Steel 20NiCrMoS2-2 +HH
Grade
EN 20NiCrMoS2-2
+HH = restricted hardenability, upper half of the Jominy band
Order for thick sections or when a fully martensitic core is required after oil quenching.
Values for the +HH condition
Other 20NiCrMoS2-2 tempers and conditions
20NiCrMoS2-2 is listed in 10 conditions; see the grade overview at 20NiCrMoS2-2.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ACDefault Spheroidize annealed | Default machining/cold-forming stock: softest condition, best tool life and deep-drilling behaviour before carburizing. | 330 | 510 | 24 | 160 HB | — |
Treated for shearability | Choose for cold-sheared blanks feeding cold heading or upsetting lines. | 350 | 540 | 22 | 170 HB | 8.5 % IACS |
Treated to ferrite–pearlite structure and hardness range | Pick for consistent chip control and surface finish on CNC/auto-lathe turning before carburizing. | 360 | 560 | 20 | 175 HB | — |
Treated to a specified hardness range | Order when the mill must guarantee an as-delivered Brinell window for automated machining lines. | 370 | 560 | 20 | 12 HRC | 8.5 % IACS |
Hot rolled | Cheapest mill condition; buy when you will normalize or anneal in-house before machining. | 400 | 620 | 18 | 190 HB | — |
Spheroidize annealed then cold drawn | Bright, close-tolerance bar for high-volume screw-machine work where straightness and finish matter. | 530 | 660 | 12 | 200 HB | — |
Cold drawn | Standard bright bar when tight diameter tolerance is needed but full spheroidizing is not specified. | 560 | 690 | 11 | 17 HRC | 8.4 % IACS |
Restricted hardenability, lower half of the Jominy band | Use for thin, distortion-sensitive parts where lower core hardness and less quench cracking are wanted. | 620 | 880 | 13 | 59 HRC | 8.2 % IACS |
Guaranteed hardenability band (Jominy); properties after carburize,… | Specify +H when the finished part is carburized and case depth/core strength must be repeatable batch to batch. | 680 | 950 | 11 | 60 HRC | 42 W/m·K |
+HHThis page Restricted hardenability, upper half of the Jominy band | Order for thick sections or when a fully martensitic core is required after oil quenching. | 740 | 1,030 | 10 | 60 HRC | 8 % IACS |
What is 20NiCrMoS2-2 +HH?
20NiCrMoS2-2 +HH is 20NiCrMoS2-2 in the +HH grade — order for thick sections or when a fully martensitic core is required after oil quenching. 20NiCrMoS2-2 +HH has a yield strength of 740 MPa (107 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 83% of steel grades. Elongation at break is 10% and the elastic modulus is 208 GPa (30.2 Msi). 20NiCrMoS2-2 +HH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). +AC is the default condition FabDigit quotes; +HH is available on request or by drawing note.
Advantages
- High strength — 740 MPa (107 ksi), better than 83% of steel grades
Limitations
- Hard to polish — 40/100, 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 — 32/100, worse than 87% of steel grades
- Limited formability — 22/100, worse than 76% of steel grades
20NiCrMoS2-2 +HH properties
Typical room-temperature values for 20NiCrMoS2-2 +HH; 22 are specific to this condition. Other listed values are 20NiCrMoS2-2 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
20NiCrMoS2-2 +HH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
20NiCrMoS2-2 +HH has a yield strength of 740 MPa (107 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 83% of steel grades. Elongation at break is 10% and the elastic modulus is 208 GPa (30.2 Msi).
Thermal6
20NiCrMoS2-2 +HH is rated for continuous service to 200°C (392 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
20NiCrMoS2-2 +HH conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 20NiCrMoS2-2 +HH takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
20NiCrMoS2-2 +HH's machinability is poor (32/100, worse than 87% of steel grades); weldability poor (30/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 20NiCrMoS2-2 +HH
Is 20NiCrMoS2-2 easy to machine?
Excellent for high-volume turning in +AC/+AC+C — MnS breaks chips; run coated carbide at ~180–250 m/min, and finish-grind after carburizing since the hardened case is essentially unmachinable.
Can 20NiCrMoS2-2 be welded?
Weldable in the soft condition with 100–200 °C preheat and low-hydrogen consumables, but the 0.02–0.04 % S raises hot-cracking risk; avoid welding carburized or hardened zones.
Can 20NiCrMoS2-2 be formed, bent or molded?
Cold heads and bends acceptably in +AC (bend radius ≥1.5×t, longitudinal only); hot forge at 1100–1150 °C then normalize at 880–920 °C before machining.
What surface finishes work on 20NiCrMoS2-2?
No anodizing (ferrous) — protect with zinc or Zn-Ni plating, black oxide, phosphate + oil, or QPQ; polished faces show sulfide stringers so avoid this grade for mirror finishes.
20NiCrMoS2-2 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 | 0.17 – 0.23 | 0.2 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.65 – 0.95 | 0.8 |
| P | ≤ 0.04 | 0.02 |
| Sdeliberately resulfurized for machinability | 0.02 – 0.04 | 0.03 |
| Cr | 0.35 – 0.65 | 0.5 |
| Mo | 0.15 – 0.25 | 0.2 |
| Ni | 0.4 – 0.7 | 0.55 |
| Fe | balance | — |
20NiCrMoS2-2 +HH — frequently asked
What is 20NiCrMoS2-2 +HH used for?
20NiCrMoS2-2 +HH is typically used for machined carburized gears, automotive shafts and automatic-lathe components. In short: free-machining carburizing steel; best chip control in family; reduced transverse toughness.
What is the yield strength of 20NiCrMoS2-2 +HH?
20NiCrMoS2-2 +HH has a typical yield strength of 740 MPa (107 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 83% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 20NiCrMoS2-2 +HH easy to machine?
Not especially — machinability is rated poor (32/100, worse than 87% of steel grades). Excellent for high-volume turning in +AC/+AC+C — MnS breaks chips; run coated carbide at ~180–250 m/min, and finish-grind after carburizing since the hardened case is essentially unmachinable.
Can 20NiCrMoS2-2 +HH be welded?
Not readily — weldability is rated poor (30/100). Weldable in the soft condition with 100–200 °C preheat and low-hydrogen consumables, but the 0.02–0.04 % S raises hot-cracking risk; avoid welding carburized or hardened zones.
What surface finishes work on 20NiCrMoS2-2 +HH?
No anodizing (ferrous) — protect with zinc or Zn-Ni plating, black oxide, phosphate + oil, or QPQ; polished faces show sulfide stringers so avoid this grade for mirror finishes.
Can 20NiCrMoS2-2 +HH be formed, bent or molded?
Cold heads and bends acceptably in +AC (bend radius ≥1.5×t, longitudinal only); hot forge at 1100–1150 °C then normalize at 880–920 °C before machining.
What is the maximum service temperature of 20NiCrMoS2-2 +HH?
20NiCrMoS2-2 +HH 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.
Sources
- EN 10084 — Case hardening steels: technical delivery conditions — CEN (2008)
- EN 10277 — Bright steel products: technical delivery conditions — CEN (2018)
- SAE J404 / ASTM A29 — AISI 8620 chemical composition — SAE / ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating (carburizing) — ASM International (2013)
- Machinery's Handbook (machinability ratings) — Industrial Press (2020)
- Case hardening steel bar datasheets (1.6523 / 1.6526 / 8620) — European long-product mills (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.