Steel SUJ2 Hot Rolled
Finish state
JIS SUJ2 · AISI/SAE 52100 · EN 100Cr6, 1.3505 · GB GCr15
Cheapest mill condition for stock that will be spheroidize annealed before machining.
Values for the Hot Rolled condition
Other SUJ2 tempers and conditions
SUJ2 is listed in 7 conditions; see the grade overview at SUJ2.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft, machinable delivery condition | Standard stock condition for bars, tubes and rings that will be machined and then through-hardened. | 420 | 660 | 25 | 192 HB | — |
Hot RolledThis page pearlitic bar/wire | Cheapest mill condition for stock that will be spheroidize annealed before machining. | 600 | 1,000 | 10 | 31 HRC | 7.2 % IACS |
Cold Drawn (annealed + cold drawn bar/wire) | Choose for close-tolerance, bright bar or wire feeding cold-heading and turning operations. | 620 | 790 | 12 | 21 HRC | 7 % IACS |
Hardened + stabilized (extra temper 250–350 °C for dimensional stability) | Use for gauges, spindles and high-temperature bearings that must hold size up to ~200–250 °C, accepting 2–5 HRC lower hardness. | 1,650 | 1,900 | 3.5 | 57 HRC | 6 % IACS |
Tempered ~200–230 °C for slightly higher toughness | Pick when a little more toughness and dimensional stability is wanted at modest hardness loss (shafts, cams, gauge bodies). | 1,750 | 2,050 | 2.5 | 60 HRC | — |
Bainite hardened (isothermal/austempered ~230 °C, 58–61 HRC) | Specified for large or shock-loaded bearing rings needing compressive surface stress, better toughness and lower distortion than martensitic hardening. | 1,800 | 2,100 | 3 | 59 HRC | — |
Quenched and tempered | The functional bearing condition: maximum hardness, wear and rolling-contact fatigue resistance for races, balls and rollers. | 1,900 | 2,280 | 1.5 | 62 HRC | 36 W/m·K |
What is SUJ2 Hot Rolled?
SUJ2 Hot Rolled is SUJ2 supplied in the Hot Rolled condition — cheapest mill condition for stock that will be spheroidize annealed before machining. SUJ2 Hot Rolled has a yield strength of 600 MPa (87 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 77% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). SUJ2 Hot Rolled has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,425°C (2,597 °F). Annealed is the default condition FabDigit quotes; Hot Rolled is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 85/100, better than 99% of steel grades
- High strength — 600 MPa (87 ksi), better than 77% of steel grades
Limitations
- Limited ductility — 10%, worse than 91% of steel grades
- Difficult to machine — 28/100, worse than 91% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
SUJ2 Hot Rolled properties
Typical room-temperature values for SUJ2 Hot Rolled; 22 are specific to this condition. Other listed values are SUJ2 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SUJ2 Hot Rolled has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
SUJ2 Hot Rolled has a yield strength of 600 MPa (87 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 77% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
SUJ2 Hot Rolled is rated for continuous service to 300°C (572 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
SUJ2 Hot Rolled conducts electricity at 7.2 % IACS, worse than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of SUJ2 Hot Rolled takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability8
SUJ2 Hot Rolled's machinability is poor (28/100, worse than 91% of steel grades); weldability poor (15/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SUJ2 Hot Rolled
Is SUJ2 easy to machine?
Machine only in the spheroidize-annealed state (≈40 % of AISI 1212) with rigid setups and carbide tooling; hardened 60+ HRC parts require grinding, honing or CBN hard turning.
Can SUJ2 be welded?
Essentially not weldable — high carbon equivalent causes quench cracking; if unavoidable, preheat 300–400 °C and post-weld temper immediately.
Can SUJ2 be formed, bent or molded?
Cold heading and ring rolling are done from spheroidized stock; hot work 1050–850 °C followed by slow cooling and spheroidize annealing to avoid carbide network.
What surface finishes work on SUJ2?
No anodizing; protect with oil, phosphate, black oxide or thin hard chrome/nickel plating (bake to avoid hydrogen embrittlement), and superfinish raceways for low friction.
SUJ2 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CJIS G 4805 SUJ2 | 0.95 – 1.1 | 1 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | ≤ 0.5 | 0.35 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Cr | 1.3 – 1.6 | 1.45 |
| Ni | ≤ 0.25 | — |
| Cu | ≤ 0.25 | — |
| Mo | ≤ 0.08 | — |
| Otypical clean-steel oxygen limit for bearing quality | ≤ 0 | — |
| Fe | balance | — |
SUJ2 Hot Rolled — frequently asked
What is SUJ2 Hot Rolled used for?
SUJ2 Hot Rolled is typically used for ball bearing rings and balls, roller bearings and rollers, precision shafts and spindles, linear guide rails, cam followers and gauges and measuring blocks. In short: premium bearing tool steel.
What is the yield strength of SUJ2 Hot Rolled?
SUJ2 Hot Rolled has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 77% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is SUJ2 Hot Rolled easy to machine?
Not especially — machinability is rated poor (28/100, worse than 91% of steel grades). Machine only in the spheroidize-annealed state (≈40 % of AISI 1212) with rigid setups and carbide tooling; hardened 60+ HRC parts require grinding, honing or CBN hard turning.
Can SUJ2 Hot Rolled be welded?
Not readily — weldability is rated poor (15/100). Essentially not weldable — high carbon equivalent causes quench cracking; if unavoidable, preheat 300–400 °C and post-weld temper immediately.
What surface finishes work on SUJ2 Hot Rolled?
No anodizing; protect with oil, phosphate, black oxide or thin hard chrome/nickel plating (bake to avoid hydrogen embrittlement), and superfinish raceways for low friction.
Can SUJ2 Hot Rolled be formed, bent or molded?
Cold heading and ring rolling are done from spheroidized stock; hot work 1050–850 °C followed by slow cooling and spheroidize annealing to avoid carbide network.
What is the maximum service temperature of SUJ2 Hot Rolled?
SUJ2 Hot Rolled is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in SUJ2 Hot Rolled?
Yes — SUJ2 Hot Rolled is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- JIS G 4805 High carbon chromium bearing steels — JISC (2019)
- GB/T 18254 High-carbon chromium bearing steel — SAC (2016)
- ASTM A295 Standard Specification for High-Carbon Anti-Friction Bearing Steel — ASTM (2020)
- EN ISO 683-17 (100Cr6) Heat-treatable steels — ball and roller bearing steels — ISO (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- 100Cr6 / SUJ2 bearing steel datasheet — Ovako / Böhler (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.