52100 Steel Explained:Composition, Hardness & Real Uses
52100 is the classic high-carbon chromium bearing steel—but the grade name alone does not create bearing life. This guide connects chemistry, carbide condition, heat treatment, cleanliness, hardness, grinding and service environment so engineers, buyers and knife makers can specify the material that actually reaches the intended performance.
Rolling-contact components
Rings, balls and rollers benefit from the grade's high-carbon chromium chemistry, hardenable matrix and controlled carbide population.
About 61 HRC—not one fixed value
Ovako publishes 61 HRC as a typical martensitic quenched-and-tempered condition. Finished targets still depend on product, section, stability and specification.
Buying chemistry without quality
Inclusions, carbide banding, decarburization, annealed structure and traceability can matter more than a familiar grade label.
Not stainless or easy to weld
Roughly 1.5% chromium promotes hardenability and carbides, not stainless corrosion resistance. High carbon makes welding crack-sensitive.
What is 52100 steel?
52100 steel is a high-carbon chromium alloy developed around the needs of through-hardened rolling bearings. Its nominal chemistry is close to 1% carbon and 1.5% chromium. After controlled austenitizing, quenching and tempering, it can form a very hard martensitic matrix with dispersed carbides—an effective combination for rolling-contact fatigue, wear and dimensional accuracy.
“52100,” “100Cr6,” “1.3505,” “SUJ2” and “GCr15” are often treated as equivalents, but they are better understood as cross-reference starting points. Their governing standards, product forms, impurity limits, hardenability rules, test methods and delivery conditions can differ. A purchase order must name the current standard and required condition rather than saying only “52100 equivalent.”
ISO 683-17:2023 places 100Cr6 among through-hardening bearing steels with about 1% carbon and 1–2% chromium. ASTM A295/A295M covers high-carbon bearing-quality steel for anti-friction bearings and addresses not just chemistry, but also annealed hardness, spheroidization, carbide condition, decarburization and surface imperfections.
Carbon and chromium build the platform—process builds the property.
The representative limits below are the EN ISO 683-17 composition published by Ovako for 100Cr6. They are useful for understanding the alloy, not a substitute for the applicable SAE, ASTM, ISO, EN, JIS or customer specification.
| Element | Representative range, mass % | What it contributes | What still must be controlled |
|---|---|---|---|
| Carbon (C) | 0.93–1.05 | Enables high martensitic hardness and supplies carbon for iron/chromium carbides. | Austenite carbon, undissolved carbide fraction, retained austenite, cracking and decarburization. |
| Chromium (Cr) | 1.35–1.60 | Increases hardenability and participates in carbide stability and wear response. | It is far below stainless levels; corrosion protection is still required. |
| Manganese (Mn) | 0.25–0.45 | Supports hardenability and deoxidation. | Segregation and inclusion morphology remain quality concerns. |
| Silicon (Si) | 0.15–0.35 | Acts as a deoxidizer and affects tempering response. | Supplier variants may reduce silicon for cold-forming performance. |
| Phosphorus (P) | 0.025 max. | No intentional performance benefit in this application. | Low residual levels support toughness and quality consistency. |
| Sulfur (S) | 0.015 max. | Controlled sulfur can improve machinability in special variants. | Sulfide inclusions can conflict with high-fatigue requirements; quality route matters. |
| Molybdenum (Mo) | 0.10 max. | A residual/limited addition under this reference chemistry. | Do not confuse standard 52100 with higher-hardenability ASTM A485 grades. |
The SAE/AISI number communicates an alloy family, not inclusion rating, oxygen level, melt practice, product form, carbide structure, annealed condition or final hardness. Bearing life demands those details. Ask for the mill certificate and the product-quality evidence that matches the design.
Useful numbers with boundaries.
These are producer reference values, not universal design allowables. Ovako lists about 210 HB in a spheroidized condition and 61 HRC in a typical martensitic quenched-and-tempered condition; Carpenter publishes density and elastic constants for its premium E52100 product.
High-carbon chemistry supports hardness and carbide formation.
Promotes hardenability and carbides, not stainless behavior.
Ovako reference—not a blanket drawing requirement.
Converted from Carpenter's 0.2830 lb/in³ value.
Why 52100 works—and where the explanation usually stops too early.
Each property is conditional. Hardness, fatigue and wear come from an interacting system of melt quality, carbide population, heat treatment, grinding, residual stress, geometry, lubrication and operating temperature.
High indentation and contact resistance
A martensitic heat treatment can place 52100 above 60 HRC. That supports raceway contact and edge stability, but maximum hardness is not automatically maximum life.
Verify: target range, location, method and temper condition.Strong rolling-contact potential
The alloy is proven in rings, balls and rollers. NASA emphasizes that hardness, retained austenite, grain size, carbide size and steel processing all influence rolling fatigue.
Verify: cleanliness, microstructure, surface and application load.Hard matrix plus carbides
Carbides resist abrasion and help maintain a cutting edge. Poor carbide networks, banding or coarse particles can instead become stress raisers and reduce reliability.
Verify: spheroidization, carbide rating and final microstructure.Useful, but not impact-steel behavior
Fine structure and controlled tempering can provide a practical wear/toughness balance. At high hardness, however, 52100 remains notch- and crack-sensitive compared with lower-carbon steels.
Verify: geometry, section transitions and impact requirement.Retained austenite must be managed
Phase transformation after grinding or during service can alter size and residual stress. Precision bearings may require stabilization routes beyond a basic harden-and-temper cycle.
Verify: service temperature, stability treatment and final dimensions.A hard surface can still hide the wrong structure.
52100 performance comes from a controlled martensitic or bainitic matrix, dispersed carbides, suitable retained austenite, fine grain size and very low populations of harmful inclusions. Hardness alone cannot reveal all five.
The critical steel is in the contact path
Rings, raceways and rolling elements repeatedly carry localized contact. Steel quality, geometry, lubrication and surface finish work as one system.
Image: Niabot / Wikimedia Commons, CC BY-SA.Five microstructural questions
- Are carbides spheroidized before machining? ASTM A295 addresses carbide size, network and lamellar content when annealing is ordered.
- How much carbide dissolves during austenitizing? Temperature and time change matrix carbon, remaining carbides, grain growth and retained austenite.
- Is the hardened matrix martensitic or bainitic? Both routes exist, with different hardness, ductility, distortion and stability behavior.
- Are inclusions small and well distributed? Fatigue-critical procurement may require cleaner steel, ultrasonic inspection or special melting.
- Was the final surface damaged? Grinding burn, tensile residual stress, white layers, decarburization and dents can erase good bulk metallurgy.
Metallography must come from the actual heat, condition and part location. Published images are useful for learning phase morphology, but release decisions require representative preparation, etching, magnification and an agreed rating method such as ASTM A892 where applicable.
The grade creates potential. Clean steel converts it into life.
NASA's bearing-steel reviews show that processing variables can outweigh nominal chemistry in rolling-contact performance.
Why inclusions matter
Rolling contact creates cyclic subsurface shear stress. A hard inclusion, soft inclusion, void or cluster can disturb the local stress field and become a fatigue initiation site. That is why “bearing quality” is not marketing decoration: melting route, deoxidation, casting, reduction, inclusion control and inspection must match the reliability target.
Why carbides matter
Carbides provide wear resistance, restrict grain growth and store alloying elements for the austenitizing response. But large primary carbides, carbide networks and severe banding create local heterogeneity. ASTM research on commercial A295 52100 reports that casting and rolling variables, reduction and thermal processing influence carbide banding.
Why surface condition matters
Modern clean steels shift more attention toward surface-initiated damage. Dents from debris, poor superfinish, corrosion pits, grinding burn and lubricant-film breakdown can dominate service life even when the bulk steel is excellent. A material certificate cannot replace control of filtration, lubrication, handling and finishing.
Why one fatigue number is misleading
Bearing life is statistical and depends on contact stress, geometry, residual stress, hardness pairing, lubricant, film ratio, temperature, contamination and test method. Published stress or cycle figures describe a defined experiment—not a universal 52100 limit. Use the bearing designer's life calculation and qualification plan for the actual assembly.
Separate the industrial route from the knife-shop recipe.
Producer data provide useful starting windows, but dimensions, furnace atmosphere, prior carbide structure, load size, quench equipment and specification determine the validated cycle. A blade schedule should not be copied onto a bearing ring.
Spheroidize anneal
Softening carbides into a controlled spheroidized distribution improves machining and prepares a repeatable hardening response. Confirm hardness, carbide structure and decarburization.
Machine with allowance
Rough-machine the annealed material, preserve traceability and leave stock for heat movement, decarb removal and final grinding. Avoid deep tool marks at critical transitions.
Austenitize and quench
Ovako lists 830–870°C for its 100Cr6 variants followed by oil quenching for a martensitic route. The qualified window must control carbide dissolution, grain size and distortion.
Temper—and qualify cold treatment if needed
Temper promptly to achieve the hardness/toughness/stability target. Precision service may justify stabilization or cold treatment, but it must be integrated with tempering and dimensional evidence.
Grind, superfinish and inspect
Final size, roundness and roughness are produced after hardening. Monitor grinding temperature and inspect for burn, cracks, residual-stress damage and surface discontinuities.
Martensite is a phase—not a complete acceptance result
This educational micrograph is AISI 4140, not 52100. Actual 52100 qualification must evaluate its own matrix, carbides, retained austenite and grain condition.
Image: Scm83x / Wikimedia Commons, CC BY-SA 3.0.Industrial bearing route vs. blade route
For bearings: follow the current material and bearing specification, qualified furnace load, atmosphere, quench, temper/stabilization and final inspection plan. Hardness distribution, retained austenite, carbide rating, dimensions and surface integrity may all be release criteria.
For knives: use known new bar stock and a heat-treatment schedule developed for the actual thickness, furnace accuracy, atmosphere protection, quench oil, edge geometry and desired balance. Published “1475°F for ten minutes” recipes are not universal, and recycled bearing parts may not actually be 52100.
For both: temperature uniformity, thermocouple accuracy, soak definition, decarburization protection and prompt tempering are more important than copying a single target number from an article.
52100 application & condition planner
Choose the closest scenario. This tool organizes the next specification and validation questions; it does not replace design analysis, a qualified heat-treatment procedure or supplier approval.
Strong fit—if bearing quality is specified
Start with an applicable 52100/100Cr6 bearing-steel specification, then define cleanliness, carbide condition, heat treatment, hardness/stability and final surface evidence for the actual contact.
Manufacture the annealed steel; protect the hardened surface.
Carpenter recommends a spheroidized structure for most machining and reports machinability of roughly 37–45% of B1112 for its annealed VIM-VAR product, depending on bar condition. Those figures are reference data—not universal speeds.
Before hardening
- Confirm incoming condition. Spheroidized annealed 52100 is the normal machining starting point; as-rolled or partially annealed stock can behave very differently.
- Use rigidity and chip control. High carbon/chromium content produces more tool demand than free-machining steel. Continuous stringy chips may require deliberate chip-breaking strategy.
- Leave controlled finish allowance. Predict distortion from geometry, stock removal and furnace loading; do not leave excessive grinding stock that raises burn risk.
- Protect critical surfaces. Avoid deep feed marks, laps and sharp transitions that survive into heat treatment.
After hardening
- Grinding is a metallurgical operation. Excess heat can retemper or reaustenitize the surface, create white layers, tensile residual stress and cracks.
- Control wheel condition and coolant. Dressing, wheel grade, infeed, spark-out and coolant delivery must match the hardened condition and tolerance.
- Inspect more than size. Combine dimensional metrology with surface roughness, burn/crack detection and microstructural or residual-stress checks when risk requires.
- Handle as a precision surface. Dents, corrosion and contamination can become contact-fatigue initiators after all prior metallurgy has passed.
Three limits that change the material decision.
52100 is optimized for hard, clean rolling contact—not fabrication convenience, wet corrosion or continuous high-temperature strength.
Welding: possible in special cases, poor as a default design route
Near-1% carbon and chromium-enhanced hardenability make 52100 highly susceptible to a hard heat-affected zone, quench cracking and hydrogen-assisted cracking. Fusion welding can also destroy the carefully qualified bearing microstructure and dimensional state. New designs that require routine welding usually deserve a more weldable material or a mechanical joining strategy.
If repair welding is unavoidable, it requires engineering authority, base-condition identification, qualified procedure development, controlled hydrogen, preheat/interpass planning, heat-input and cooling control, post-weld heat treatment where appropriate, hardness/microstructure verification, NDE and a decision about whether original fatigue life can be restored. Laser welding is not exempt from these metallurgical constraints merely because its heat input can be localized.
Corrosion: chromium does not make it stainless
52100 will rust when bare steel is exposed to moisture, condensation, salts or washdown. Oil, grease, dry storage, controlled packaging, coatings or a corrosion-resistant bearing material may be required. Corrosion pits are especially serious on raceways because they disturb contact and can initiate surface fatigue.
Temperature: stability and hardness have limits
Conventional 52100 is widely used at ordinary bearing temperatures, but elevated service can reduce hardness and alter dimensions if the steel was not stabilized above the operating temperature. SKF notes that other steels are used when stainless or high-temperature performance is required. For sustained hot service, compare dedicated bearing grades such as M50 or other approved materials rather than assuming a higher temper alone solves every issue.
Applications that exploit hardness, fatigue and wear.
The strongest uses match the alloy's bearing DNA. Secondary uses can work well when geometry, heat treatment, corrosion and impact conditions remain compatible.
| Application | Why 52100 is considered | Condition focus | Watch-out |
|---|---|---|---|
| Ball and roller bearing rings | Rolling-contact fatigue, high hardness, wear and precision finish. | Bearing quality, carbide control, hardening/stability, grinding and superfinish. | Inclusions, debris dents, grinding burn, lubrication and thermal growth. |
| Balls and rollers | High contact strength and polished rolling surface. | Clean steel, sphere/roller geometry, hardness pairing and very low roughness. | Surface discontinuities, laps, decarb, impact damage and contamination. |
| Precision gauges and wear parts | High hardness, wear resistance and dimensional potential. | Stable heat treatment, finishing allowance and metrology. | Brittle geometry, corrosion and post-treatment dimensional change. |
| Knives and cutting tools | Fine edge potential and strong wear/toughness balance for a simple alloy. | Known stock, controlled carbide condition, protected heat treatment and appropriate temper. | Rust, chipping at thin geometry, decarb and unverified recycled bearings. |
| Mandrels, punches and high-hardness machine parts | Strength and wear in compact sections. | Section response, notch control and target hardness/toughness. | Impact overload, welding requirements and oversized sections. |
Choose against the failure mode—not a popularity chart.
The “stronger” steel depends on corrosion, contact type, section, temperature, toughness, wear mechanism, manufacturability and available quality route. These comparisons are decision prompts, not universal rankings.
| Comparison | 52100 advantage | Alternative advantage | Decision question |
|---|---|---|---|
| 52100 vs 1095 | Chromium improves hardenability; bearing-quality routes can offer tightly controlled cleanliness and carbides. | 1095 is simpler and can be attractive for thin blades or tools where deep hardening and bearing quality are unnecessary. | Is the part a thin cutting tool or a contact-fatigue component, and what quality evidence is available? |
| 52100 vs O1 | Strong bearing pedigree, high hardness and good edge potential with controlled processing. | O1 is a recognized oil-hardening tool steel with its own tooling supply chain and heat-treatment practice. | Are you buying a bearing specification or a tool-steel specification, and which heat-treatment provider is qualified? |
| 52100 vs D2 | Generally finer carbide potential and a different toughness/edge-stability balance. | D2 has much higher chromium and a larger carbide volume for strong abrasive wear resistance; it is still not truly corrosion-proof. | Is edge stability/toughness or high abrasive wear the dominant requirement? |
| 52100 vs 440C | Classic noncorrosive-environment bearing performance and broad availability. | 440C offers martensitic stainless corrosion resistance for wet or corrosive environments, with different fatigue and toughness trade-offs. | Can the assembly remain lubricated and protected, or is corrosion resistance a first-order requirement? |
| 52100 vs M50 | Cost-effective, proven bearing steel for conventional temperatures. | M50 is designed for higher-temperature aerospace bearing service and retains useful hot hardness. | What are the stabilized operating and transient temperatures? |
| 52100 vs 8620 / case-hardening steel | High hardness through the responsive section and straightforward through-hardening concept. | Carburized low-carbon cores can provide a hard case with a tougher core for shock, large sections or crack-arrest needs. | Does the component need through hardness or a hard case over a tough core? |
Excellent potential, but not “magic bearing steel.”
Knife performance comes from verified stock, heat treatment, blade geometry, finish and maintenance. A bearing race is not automatically a known, homogeneous or safe starting billet.
Control the thermal history
Forging, normalization, spheroidization, decarburization protection, austenitizing, quenching and tempering all influence the final edge.
Image: katchoo2cc / Wikimedia Commons, CC BY 2.0.A practical knife-maker checklist
- Use certified new bar when repeatability matters. Scrap bearings may be 52100, 100Cr6, stainless, carburized steel or another alloy—and may contain service damage.
- Protect against decarburization. A soft, carbon-depleted surface at the edge can ruin apparent heat-treatment results.
- Match austenitizing to prior structure. Spheroidized bar, forged stock and heavily cycled stock do not necessarily need the same soak.
- Temper for geometry and use. A thin kitchen edge, outdoor knife and impact tool require different chipping/toughness margins.
- Do not copy test charts blindly. CATRA and impact results depend on the exact heat treatment, geometry, finish and test procedure.
- Plan corrosion care. Clean and dry the blade; use food-safe protection where relevant.
“Equivalent” is a comparison task, not a substitution sentence.
Start with the drawing and governing market, then reconcile composition, quality, delivery condition and testing.
ASTM A295/A295M
The active ASTM listing is A295/A295M-14(2020), covering high-carbon anti-friction bearing steel. Its scope reaches beyond chemistry to requirements such as annealed condition, carbide structure, decarburization and surface imperfections. Optional supplementary requirements must be stated when needed.
SAE J404
SAE J404 defines chemical compositions for SAE alloy steels and the product forms to which its tables apply. Chemistry identification does not automatically confer ASTM bearing quality. If a design calls for 52100 under J404, separately define the product, quality, heat treatment and inspection evidence.
ISO 683-17:2023 / 100Cr6 / 1.3505
ISO 683-17 specifies delivery requirements for several groups of bearing steels, including through-hardening, case-hardening, induction-hardening, stainless and high-temperature grades. 100Cr6 is the common international cross-reference, but verify the exact limits and delivery condition before substitution.
Premium and aerospace routes
Carpenter lists AMS 6440, AMS 6444 and ASTM A295 for its premium VIM-VAR E52100 product. That does not mean ordinary commercial 52100 automatically meets an AMS melt route, inspection or quality requirement. State the exact current material specification and revision.
When standard 52100 lacks hardenability
Ovako notes a finite hardenability response for 100Cr6, approximately corresponding to a ring with a maximum 17 mm wall thickness in its reference context. For larger controlling sections, do not assume full core transformation. ASTM A485/A485M covers modified high-hardenability anti-friction bearing steels; case-hardening or induction-hardening routes may also fit the design better.
Specify evidence—not just “52100 bar.”
A strong purchase order tells the mill, distributor, heat treater and machine shop what condition and performance must be delivered. Requirements should be proportional to risk.
State ASTM, SAE, ISO, EN, AMS, JIS or customer specification plus exact grade and any supplementary requirements.
Bar, wire, tube, ring, forging or finished bearing geometry changes hardenability, sampling and delivery requirements.
Commercial, bearing quality, premium clean or VIM-VAR should follow the design basis—not be inferred after purchase.
Spheroidized annealed hardness, carbide rating, surface condition, straightness and decarburization limits affect machining and hardening.
Require heat/lot identification, MTRs and continuity through cutting, heat treatment, grinding and final release.
State range, location and method; add retained austenite, carbide, grain or case/core requirements where applicable.
Specify roughness, decarburization, grinding-burn/crack inspection, NDE, corrosion protection and handling.
State operating temperature, thermal cycling, final grinding sequence, stabilization treatment and metrology timing.
Prohibit unauthorized weld repair, blending, reheat treatment or source substitution; define engineering deviation authority.
Bearing fatigue, knife edge life and wear performance depend on geometry, finish, load, lubrication and environment—not coupons alone.
Validate the actual 52100 surface before production.
Oceanplayer can review laser cleaning and permanent marking on representative 52100/100Cr6 material. For laser welding, the alloy's high carbon and hardened condition require metallurgical review and a qualified acceptance plan; a clean-looking bead is not proof that bearing fatigue or crack resistance survived.
- Material standard, grade, melt route and certificate
- Annealed, hardened, tempered or finished condition
- Part geometry, thickness and critical surface
- Oxide, oil, coating or marking requirement
- Hardness, microstructure and fatigue acceptance
- Production volume and cycle-time target
52100 steel FAQ
Short answers for engineers, buyers, machinists and knife makers. Final release must follow the current governing specification and representative process evidence.
What is 52100 steel?
52100 is a high-carbon chromium alloy best known as a through-hardening bearing steel. Its chemistry is near 1% carbon and 1.5% chromium. Controlled heat treatment creates a hard matrix with carbides for rolling-contact fatigue and wear.
What is the composition of 52100 steel?
Composition depends on the governing standard. As one representative reference, EN ISO 683-17 100Cr6 published by Ovako contains 0.93–1.05% C, 1.35–1.60% Cr, 0.25–0.45% Mn and 0.15–0.35% Si, with controlled residual limits. Check the exact SAE, ASTM or ISO purchase specification.
How hard is 52100 steel?
There is no single required hardness for every application. Ovako publishes about 61 HRC as typical for a martensitic quenched-and-tempered 100Cr6 condition, while annealed spheroidized material is around 210 HB typical. Bearings, knives and wear parts may use different qualified ranges.
Is 52100 steel stainless?
No. Around 1.5% chromium improves hardenability and carbide behavior but is far below the alloy level needed for stainless corrosion resistance. Bare 52100 can rust and commonly needs lubrication, dry storage or another protection strategy.
Is 52100 the same as 100Cr6?
100Cr6/1.3505 is the common international cross-reference to SAE 52100, and their chemistry is broadly similar. They are not automatic substitutes without checking the current standards, product form, impurity limits, quality level, delivery condition and inspection requirements.
Can 52100 steel be welded?
It is a difficult, crack-sensitive welding material because of its high carbon and hardenability. Routine welded fabrication is usually better designed with another steel. Any repair or laser welding needs engineering approval, a qualified procedure, thermal and hydrogen control, heat-treatment planning and inspection.
Is 52100 good knife steel?
Yes, verified 52100 bar can produce excellent cutting tools with a fine edge and useful wear/toughness balance. Results depend on stock condition, decarburization protection, heat treatment, geometry and maintenance. Scrap bearings should not be assumed to be known 52100.
What is the best heat treatment for 52100 steel?
There is no universal best cycle. Producer and specification routes depend on section, prior carbide structure, furnace, atmosphere, quench, required matrix, retained austenite, hardness, stability and distortion. Industrial bearings and knife blades require different validation plans.
Is 52100 through-hardening in every section?
No. “Through-hardening bearing steel” describes the steel group and intended route, not unlimited section capability. Core transformation depends on wall thickness, austenitizing, grain size and quench severity. Larger sections may need A485 high-hardenability steel, case hardening or another approved route.
What should I specify when buying 52100 steel?
State the current standard and revision, product form, exact grade and quality/melt route, dimensions, spheroidized condition and carbide requirements, decarburization, final heat treatment and hardness, microstructure/stability, surface integrity, NDE, certification, traceability and repair rules.
Continue from material selection to process validation.
Use the next resource that matches the decision: cleaning a precision steel surface, selecting laser equipment, marking a traceability code or validating a representative sample.
Standards and primary references.
This guide prioritizes standards organizations, bearing manufacturers, steel producers and government technical literature. Confirm the current revision and contractual requirements before design or release.
- ASTM A01.28 active standards list: A295/A295M-14(2020) for high-carbon anti-friction bearing steel and related bearing-steel standards.
- ASTM A295/A295M-14(2020): chemistry, annealed hardness/spheroidization, decarburization and surface-quality framework.
- ASTM A485-17(2022): high-hardenability modifications of high-carbon bearing-quality steel.
- ISO 683-17:2023: delivery requirements for through-hardening, case-hardening, induction-hardening, stainless and high-temperature bearing steels.
- SAE J404_200901: chemical compositions and applicable product-form scope for SAE alloy steels.
- Ovako 100Cr6 material data: chemistry, conditions, typical properties, heat-treatment recommendations, variants and similar designations.
- Carpenter Technology — CarTech 52100 Alloy: VIM-VAR E52100 description, typical physical properties, heat-treatment and machinability reference data.
- SKF Rolling Bearings catalogue: bearing components and 100Cr6 as the standard steel for rings and washers.
- NASA TM-88881: effects of hardness, retained austenite, grain size, carbides and processing on rolling-element fatigue life.
- NASA/TM-2012-217445: historical and technical review of rolling bearing steels, cleanliness, retained austenite, hardness and temperature.
- ASTM STP paper on carbide banding in A295 52100: influence of casting, reduction and thermal processing on carbide heterogeneity.
- ASTM STP paper on 52100 microstructure and dented contact: retained austenite and damage-tolerance context.