Steel A842 Grade 450
ASTM A842 Grade 450 · EN EN-GJV-450 · GB RuT450 · ISO 16112 JV/450
Compacted graphite iron with worm-like graphite morphology, providing strength and stiffness between gray and ductile iron along with good thermal conductivity and damping, favored for high-output diesel engine blocks.
Reference datasheet — A842 Grade 450 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 AS-CAST condition
A842 Grade 450 tempers and conditions
A842 Grade 450 is supplied in 4 conditions, soft to hard. AS-CAST is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress relieved | Pick for large or dimensionally critical castings (engine blocks, machine bases) to remove casting residual stress before finish machining, with only a small strength loss. | 340 | 470 | 1.8 | 20 HRC | 2.2 % IACS |
AS-CASTDefault pearlitic, no heat treatment (ASTM A842 requires Grade 450 as-cast) | Standard supply condition for Grade 450; alloying (Cu/Sn/Mn) gives a ~100 % pearlitic matrix straight from the mold. | 350 | 490 | 1.5 | 22 HRC | 2.2 % IACS |
Induction hardened | Choose when cylinder bores, seats or guideways need local wear resistance; the pearlitic matrix responds well to induction hardening while the bulk keeps as-cast properties. | 350 | 490 | 1.2 | 52 HRC | 2.2 % IACS |
Normalized | Used when as-cast section size gives too much free ferrite; normalizing restores/raises pearlite content, strength and hardness at the cost of a little ductility and thermal conductivity. | 390 | 530 | 1.2 | 25 HRC | 2.1 % IACS |
What is A842 Grade 450?
Compacted graphite iron with worm-like graphite morphology, providing strength and stiffness between gray and ductile iron along with good thermal conductivity and damping, favored for high-output diesel engine blocks. A842 Grade 450 has a density of 7.15 g/cm³ (0.258 lb/in³), lighter than 99% of steel grades. It melts at 1,150°C (2,102 °F). A842 Grade 450 has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 74% of steel grades. Elongation at break is 1.5% and the elastic modulus is 150 GPa (21.8 Msi).
What is A842 Grade 450 used for?
- diesel engine blocks
- cylinder heads
- exhaust manifolds
- brake components
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
Limitations
- Limited ductility — 1.5%, worse than 99% of steel grades
- Limited formability — 3/100, worse than 99% of steel grades
- Low stiffness — 150 GPa (21.8 Msi), worse than 98% of steel grades
- Low electrical conductivity — 2.2 % IACS, worse than 98% of steel grades
- Low fracture toughness — 25 MPa·√m (22.8 ksi·√in), worse than 97% of steel grades
A842 Grade 450 properties
Typical room-temperature values for A842 Grade 450-AS-CAST; bars are the position among steel grades.
Physical3
A842 Grade 450 has a density of 7.15 g/cm³ (0.258 lb/in³), lighter than 99% of steel grades. It melts at 1,150°C (2,102 °F).
Mechanical16
A842 Grade 450 has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 74% of steel grades. Elongation at break is 1.5% and the elastic modulus is 150 GPa (21.8 Msi).
Thermal6
A842 Grade 450 is rated for continuous service to 400°C (752 °F). It conducts heat at 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 73% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
A842 Grade 450 conducts electricity at 2.2 % IACS, worse than 98% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of A842 Grade 450 takes about 22 MJ of energy and emits 1.9 kg of CO₂ — less than 99% of steel grades. Typical recycled content is 90%.
Manufacturability7
A842 Grade 450's machinability is fair (35/100, worse than 84% of steel grades); weldability poor (25/100); formability not recommended (3/100).
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. A842 Grade 450 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A842 Grade 450
Is A842 Grade 450 easy to machine?
Machinable but far more abrasive on tools than gray iron — use CBN/ceramic or coated carbide at reduced speed, avoid interrupted dry cuts, and expect the shortest tool life in continuous turning/boring.
Can A842 Grade 450 be welded?
Only repair welding: preheat 300–400 °C, NiFe or Ni electrodes, short stringer beads with peening and slow cooling to avoid a hard, cracked HAZ.
Can A842 Grade 450 be formed, bent or molded?
Green sand or shell molding with tight Mg/Ti and inoculation control (thermal analysis feedback); the compacted-graphite window is narrow so nodularity must be held below ~20 %.
A842 Grade 450 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 |
|---|---|---|
| CASTM A842 does not fix composition; typical foundry practice | 3.1 – 3.9 | 3.6 |
| Si | 1.8 – 2.8 | 2.3 |
| Mnhigher end promotes pearlite for Grade 450 | 0.2 – 0.8 | 0.5 |
| Cupearlite stabilizer | 0.3 – 1 | 0.7 |
| Snoptional pearlite promoter | 0 – 0.1 | 0.04 |
| Mgresidual; narrow window controls compacted graphite | 0.01 – 0.03 | 0.01 |
| Tianti-nodularizer in some Ti-based processes | 0 – 0.05 | 0.01 |
| P | ≤ 0.06 | 0.03 |
| Smust be low before Mg treatment | ≤ 0.03 | 0.01 |
| Fe | balance | — |
What surface finishes work on A842 Grade 450?
No anodizing; protect with phosphate + oil, e-coat or paint. Nitriding and induction hardening work on the pearlitic matrix; polishing is limited by graphite pull-out.
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
Equivalent designations
Standards and trade names that resolve to Steel A842 Grade 450 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- EN-GJV-450
- ISO
- 16112 JV/450
- GB (China)
- RuT450
- Also called
- CGI
How much does A842 Grade 450 cost?
A842 Grade 450 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.
A842 Grade 450 — frequently asked
What is A842 Grade 450 used for?
A842 Grade 450 is typically used for diesel engine blocks, cylinder heads, exhaust manifolds and brake components. In short: between gray and ductile iron; high-output diesel block iron; shortest tool life in family.
What is the yield strength of A842 Grade 450?
A842 Grade 450 has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 74% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is A842 Grade 450 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Machinable but far more abrasive on tools than gray iron — use CBN/ceramic or coated carbide at reduced speed, avoid interrupted dry cuts, and expect the shortest tool life in continuous turning/boring.
Can A842 Grade 450 be welded?
Not readily — weldability is rated poor (25/100). Only repair welding: preheat 300–400 °C, NiFe or Ni electrodes, short stringer beads with peening and slow cooling to avoid a hard, cracked HAZ.
What surface finishes work on A842 Grade 450?
No anodizing; protect with phosphate + oil, e-coat or paint. Nitriding and induction hardening work on the pearlitic matrix; polishing is limited by graphite pull-out.
Can A842 Grade 450 be formed, bent or molded?
Green sand or shell molding with tight Mg/Ti and inoculation control (thermal analysis feedback); the compacted-graphite window is narrow so nodularity must be held below ~20 %.
What is the maximum service temperature of A842 Grade 450?
A842 Grade 450 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A842 Grade 450 AS-CAST and A842 Grade 450-N?
AS-CAST is the default condition — standard supply condition for Grade 450; alloying (Cu/Sn/Mn) gives a ~100 % pearlitic matrix straight from the mold. N: used when as-cast section size gives too much free ferrite; normalizing restores/raises pearlite content, strength and hardness at the cost of a little ductility and thermal conductivity. Yield strength is 350 MPa in AS-CAST versus 390 MPa in N.
How much does A842 Grade 450 cost?
A842 Grade 450 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 A842-11 Standard Specification for Compacted Graphite Iron Castings — ASTM International (2011)
- EN 16112 Founding — Compacted (vermicular) graphite cast irons — CEN (2011)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Compacted Graphite Iron material data — SinterCast AB (2023)
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.