Steel SCM822-HR (Hot rolled)
Supply condition
JIS SCM822
Cheapest mill condition for parts that will be fully heat treated anyway; hardness scatter and mill scale must be turned off.
Values for the HR condition
Other SCM822 tempers and conditions
SCM822 is listed in 8 conditions; see the grade overview at SCM822.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Choose for cold-forged/upset gear blanks and CVJ parts where maximum cold formability is needed before carburizing. | 400 | 640 | 26 | 175 HB | 8 % IACS |
ADefault Solution annealed | Standard stocked condition: soft, uniform structure for turning, hobbing and shaping before carburizing. | 460 | 720 | 21 | 14 HRC | 8 % IACS |
HRThis page Hot rolled | Cheapest mill condition for parts that will be fully heat treated anyway; hardness scatter and mill scale must be turned off. | 560 | 850 | 16 | 24 HRC | 8 % IACS |
Normalized | Used to refine and homogenise forged blanks and reduce carburizing distortion; harder than annealed. | 560 | 830 | 18 | 23 HRC | 8 % IACS |
Cold drawn | Bright, close-tolerance small-diameter bar for automatic-lathe pinion and shaft blanks. | 700 | 830 | 11 | 24 HRC | 8 % IACS |
Quenched and tempered | Direct-hardened condition used for shafts and non-carburized parts, and the JIS acceptance condition for core strength (≥1030 MPa). | 930 | 1,130 | 14 | 33 HRC | — |
Carburized and hardened | The service condition for gears: hard wear-resistant case with a tough 35–45 HRC core; properties below are case values, tensile data refer to the core. | 1,000 | 1,250 | 11 | 60 HRC | — |
Carburized, hardened and shot peened | Pick for maximum tooth-root bending fatigue on highly loaded transmission gears; peening adds compressive residual stress in the case. | 1,050 | 1,230 | 11 | 61 HRC | 7 % IACS |
What is SCM822-HR?
SCM822-HR is SCM822 supplied in the HR condition — cheapest mill condition for parts that will be fully heat treated anyway; hardness scatter and mill scale must be turned off. SCM822-HR has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 73% of steel grades. Elongation at break is 16% and the elastic modulus is 206 GPa (29.9 Msi). SCM822-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). A is the default condition FabDigit quotes; HR is available on request or by drawing note.
Limitations
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 75% of steel grades
SCM822-HR properties
Typical room-temperature values for SCM822-HR; 23 are specific to this condition. Other listed values are SCM822 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SCM822-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical17
SCM822-HR has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 73% of steel grades. Elongation at break is 16% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
SCM822-HR is rated for continuous service to 350°C (662 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
SCM822-HR conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of SCM822-HR takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
SCM822-HR's machinability is fair (48/100, worse than 57% of steel grades); weldability poor (30/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SCM822-HR
Is SCM822 easy to machine?
Machine in the annealed/normalized state with coated carbide at moderate speeds; leave 0.1–0.3 mm stock for post-carburizing grinding since the 58–62 HRC case is grind-only.
Can SCM822 be welded?
Not intended for welding — high Cr+Mo hardenability gives brittle martensite; if unavoidable, preheat 250–350 °C, use low-hydrogen consumables and temper immediately, and never weld carburized surfaces.
Can SCM822 be formed, bent or molded?
Hot forge 1150–900 °C then normalize or anneal; spheroidize-annealed stock cold-forges well for gear and CVJ blanks.
What surface finishes work on SCM822?
Grind or hard-turn after case hardening, then shot peen for fatigue; protect bare surfaces with oil, phosphate, black oxide or Zn/Mn coating — the steel has no inherent corrosion resistance.
SCM822 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 4053 | 0.2 – 0.25 | 0.22 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Cr | 0.9 – 1.2 | 1.05 |
| Mohigher Mo than SCM420 — main distinguishing element | 0.35 – 0.45 | 0.4 |
| Niresidual | ≤ 0.25 | — |
| Curesidual | ≤ 0.3 | — |
| Fe | balance | — |
SCM822-HR — frequently asked
What is SCM822-HR used for?
SCM822-HR is typically used for transmission gears, differential gears, ring and pinion sets, gearbox shafts and pinion shafts, constant-velocity joint blanks and splined drive couplings. In short: nickel-free carburizing steel; high Cr-Mo hardenability; gear-grade case toughness.
What is the yield strength of SCM822-HR?
SCM822-HR has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 73% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is SCM822-HR easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Machine in the annealed/normalized state with coated carbide at moderate speeds; leave 0.1–0.3 mm stock for post-carburizing grinding since the 58–62 HRC case is grind-only.
Can SCM822-HR be welded?
Not readily — weldability is rated poor (30/100). Not intended for welding — high Cr+Mo hardenability gives brittle martensite; if unavoidable, preheat 250–350 °C, use low-hydrogen consumables and temper immediately, and never weld carburized surfaces.
What surface finishes work on SCM822-HR?
Grind or hard-turn after case hardening, then shot peen for fatigue; protect bare surfaces with oil, phosphate, black oxide or Zn/Mn coating — the steel has no inherent corrosion resistance.
Can SCM822-HR be formed, bent or molded?
Hot forge 1150–900 °C then normalize or anneal; spheroidize-annealed stock cold-forges well for gear and CVJ blanks.
What is the maximum service temperature of SCM822-HR?
SCM822-HR is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SCM822-A and SCM822-CH?
A is the default condition — standard stocked condition: soft, uniform structure for turning, hobbing and shaping before carburizing. CH: the service condition for gears: hard wear-resistant case with a tough 35–45 HRC core; properties below are case values, tensile data refer to the core. Yield strength is 460 MPa in A versus 1,000 MPa in CH.
Sources
- JIS G 4053 — Low-alloyed steels for machine structural use — Japanese Standards Association (2016)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4A/4D — Steel Heat Treating / Carburizing — ASM International (2014)
- Machinery's Handbook, 31st ed. (machinability and heat-treat data) — Industrial Press (2020)
- GB/T 3077 — Alloy structural steels (comparison of 22CrMo-type grades) — SAC (2015)
- (Mysteel / SMM / 1688 ) — Mysteel, SMM (2026)
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.