Steel G20Mo5 +A (Annealed)
Heat-treated state
EN 1.5419
Full-anneal condition used to soften castings for heavy machining or repair welding before final heat treatment.
Values for the +A condition
Other G20Mo5 tempers and conditions
G20Mo5 is listed in 4 conditions; see the grade overview at G20Mo5.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+AThis page Annealed | Full-anneal condition used to soften castings for heavy machining or repair welding before final heat treatment. | 250 | 460 | 28 | 135 HB | 8.7 % IACS |
Normalized | Normalized only; used for thinner non-pressure or lightly loaded castings where no tempering is specified. | 270 | 490 | 24 | 145 HB | 8.6 % IACS |
+N+TDefault Normalized and tempered | Default pressure-casting condition: normalize ~900–940 °C, temper 620–680 °C for stable 245 MPa min yield and 27 J toughness. | 285 | 510 | 25 | 150 HB | — |
Quenched and tempered | Choose for heavy-section castings needing uniform properties, higher yield and better low-temperature toughness. | 330 | 550 | 23 | 170 HB | — |
What is G20Mo5 +A?
G20Mo5 +A is G20Mo5 heat treated to +A — full-anneal condition used to soften castings for heavy machining or repair welding before final heat treatment. G20Mo5 +A has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 94% of steel grades. Elongation at break is 28% and the elastic modulus is 210 GPa (30.5 Msi). G20Mo5 +A 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). +N+T is the default condition FabDigit quotes; +A is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 28%, better than 89% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
- High service temperature — 450°C (842 °F), better than 86% of steel grades
- Readily welded — 72/100, better than 75% of steel grades
Limitations
- Low strength — 250 MPa (36.3 ksi), worse than 94% of steel grades
- Limited formability — 18/100, worse than 84% of steel grades
G20Mo5 +A properties
Typical room-temperature values for G20Mo5 +A; 22 are specific to this condition. Other listed values are G20Mo5 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
G20Mo5 +A 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
G20Mo5 +A has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 94% of steel grades. Elongation at break is 28% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
G20Mo5 +A is rated for continuous service to 450°C (842 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical2
G20Mo5 +A has an electrical resistivity of 1.98×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of G20Mo5 +A takes about 27 MJ of energy and emits 2.2 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 75%.
Manufacturability8
G20Mo5 +A's machinability is good (62/100, better than 89% of steel grades); weldability very good (72/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with G20Mo5 +A
Is G20Mo5 easy to machine?
Machines like normalized 4130-class steel — use carbide at 120–180 m/min, expect variable skin hardness and sand inclusions on unblasted casting surfaces.
Can G20Mo5 be welded?
P-No.3 material: SMAW/GTAW/SAW with 1.25Cr–0.5Mo or C-Mo filler (E7018-A1), preheat 150–200 °C and PWHT 620–680 °C for pressure-boundary and repair welds.
Can G20Mo5 be formed, bent or molded?
Supplied as sand or investment castings; keep uniform wall thickness with generous risers and 2–3 % shrinkage allowance, then normalize/temper the whole casting.
What surface finishes work on G20Mo5?
No inherent corrosion resistance — shot blast then epoxy/zinc-rich paint, aluminium metallizing or phosphating; anodizing is not applicable.
G20Mo5 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 |
|---|---|---|
| CEN 10213; ASTM A352 LC1 allows ≤0.25 | 0.15 – 0.23 | 0.19 |
| Si | ≤ 0.6 | 0.35 |
| MnA352 LC1: 0.50–0.80 | 0.5 – 1 | 0.75 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.02 | 0.01 |
| Mo | 0.4 – 0.6 | 0.5 |
| Crresidual | ≤ 0.3 | 0.1 |
| Niresidual | ≤ 0.4 | 0.15 |
| Curesidual | ≤ 0.3 | 0.1 |
| Vresidual | ≤ 0.03 | 0.01 |
| Fe | balance | — |
G20Mo5 +A — frequently asked
What is G20Mo5 +A used for?
G20Mo5 +A is typically used for valve bodies, pump casings and high-temperature piping fittings. In short: carbon-moly pressure casting; service to 450 °C; weldable P-No.3 casting.
What is the yield strength of G20Mo5 +A?
G20Mo5 +A has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 94% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is G20Mo5 +A easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines like normalized 4130-class steel — use carbide at 120–180 m/min, expect variable skin hardness and sand inclusions on unblasted casting surfaces.
Can G20Mo5 +A be welded?
Yes — weldability is rated very good (72/100). P-No.3 material: SMAW/GTAW/SAW with 1.25Cr–0.5Mo or C-Mo filler (E7018-A1), preheat 150–200 °C and PWHT 620–680 °C for pressure-boundary and repair welds.
What surface finishes work on G20Mo5 +A?
No inherent corrosion resistance — shot blast then epoxy/zinc-rich paint, aluminium metallizing or phosphating; anodizing is not applicable.
Can G20Mo5 +A be formed, bent or molded?
Supplied as sand or investment castings; keep uniform wall thickness with generous risers and 2–3 % shrinkage allowance, then normalize/temper the whole casting.
What is the maximum service temperature of G20Mo5 +A?
G20Mo5 +A is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- ASTM A352/A352M — Steel Castings, Ferritic and Martensitic, for Pressure-Containing Parts for Low-Temperature Service (Gr. LC1) — ASTM (2018)
- ASTM A217/A217M — Steel Castings, Martensitic Stainless and Alloy, for Pressure-Containing Parts (Gr. WC1) — ASTM (2021)
- GB/T 16253 — (ZG20Mo) — SAC (2019)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Castings Handbook, 6th ed. — SFSA / ASM International (1995)
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.