Steel 100CrMo7-3 +AR (Hot rolled)
Heat-treated state
EN 100CrMo7-3
Order as-rolled bar or tube as blank stock at 290 HB when you will do your own annealing, forging or post-forge heat treatment in house.
Values for the +AR condition
Other 100CrMo7-3 tempers and conditions
100CrMo7-3 is listed in 8 conditions; see the grade overview at 100CrMo7-3.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Pick the soft (spheroidize) annealed condition, ≤240 HB, the usual delivery state, for turning and cold forming before final quenching and tempering. | 430 | 700 | 18 | 207 HB | 44 W/m·K |
+ARThis page Hot rolled | Order as-rolled bar or tube as blank stock at 290 HB when you will do your own annealing, forging or post-forge heat treatment in house. | 550 | 950 | 10 | 30 HRC | 3.9 % IACS |
Normalized | Use normalizing as an intermediate step after forging to remove carbide networks and refine the structure; spheroidize annealing is still required before machining. | 600 | 1,000 | 9 | 31 HRC | 3.9 % IACS |
Cold drawn | Choose cold drawn bar from spheroidize-annealed stock for precision small-diameter roller and pin blanks; tolerances tighten and hardness rises to 245 HB, formability drops to 20. | 620 | 820 | 10 | 23 HRC | 3.9 % IACS |
Hardened + dimensional-stabilizing temper (S1, ~240 °C), 57–60 HRC | Use the hardened plus S1 stabilizing temper near 240 °C, 57–60 HRC, for bearings working up to 200 °C, trading a little hardness for dimensional stability. | 1,700 | 2,000 | 1.5 | 58 HRC | 3.3 % IACS |
Bainite hardened (austempered), 58–62 HRC | Choose bainite hardening (austempering) at 58–62 HRC for large wind-turbine and rolling-mill bearings: residual compressive stress, toughness and contamination tolerance beat martensitic quenching. | 1,750 | 2,100 | 2 | 60 HRC | — |
Through hardened + tempered ~200 °C, 58–62 HRC | Pick the higher temper near 200 °C for 58–62 HRC when large rings or shock loading need more toughness and dimensional stability than the peak-hardness temper gives. | 1,800 | 2,150 | 1 | 60 HRC | — |
Through hardened + tempered 160–180 °C, 60–64 HRC | Specify oil quenching from 830–860 °C plus tempering at 160–180 °C to 60–64 HRC for finished bearings: peak hardness and contact fatigue life, limited to 150 °C service. | 1,900 | 2,350 | 0.5 | 62 HRC | 34 W/m·K |
What is 100CrMo7-3 +AR?
100CrMo7-3 +AR is 100CrMo7-3 heat treated to +AR — order as-rolled bar or tube as blank stock at 290 HB when you will do your own annealing, forging or post-forge heat treatment in house. 100CrMo7-3 +AR has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 71% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). 100CrMo7-3 +AR has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,400°C (2,552 °F). +A is the default condition FabDigit quotes; +AR is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 85/100, better than 99% of steel grades
Limitations
- Difficult to weld — 12/100, worse than 96% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
100CrMo7-3 +AR properties
Typical room-temperature values for 100CrMo7-3 +AR; 22 are specific to this condition. Other listed values are 100CrMo7-3 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
100CrMo7-3 +AR has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,400°C (2,552 °F).
Mechanical14
100CrMo7-3 +AR has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 71% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
100CrMo7-3 +AR is rated for continuous service to 200°C (392 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
100CrMo7-3 +AR conducts electricity at 3.9 % IACS, worse than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 100CrMo7-3 +AR takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability6
100CrMo7-3 +AR's machinability is poor (30/100, worse than 89% of steel grades); weldability not recommended (12/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 100CrMo7-3 +AR
Is 100CrMo7-3 easy to machine?
Turn only in the spheroidize-annealed condition (<= 240 HB) using coated carbide at low speed and high feed. Once hardened, finish by grinding or CBN hard turning.
Can 100CrMo7-3 be welded?
The high carbon equivalent and crack sensitivity make it non-weldable for practical purposes. Where unavoidable, limit to localized induction or laser welding followed immediately by tempering.
Can 100CrMo7-3 be formed, bent or molded?
Annealed material can be warm forged or cold headed into ring and roller blanks. Re-spheroidize anneal after forming, before hardening.
What surface finishes work on 100CrMo7-3?
The standard route is grinding plus superfinishing, with raceways at Ra 0.05-0.2 µm. Corrosion protection relies on oiling, phosphating or blackening, as the steel has no inherent corrosion resistance.
100CrMo7-3 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 |
|---|---|---|
| C | 0.93 – 1.05 | 0.98 |
| Si | 0.2 – 0.4 | 0.28 |
| Mn | 0.6 – 0.8 | 0.7 |
| Cr | 1.65 – 1.95 | 1.8 |
| MoMo raises hardenability for large sections | 0.2 – 0.35 | 0.3 |
| P | ≤ 0.03 | — |
| S | ≤ 0.02 | — |
| Niresidual, max | ≤ 0.3 | — |
| Curesidual, max | ≤ 0.3 | — |
| Ototal oxygen, max (bearing cleanliness) | ≤ 0 | — |
| Fe | balance | — |
100CrMo7-3 +AR — frequently asked
What is 100CrMo7-3 +AR used for?
100CrMo7-3 +AR is typically used for large bearing rings, rolling mill bearings, wind turbine main bearing rings, large tapered and cylindrical rollers, spherical roller bearing raceways and heavy-section thrust washers. In short: large-section 100Cr6 upgrade; deep-hardening bearing steel; through-hardened raceways.
What is the yield strength of 100CrMo7-3 +AR?
100CrMo7-3 +AR has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 71% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 100CrMo7-3 +AR easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Turn only in the spheroidize-annealed condition (<= 240 HB) using coated carbide at low speed and high feed. Once hardened, finish by grinding or CBN hard turning.
Can 100CrMo7-3 +AR be welded?
Not readily — weldability is rated not recommended (12/100). The high carbon equivalent and crack sensitivity make it non-weldable for practical purposes. Where unavoidable, limit to localized induction or laser welding followed immediately by tempering.
What surface finishes work on 100CrMo7-3 +AR?
The standard route is grinding plus superfinishing, with raceways at Ra 0.05-0.2 µm. Corrosion protection relies on oiling, phosphating or blackening, as the steel has no inherent corrosion resistance.
Can 100CrMo7-3 +AR be formed, bent or molded?
Annealed material can be warm forged or cold headed into ring and roller blanks. Re-spheroidize anneal after forming, before hardening.
What is the maximum service temperature of 100CrMo7-3 +AR?
100CrMo7-3 +AR is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 100CrMo7-3 +A and 100CrMo7-3-BH?
+A is the default condition — pick the soft (spheroidize) annealed condition, ≤240 HB, the usual delivery state, for turning and cold forming before final quenching and tempering. BH: choose bainite hardening (austempering) at 58–62 HRC for large wind-turbine and rolling-mill bearings: residual compressive stress, toughness and contamination tolerance beat martensitic quenching. Yield strength is 430 MPa in +A versus 1,750 MPa in BH.
Sources
- ISO 683-17 Heat-treatable steels — Part 17: Ball and roller bearing steels — ISO (2014)
- DIN EN ISO 683-17 / Werkstoff 1.3536 — DIN (2015)
- GB/T 18254 (GCr18Mo ) — SAC (2016)
- ASM Handbook Vol. 1 — Bearing Steels — ASM International (1990)
- Bearing steel 100CrMo7-3 bar and tube data — Ovako / Sandvik / Chinese bearing-steel mills (2023)
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.