Case Hardening Steels Official identity plus labelled composition estimate
Material / Grade
1.7271
23CrMoB3-3
1.7271 / 23CrMoB3-3 is independently listed in the official European steel material-number register; property indices and designation-derived chemistry are clearly labelled screening guidance.
Steel Overview
Complete introduction and metallurgical analysis
1.7271 / 23CrMoB3-3 belongs to Case Hardening Steels and selection centres on a hard wear-resistant case combined with a tougher load-bearing core.
1.7271 / 23CrMoB3-3 is independently listed in the official European steel material-number register; property indices and designation-derived chemistry are clearly labelled screening guidance.
The principal recorded elements are C≈0.23%, Cr≈0.75%, Mo≈0.3%. Mid-range values support engineering interpretation and do not replace purchase limits.
The expected microstructure is a high-carbon martensitic case over a lower-carbon tough core after carburising, quenching and tempering; delivery condition, section size, melt quality and processing history can change that state.
Comparison indices are hardness 86/100, toughness 73/100, impact 70/100, wear 83/100 and bending 75/100. These are internal indices, not standard test results.
The screening temperature range is 0–200 °C; strength or hardness loss, oxidation, exposure time and creep must be assessed separately.
A representative process route is carburising or carbonitriding followed by grade-specific hardening, quenching, tempering and case-depth verification. Obtain actual temperatures, times and cooling media from the grade and product data sheet.
Manufacturing indices are weldability 42/100, machinability 57/100, corrosion resistance 20/100 and fatigue resistance 84/100; use them for screening only.
The principal risk is case cracking, distortion, retained austenite or inadequate effective case depth when the cycle is not controlled. 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: 1.7271 / 23CrMoB3-3 is a rational candidate when high surface hardness and contact-wear resistance without sacrificing core toughness matches the real load, environment and certified product condition.
Recorded standards:DIN EN 10027-2 — steel material-number systemDIN EN 10027-1 — steel designation systemEuropean Steel Registration Office / Stahldaten
International Equivalents
International equivalents and designations
A close counterpart is not automatically interchangeable. Confirm chemistry, product standard, delivery condition, dimensions and heat treatment.
W.NrOfficial designation for the same grade
1.7271A registered identity within the same grade record.
DIN / EN official registerOfficial designation for the same grade
23CrMoB3-3A registered identity within the same grade record.
Chemical Composition
Chemical composition and the role of each element
The principal recorded elements are C≈0.23%, Cr≈0.75%, Mo≈0.3%. 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 | ≈ 0.23 % | Carbon raises hardness, strength and carbide potential; excessive carbon can reduce toughness and weldability. |
| Cr | ≈ 0.75 % | Chromium promotes hardenability and carbide formation and, at sufficient levels, corrosion or oxidation resistance. |
| Mo | ≈ 0.3 % | Molybdenum improves hardenability and temper resistance and can support hot strength or pitting resistance. |
DIN EN 10027-1 — steel designation system Designation estimate
Engineering Behaviour
Engineering behaviour and selection response
Hardness potential86 / 100
Relative hardness screening index only; verify actual condition, section size and treatment. Internal comparison index: 86/100.
Engineering analysisToughness73 / 100
Toughness has an internal index of 73/100 (high). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisImpact resistance70 / 100
Impact resistance has an internal index of 70/100 (high). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisBending resistance75 / 100
Bending resistance has an internal index of 75/100 (high). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisAbrasive wear83 / 100
Wear screening depends on microstructure, hardness, counterface and lubrication. Internal comparison index: 83/100.
Engineering analysisCorrosion resistance20 / 100
Corrosion resistance depends on actual chemistry, condition, surface and exposure environment. Internal comparison index: 20/100.
Engineering analysisWeldability42 / 100
Weldability has an internal index of 42/100 (low). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisMachinability57 / 100
Machinability has an internal index of 57/100 (moderate). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisHigh-temperature strength33 / 100
The stated range is family screening guidance, not a sourced service limit. Internal comparison index: 33/100.
Engineering analysisCreep resistance20 / 100
Creep resistance has an internal index of 20/100 (very low). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisFatigue resistance84 / 100
Fatigue resistance has an internal index of 84/100 (very 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 & Hardenability
Hardness and hardenability
Relative hardness screening index only; verify actual condition, section size and treatment. Internal screening index: 86/100 (very high).
86/100
very 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.
Impact & Toughness
Toughness, impact and fracture behaviour
Impact resistance is indexed at 70/100 and toughness at 73/100. These are not Charpy or Izod energy values; temperature, orientation, geometry and actual microstructure govern component behaviour.
70/100highComparison index
- 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.
Temperature & Creep
Service temperature, thermal stability and creep
The stated range is family screening guidance, not a sourced service limit. 0–200 °C is a screening range or sourced limit according to its evidence label. Check strength loss, oxidation, creep, exposure time and environment.
Continuous service
0–200 °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.
Relative creep resistance20/100Comparison index
The relative creep index is 20/100 (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 & Surface Behaviour
Wear resistance and surface behaviour
Abrasive wear
Wear screening depends on microstructure, hardness, counterface and lubrication. The abrasive-wear index is 83/100; 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 & Physical Properties
Mechanical and physical properties
No complete sourced numerical mechanical set is stored for this condition; labelled comparison indices are shown instead of invented test values.
| Comparative property | Internal index | Information type |
|---|---|---|
| Hardness potential | 86 / 100 | Comparison index |
| Toughness | 73 / 100 | Comparison index |
| Impact resistance | 70 / 100 | Comparison index |
| Bending resistance | 75 / 100 | Comparison index |
| Abrasive wear | 83 / 100 | Comparison index |
| Corrosion resistance | 20 / 100 | Comparison index |
| Weldability | 42 / 100 | Comparison index |
| Machinability | 57 / 100 | Comparison index |
| High-temperature strength | 33 / 100 | Comparison index |
| Creep resistance | 20 / 100 | Comparison index |
| Fatigue resistance | 84 / 100 | Comparison index |
Physical properties
Density, elastic modulus, expansion and conductivity depend on family, temperature and product condition. Use grade- and product-specific values for precise calculations.
- Obtain density and expansion data from the product data sheet for dimensional calculations.
- Elastic modulus and conductivity vary with temperature.
Heat Treatment
Heat-treatment stages and process controls
The representative family route is carburising or carbonitriding followed by grade-specific hardening, quenching, tempering and case-depth verification. Numerical temperatures are shown only when supported by the record.
Annealing / 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 coolingProcess control: Review delivery condition, actual section, equipment capability, crack and distortion risk and target hardness before approving the cycle.
Engineering Charts
Hardness, 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
Designation estimateHardness–toughness balance
Comparison indexToughness, impact and fatigue
Comparison indexWear and surface response
Comparison indexMechanical properties or comparison indices
Comparison indexService temperature
Engineering guidanceHeat treatment
Engineering guidanceRelated-grade similarity
Comparison indexAll comparison indices
Comparison indexFailure Modes & Selection
Potential failure modes and selection guidance
Potential failure mechanisms
- case cracking, distortion, retained austenite or inadequate effective case depth when the cycle is not controlled.
- 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 86, toughness 73, impact 70 and wear 83 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.
Advantages & Limitations
Advantages, limitations and unsuitable applications
Advantages
- high surface hardness and contact-wear resistance without sacrificing core toughness.
- A clearly labelled engineering profile supports comparison with related grades.
- Grade identity, chemistry, counterparts and references remain traceable in one dossier.
Limitations and weaknesses
- case cracking, distortion, retained austenite or inadequate effective case depth when the cycle is not controlled.
- 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
Applications & Processing
Industrial applications and processing
Typical applications
- Gears and power-transmission components
- Pinions and highly loaded gear-train parts
- gears and pinions
- case-hardened shafts and bushings
- transmission and drive components
- wear-loaded parts requiring a tough core
Manufacture, welding and surface engineering
Weldability has an internal index of 42/100 (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
Engineering conclusion and selection recommendation
1.7271 / 23CrMoB3-3 is worth evaluating when the principal need is high surface hardness and contact-wear resistance without sacrificing core toughness. Internal indices of hardness 86/100, toughness 73/100, impact 70/100 and wear 83/100 must be aligned with the real failure mechanism. The leading risk is case cracking, distortion, retained austenite or inadequate effective case depth when the cycle is not controlled. Final approval requires the current standard, product form, dimensions, delivery condition, heat treatment and heat-specific MTC.
Engineering analysisShaygan Steel — the right choice in alloy steelFrequently Asked Questions
Frequently asked questions
What is 1.7271 / 23CrMoB3-3 steel?
1.7271 / 23CrMoB3-3 is independently listed in the official European steel material-number register; property indices and designation-derived chemistry are clearly labelled screening guidance.
What are the main applications of 1.7271 / 23CrMoB3-3?
Application contexts include Gears and power-transmission components, Pinions and highly loaded gear-train parts, gears and pinions and case-hardened shafts and bushings, subject to the product standard and actual condition.
How hard can 1.7271 / 23CrMoB3-3 be?
Relative hardness screening index only; verify actual condition, section size and treatment. Internal screening index: 86/100 (very high).
Is 1.7271 / 23CrMoB3-3 suitable for impact loading?
Impact resistance is indexed at 70/100 and toughness at 73/100. These are not Charpy or Izod energy values; temperature, orientation, geometry and actual microstructure govern component behaviour.
What is the service-temperature limit of 1.7271 / 23CrMoB3-3?
The stated range is family screening guidance, not a sourced service limit. 0–200 °C is a screening range or sourced limit according to its evidence label. Check strength loss, oxidation, creep, exposure time and environment.
Can 1.7271 / 23CrMoB3-3 be replaced by a close grade?
Approve substitution only after matching chemistry, specification, product form, condition, heat treatment and MTC.
Steel Comparison
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.
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Current-grade chemistry
Second-grade chemistry
Current-grade heat treatment
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Current-grade applications
Limitations
Second-grade applications
Limitations
Select a second grade to update the comparison.
Sources & Evidence
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
stahldaten.deOfficial material-number register · Tier A
View sourceReference supporting grade identity or recorded values; interpret it within the cited product and condition context. Role: official material number register.
VDEh — European Steel Registration OfficeRegistration Authority · Tier A
View sourceReference supporting grade identity or recorded values; interpret it within the cited product and condition context. Role: registration authority.
Methodology and analysis sources
DIN EN 10027 — Numbering and designation framework / European Steel Registration Office
View sourceReference supporting the calculation method or the limits of the engineering analysis.
Ovako Steel Navigator — Heat treatment and engineering steel data
View sourceReference supporting the calculation method or the limits of the engineering analysis.
Outokumpu — Stainless corrosion resistance methodology
View sourceReference supporting the calculation method or the limits of the engineering analysis.
TWI — Carbon equivalent and hydrogen cracking
View sourceReference supporting the calculation method or the limits of the engineering analysis.
Dossier reviewed: 2026-08-25 · Evidence status: Official identity plus labelled composition estimate
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