Steel A372 Grade F
ASTM A372 Grade F
One of the lowest-strength classes of carbon/alloy steel forging defined in ASTM A372 for thin-walled pressure vessels; quenched-and-tempered forging used where moderate strength with good toughness is required.
Reference datasheet — A372 Grade F 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 CL70 condition
A372 Grade F tempers and conditions
A372 Grade F is supplied in 3 conditions, soft to hard. CL70 is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Class 55 | Lowest-strength class: choose when maximum ductility, reduction of area and toughness matter more than wall-thickness savings. | 415 | 640 | 23 | 190 HB | — |
Class 65 | Mid strength class: balanced compromise between wall thickness and toughness for accumulator and cylinder shells. | 485 | 690 | 21 | 16 HRC | — |
CL70Default Class 70 | Highest class of Grade F: choose for the thinnest practical vessel wall while retaining ductile behaviour. | 520 | 720 | 20 | 18 HRC | — |
What is A372 Grade F?
One of the lowest-strength classes of carbon/alloy steel forging defined in ASTM A372 for thin-walled pressure vessels; quenched-and-tempered forging used where moderate strength with good toughness is required. A372 Grade F 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). A372 Grade F has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 67% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
What is A372 Grade F used for?
- gas cylinder forgings
- pressure vessel shells
- gun tube blanks
- high-pressure component forgings
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
A372 Grade F properties
Typical room-temperature values for A372 Grade F-CL70; bars are the position among steel grades.
Physical3
A372 Grade F 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).
Mechanical17
A372 Grade F has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 67% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
A372 Grade F is rated for continuous service to 400°C (752 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
A372 Grade F conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of A372 Grade F takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
A372 Grade F's machinability is good (55/100, better than 62% of steel grades); weldability good (55/100); formability fair (35/100).
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. A372 Grade F is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A372 Grade F
Is A372 Grade F easy to machine?
Machines like Q&T medium-carbon steel at 190–235 HB; use rigid setups, coated carbide, ~100–160 m/min, and rough before final tempering where tolerances are tight.
Can A372 Grade F be welded?
Weldable with low-hydrogen consumables but CE ≈ 0.5: preheat 150–250 °C, control interpass, and PWHT/re-heat-treat to restore Q&T properties in pressure-retaining welds.
Can A372 Grade F be formed, bent or molded?
Hot forged/pierced or flow-formed into the vessel shell, then austenitised, quenched and tempered; cold forming in the Q&T state is limited to minor straightening.
A372 Grade F 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 |
|---|---|---|
| Cheat analysis, ASTM A372/A372M Grade F; verify against current edition | ≤ 0.35 | 0.3 |
| MnC-Mn hardenability base | 0.6 – 1.35 | 1 |
| Sideoxidation; fully killed, fine grain | 0.15 – 0.35 | 0.25 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Febalance; residual Cr/Ni/Mo/Cu limited by purchaser agreement | balance |
What surface finishes work on A372 Grade F?
No corrosion resistance of its own — shot-blast then paint, zinc-rich primer, phosphate or internal coating; avoid electroplating processes that risk hydrogen embrittlement without bake-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 A372 Grade F in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- A372-F
How much does A372 Grade F cost?
A372 Grade F 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.
A372 Grade F — frequently asked
What is A372 Grade F used for?
A372 Grade F is typically used for gas cylinder forgings, pressure vessel shells, gun tube blanks and high-pressure component forgings. In short: thin-wall pressure vessel forging; Q&T strength with toughness; lower-strength A372 class.
What is the yield strength of A372 Grade F?
A372 Grade F has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 67% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A372 Grade F easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines like Q&T medium-carbon steel at 190–235 HB; use rigid setups, coated carbide, ~100–160 m/min, and rough before final tempering where tolerances are tight.
Can A372 Grade F be welded?
Yes — weldability is rated good (55/100). Weldable with low-hydrogen consumables but CE ≈ 0.5: preheat 150–250 °C, control interpass, and PWHT/re-heat-treat to restore Q&T properties in pressure-retaining welds.
What surface finishes work on A372 Grade F?
No corrosion resistance of its own — shot-blast then paint, zinc-rich primer, phosphate or internal coating; avoid electroplating processes that risk hydrogen embrittlement without bake-out.
Can A372 Grade F be formed, bent or molded?
Hot forged/pierced or flow-formed into the vessel shell, then austenitised, quenched and tempered; cold forming in the Q&T state is limited to minor straightening.
What is the maximum service temperature of A372 Grade F?
A372 Grade F 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 A372 Grade F-CL70 and A372 Grade F-CL55?
CL70 is the default condition — highest class of Grade F: choose for the thinnest practical vessel wall while retaining ductile behaviour. CL55: lowest-strength class: choose when maximum ductility, reduction of area and toughness matter more than wall-thickness savings. Yield strength is 520 MPa in CL70 versus 415 MPa in CL55.
How much does A372 Grade F cost?
A372 Grade F 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 A372/A372M — Carbon and Alloy Steel Forgings for Thin-Walled Pressure Vessels — ASTM International (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- ASTM A370 — Mechanical Testing of Steel Products (hardness conversions) — ASTM International (2022)
- NACE MR0175/ISO 15156 — Materials for H2S-containing environments — NACE/ISO (2015)
- Mysteel / 1688 — Mysteel (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.