Steel ZG20CrMo
ZG20CrMo is a low-carbon 1.25Cr-0.5Mo cast alloy steel supplied as-cast (F), annealed, normalized and tempered, quenched and tempered, or stress relieved.
Reference datasheet — ZG20CrMo is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the N+T condition
ZG20CrMo tempers and conditions
ZG20CrMo is supplied in 5 conditions, soft to hard. N+T is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Choose for maximum machinability and lowest residual stress before heavy machining or repair welding. | 255 | 470 | 24 | 145 HB | 8 % IACS |
As fabricated | Rough/non-pressure parts only; coarse as-cast structure with low toughness — pressure service requires heat treatment. | 260 | 500 | 13 | 170 HB | 7.8 % IACS |
Stress relieved | Applied after weld repair or heavy machining of N+T castings to restore dimensional stability and weld-zone toughness. | 280 | 510 | 22 | 155 HB | 7.8 % IACS |
N+TDefault Normalized and tempered | Standard delivery condition for pressure-vessel and valve castings; balanced strength, toughness and elevated-temperature stability. | 285 | 520 | 21 | 160 HB | — |
Quenched and tempered | Pick when higher yield strength and low-temperature toughness are needed in thinner sections, e.g. high-pressure valve bodies. | 470 | 660 | 17 | 18 HRC | — |
What is ZG20CrMo?
ZG20CrMo is a low-carbon 1.25Cr-0.5Mo cast alloy steel supplied as-cast (F), annealed, normalized and tempered, quenched and tempered, or stress relieved. It is used for pressure-retaining castings — valve bodies, fittings and vessel sections — that need moderate strength at elevated temperature, with a service ceiling of 510 °C. Typical default properties are 285 MPa yield, 520 MPa tensile, 21 % elongation and 160 HB; machinability rates 55 and weldability 62, but sound welds need preheat and post-weld heat treatment. Where 510 °C capability is not required, plain carbon steel castings cost less. ZG20CrMo has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). ZG20CrMo has a yield strength of 285 MPa (41.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 89% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
What is ZG20CrMo used for?
- Valve bodies
- Pressure vessel castings
- Pipe fittings
Advantages
- High service temperature — 510°C (950 °F), better than 92% of steel grades
Limitations
- Low strength — 285 MPa (41.3 ksi), worse than 89% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
ZG20CrMo properties
Typical room-temperature values for ZG20CrMo-N+T; bars are the position among steel grades.
Physical3
ZG20CrMo has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
ZG20CrMo has a yield strength of 285 MPa (41.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 89% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
ZG20CrMo is rated for continuous service to 510°C (950 °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).
Electrical2
ZG20CrMo has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of ZG20CrMo takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 75%.
Manufacturability8
ZG20CrMo's machinability is good (55/100, better than 62% of steel grades); weldability good (62/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. ZG20CrMo is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZG20CrMo
Is ZG20CrMo easy to machine?
Machine in the annealed or N+T condition with coated carbide, moderate speeds and rigid setups; watch for hard spots and sand inclusions in the cast skin.
Can ZG20CrMo be welded?
Weldable with matching 1.25Cr-0.5Mo/E8018-B2-type consumables using 150–250 °C preheat, low-hydrogen practice and 620–680 °C PWHT to avoid HAZ hardening and cracking.
Can ZG20CrMo be formed, bent or molded?
Sand or investment cast with generous risering and 2–3 % shrink allowance; avoid abrupt section changes and heat-treat after gate removal.
ZG20CrMo 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 – 0.25 | 0.21 |
| Si | 0.2 – 0.6 | 0.4 |
| Mn | 0.5 – 0.8 | 0.65 |
| Cr | 0.5 – 0.8 | 0.65 |
| Mo | 0.4 – 0.6 | 0.5 |
| Niresidual | ≤ 0.3 | |
| Curesidual | ≤ 0.3 | |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on ZG20CrMo?
No anodizing; use shot blasting plus epoxy/aluminium-pigment paint, phosphating or metallizing for atmospheric protection, and machine seating faces to seal quality.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
How much does ZG20CrMo cost?
ZG20CrMo is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ZG20CrMo — frequently asked
What is ZG20CrMo used for?
ZG20CrMo is typically used for valve bodies, pressure vessel castings and pipe fittings. In short: cr-Mo casting for 510 °C; weldable pressure-retaining casting; moderate creep strength.
What is the yield strength of ZG20CrMo?
ZG20CrMo has a typical yield strength of 285 MPa (41.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 89% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is ZG20CrMo easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in the annealed or N+T condition with coated carbide, moderate speeds and rigid setups; watch for hard spots and sand inclusions in the cast skin.
Can ZG20CrMo be welded?
Yes — weldability is rated good (62/100). Weldable with matching 1.25Cr-0.5Mo/E8018-B2-type consumables using 150–250 °C preheat, low-hydrogen practice and 620–680 °C PWHT to avoid HAZ hardening and cracking.
What surface finishes work on ZG20CrMo?
No anodizing; use shot blasting plus epoxy/aluminium-pigment paint, phosphating or metallizing for atmospheric protection, and machine seating faces to seal quality.
Can ZG20CrMo be formed, bent or molded?
Sand or investment cast with generous risering and 2–3 % shrink allowance; avoid abrupt section changes and heat-treat after gate removal.
What is the maximum service temperature of ZG20CrMo?
ZG20CrMo is rated for continuous use to about 510°C (950 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZG20CrMo N+T and ZG20CrMo-QT?
N+T is the default condition — standard delivery condition for pressure-vessel and valve castings; balanced strength, toughness and elevated-temperature stability. QT: pick when higher yield strength and low-temperature toughness are needed in thinner sections, e.g. high-pressure valve bodies. Yield strength is 285 MPa in N+T versus 470 MPa in QT.
How much does ZG20CrMo cost?
ZG20CrMo is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A217/A217M (WC1, WC6 Cr-Mo steel castings) — ASTM (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast low-alloy steels) — ASM International (1990)
- Mysteel / 1688 (2026)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.