cooling: Grade- and process-specific coolingTempering / property adjustment
Engineering guidanceSet tempering or ageing to the required hardness, toughness and service-temperature balance.
Cooling: Grade- and process-specific coolingTempering / property adjustment
Engineering guidanceSet tempering or ageing to the required hardness, toughness and service-temperature balance.
Cooling: Grade- and process-specific coolingHardness, toughness, impact, temperature and process charts
Chemistry data retain their evidence label; 0–100 charts are internal indices and stages without temperature are process sequences.
Multi-axis engineering profile
Comparison indexChemical composition
Derived from source dataHardness–toughness balance
Comparison indexToughness, impact and fatigue
Comparison indexWear and surface response
Comparison indexMechanical properties or comparison indices
Sourced with conditionsService temperature
Engineering guidanceHeat treatment
Sourced with conditionsRelated-grade similarity
Comparison indexAll comparison indices
Comparison indexPotential failure modes and selection guidance
Potential failure mechanisms
- fatigue cracking from surface defects, decarburisation, corrosion or tensile residual stress.
- Fatigue initiation from surface defects, section transitions or stress concentration.
- Property loss after unsuitable heat treatment, cooling or finishing.
- Corrosion, oxidation or environmental attack when protection is inadequate.
Selection and design notes
- Match designation, material number, product standard and supply form before purchase.
- Compare the governing failure mechanism with hardness 74, toughness 66, impact 73 and wear 60 indices out of 100.
- Use mechanical values only within their cited condition, dimensions and test temperature.
- Confirm the heat-treatment route and target hardness with the processor before final machining.
- Review the heat number, MTC and required test results before release.
Derived calculations
Calculated from recorded inputs; apply only within the stated formula scope and limitations.
Advantages, limitations and unsuitable applications
Advantages
- high yield ratio and reliable elastic energy storage.
- A clearly labelled engineering profile supports comparison with related grades.
- Grade identity, chemistry, counterparts and references remain traceable in one dossier.
Limitations and weaknesses
- fatigue cracking from surface defects, decarburisation, corrosion or tensile residual stress.
- A 0–100 index cannot be converted into design stress, impact energy or creep life.
- Hardness and toughness depend on section, delivery condition and actual processing.
- Do not approve a substitute before checking the product standard and heat-specific MTC.
Cases requiring caution or an alternative material
Industrial applications and processing
Typical applications
- High-strength fasteners and mechanical connections
- Coil, leaf and torsion springs or resilient components
- coil and leaf springs
- stabiliser and torsion bars
- spring washers and elastic elements
- fatigue-loaded vehicle and machine components
Manufacture, welding and surface engineering
Weldability has an internal index of 37/100 (low). Actual performance requires a documented product condition, heat treatment and test context.
Forming and forging depend on steel family, delivery condition and the grade-specific qualified temperature range.
- Select nitriding, induction hardening or coating against chemistry, substrate hardness and application.
- Keep coating-deposition temperature compatible with the tempering condition and substrate.
- Control hydrogen embrittlement, residual stress and distortion in high-strength components.
Engineering conclusion and selection recommendation
1.7102 / 54SiCr6 is worth evaluating when the principal need is high yield ratio and reliable elastic energy storage. Internal indices of hardness 74/100, toughness 66/100, impact 73/100 and wear 60/100 must be aligned with the real failure mechanism. The leading risk is fatigue cracking from surface defects, decarburisation, corrosion or tensile residual stress. Final approval requires the current standard, product form, dimensions, delivery condition, heat treatment and heat-specific MTC.
Engineering analysisFrequently asked questions
What is 1.7102 / 54SiCr6 steel?
Si-Cr spring steel for hot-rolled quenched and tempered springs.
What are the main applications of 1.7102 / 54SiCr6?
Application contexts include High-strength fasteners and mechanical connections, Coil, leaf and torsion springs or resilient components, coil and leaf springs and stabiliser and torsion bars, subject to the product standard and actual condition.
How hard can 1.7102 / 54SiCr6 be?
Hardness must be reported with delivery/heat-treatment condition; no single grade-wide value applies. Internal screening index: 74/100 (high).
Is 1.7102 / 54SiCr6 suitable for impact loading?
Impact resistance is indexed at 73/100 and toughness at 66/100. These are not Charpy or Izod energy values; temperature, orientation, geometry and actual microstructure govern component behaviour.
What is the service-temperature limit of 1.7102 / 54SiCr6?
Temperature-dependent behavior varies with condition, exposure time, environment and product form; use sourced values for design. 150–300 °C is a screening range or sourced limit according to its evidence label. Check strength loss, oxidation, creep, exposure time and environment.
Can 1.7102 / 54SiCr6 be replaced by a close grade?
Approve substitution only after matching chemistry, specification, product form, condition, heat treatment and MTC.
Engineering steel comparison
Compare this grade with any other dossier. Scores from 0 to 100 are internal screening indices, not laboratory values or allowable design stresses.
Current-grade chemistry
Second-grade chemistry
Current-grade heat treatment
Second-grade heat treatment
Current-grade applications
Limitations
Second-grade applications
Limitations
Select a second grade to update the comparison.
Sources, methodology and evidence
Sources support grade identity, recorded values or the engineering method. General guidance does not replace product-specific certification.
Grade-specific sources
Reference supporting grade identity or recorded values; interpret it within the cited product and condition context. Role: technical.
Reference supporting grade identity or recorded values; interpret it within the cited product and condition context. Role: technical.
Reference supporting grade identity or recorded values; interpret it within the cited product and condition context. Role: official material number register.
Methodology and analysis sources
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Dossier reviewed: 2026-08-25 · Evidence status: Sourced numerical data plus engineering analysis
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