Steel A27 Grade 70-36
ASTM A27 Grade 70-36
A27 Grade 70-36 is a structural cast carbon steel covered by ASTM A27, the grade name giving the minimum 70 ksi tensile / 36 ksi yield combination (about 515 MPa tensile, 290 MPa yield, 26 % elongation, 150 HB).
Reference datasheet — A27 Grade 70-36 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 GR70-36 condition
A27 Grade 70-36 tempers and conditions
A27 Grade 70-36 is supplied in 7 conditions, soft to hard. GR70-36 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Grade 60-30 | Lowest-strength, most ductile and most weldable A27 tensile grade — for lightly loaded or weld-fabricated structural castings. | 240 | 450 | 30 | 131 HB | — |
Grade U-60-30 | Cheapest option: as-cast (no heat treatment) with the same tensile minima as 60-30 but lower and less uniform toughness — use only for non-critical, room-temperature service. | 240 | 455 | 25 | 135 HB | — |
Grade N-1 | Ordered when only composition and weldability matter (e.g. weld-fabricated assemblies, non-structural castings); properties not guaranteed. | 240 | 450 | 22 | 135 HB | 10 % IACS |
Grade N-2 | Heat-treated version of N-1: better toughness and uniformity where mechanical acceptance testing is not required. | 255 | 470 | 28 | 140 HB | 10 % IACS |
Grade 65-35 | Mid-strength general structural casting grade with slightly better ductility than 70-36. | 275 | 485 | 28 | 140 HB | 10.5 % IACS |
GR70-36Default Grade 70-36 | Highest-strength A27 grade with 36 ksi yield and good ductility — default choice for railroad, mining and heavy machinery structural castings. | 290 | 515 | 26 | 150 HB | 10 % IACS |
Grade 70-40 | Pick when 40 ksi minimum yield is needed together with weldability — lower carbon, higher manganese than 70-36. | 315 | 520 | 26 | 155 HB | — |
What is A27 Grade 70-36?
A27 Grade 70-36 is a structural cast carbon steel covered by ASTM A27, the grade name giving the minimum 70 ksi tensile / 36 ksi yield combination (about 515 MPa tensile, 290 MPa yield, 26 % elongation, 150 HB). Engineers use it for mechanical and structural sand castings such as railroad, mining and machinery components where good weldability, weld repairability and moderate strength matter more than pressure certification. The specification covers non-pressure castings and offers no corrosion resistance, with a practical service ceiling near 425 °C; for pressure-retaining bodies specify A216 WCB instead. A27 Grade 70-36 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). A27 Grade 70-36 has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 515 MPa (74.7 ksi) — weaker than 88% of steel grades. Elongation at break is 26% and the elastic modulus is 200 GPa (29 Msi).
What is A27 Grade 70-36 used for?
- Railroad couplers
- Mining equipment castings
- Gears
- Machine frames
- Structural castings
Advantages
- Conducts heat well — 50 W/m·K (28.9 BTU/hr·ft·°F), better than 87% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
- Readily welded — 78/100, better than 78% of steel grades
Limitations
- Low strength — 290 MPa (42.1 ksi), worse than 88% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
- Limited formability — 20/100, worse than 80% of steel grades
A27 Grade 70-36 properties
Typical room-temperature values for A27 Grade 70-36-GR70-36; bars are the position among steel grades.
Physical3
A27 Grade 70-36 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
A27 Grade 70-36 has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 515 MPa (74.7 ksi) — weaker than 88% of steel grades. Elongation at break is 26% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A27 Grade 70-36 is rated for continuous service to 425°C (797 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), better than 87% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
A27 Grade 70-36 conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of A27 Grade 70-36 takes about 26 MJ of energy and emits 2.1 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 85%.
Manufacturability8
A27 Grade 70-36's machinability is good (55/100, better than 62% of steel grades); weldability very good (78/100); formability poor (20/100).
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. A27 Grade 70-36 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A27 Grade 70-36
Is A27 Grade 70-36 easy to machine?
Machines like normalized 1030 steel (≈60 % of AISI 1212); use rigid setups, carbide tooling and allow for hard scale/sand inclusions on unclean cast surfaces.
Can A27 Grade 70-36 be welded?
Readily welded and weld-repaired with E7018/ER70S-6; preheat 100–150 °C for sections over ~25 mm and stress relieve or re-normalize critical castings after major repair.
Can A27 Grade 70-36 be formed, bent or molded?
Green-sand or no-bake molding with generous risers and chills; steel's low fluidity and ~2 % solidification shrinkage require good gating and 1.5–2.5 % pattern shrink allowance.
A27 Grade 70-36 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 |
|---|---|---|
| CGrade 70-36 max 0.35 %; 70-40 and U-60-30 max 0.25 %; 60-30/65-35 max 0.30 % (per A27 Table 1) | ≤ 0.35 | 0.3 |
| MnGrade 70-40 allows up to ~1.20 % Mn; 60-30 max 0.60 % | ≤ 0.7 | 0.6 |
| Si | ≤ 0.8 | 0.5 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.05 | 0.03 |
| Curesidual element | ≤ 0.5 | 0.15 |
| Niresidual element | ≤ 0.5 | 0.15 |
| Crresidual element | ≤ 0.4 | 0.15 |
| Moresidual element | ≤ 0.25 | 0.05 |
| Vresidual element; total residuals typically limited to 1.00 % | ≤ 0.03 | 0.01 |
| Fe | balance |
What surface finishes work on A27 Grade 70-36?
Shot blast to remove scale, then prime/paint, phosphate, zinc plate or hot-dip galvanize; not anodizable, and case hardening (carburize/flame) is possible on the higher-carbon grades.
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 A27 Grade 70-36 cost?
A27 Grade 70-36 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.
A27 Grade 70-36 — frequently asked
What is A27 Grade 70-36 used for?
A27 Grade 70-36 is typically used for railroad couplers, mining equipment castings, gears, machine frames and structural castings. In short: general structural cast steel; multiple strength grades available; easily weld-repaired.
What is the yield strength of A27 Grade 70-36?
A27 Grade 70-36 has a typical yield strength of 290 MPa (42.1 ksi) and a tensile strength of 515 MPa (74.7 ksi) — weaker than 88% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is A27 Grade 70-36 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines like normalized 1030 steel (≈60 % of AISI 1212); use rigid setups, carbide tooling and allow for hard scale/sand inclusions on unclean cast surfaces.
Can A27 Grade 70-36 be welded?
Yes — weldability is rated very good (78/100). Readily welded and weld-repaired with E7018/ER70S-6; preheat 100–150 °C for sections over ~25 mm and stress relieve or re-normalize critical castings after major repair.
What surface finishes work on A27 Grade 70-36?
Shot blast to remove scale, then prime/paint, phosphate, zinc plate or hot-dip galvanize; not anodizable, and case hardening (carburize/flame) is possible on the higher-carbon grades.
Can A27 Grade 70-36 be formed, bent or molded?
Green-sand or no-bake molding with generous risers and chills; steel's low fluidity and ~2 % solidification shrinkage require good gating and 1.5–2.5 % pattern shrink allowance.
What is the maximum service temperature of A27 Grade 70-36?
A27 Grade 70-36 is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A27 Grade 70-36 GR70-36 and A27 Grade 70-36 GR60-30?
GR70-36 is the default condition — highest-strength A27 grade with 36 ksi yield and good ductility — default choice for railroad, mining and heavy machinery structural castings. GR60-30: lowest-strength, most ductile and most weldable A27 tensile grade — for lightly loaded or weld-fabricated structural castings. Yield strength is 290 MPa in GR70-36 versus 240 MPa in GR60-30.
How much does A27 Grade 70-36 cost?
A27 Grade 70-36 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 A27/A27M — Standard Specification for Steel Castings, Carbon, for General Application — ASTM International (2020)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM International (1995)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- GB/T 11352 (ZG200-400…ZG310-570) — SAC (China) (2009)
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.