Steel 35L-AC (Spheroidize annealed)
Heat-treated state
GOST 35L
Untreated casting — only for non-critical parts; coarse dendritic structure with residual casting stresses.
Values for the AC condition
Other 35L tempers and conditions
35L is listed in 7 conditions; see the grade overview at 35L.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ACThis page Spheroidize annealed | Untreated casting — only for non-critical parts; coarse dendritic structure with residual casting stresses. | 265 | 490 | 12 | 155 HB | 9 % IACS |
Solution annealed | Full anneal near 860–880 °C with furnace cool for maximum machinability and lowest residual stress before finish machining. | 270 | 490 | 18 | 148 HB | 9 % IACS |
Stress relieved | 600–650 °C soak after casting, welding or rough machining to remove residual stress with minimal property change. | 280 | 505 | 16 | 158 HB | 9 % IACS |
N+TDefault Normalized and tempered | Standard delivery condition of GOST 977-88 castings — best balance of strength, ductility and stress relief for general machine parts. | 290 | 520 | 16 | 163 HB | — |
Normalized | Air-cooled from ~870 °C to refine the as-cast grain and raise strength; used when tempering is not specified. | 300 | 540 | 15 | 170 HB | 9 % IACS |
Quenched and tempered | Water/oil quench from ~860 °C plus 550–650 °C temper for the highest strength and best fatigue life in gears and couplings; section-size limited by hardenability. | 430 | 660 | 13 | 18 HRC | — |
Surface hardened | Induction- or flame-hardened teeth/journals on an N+T or Q&T core when wear resistance is needed; core properties unchanged. | 430 | 660 | 12 | 50 HRC | 8.5 % IACS |
What is 35L-AC?
35L-AC is 35L heat treated to AC — untreated casting — only for non-critical parts; coarse dendritic structure with residual casting stresses. 35L-AC has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 92% of steel grades. Elongation at break is 12% and the elastic modulus is 200 GPa (29 Msi). 35L-AC has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,425°C (2,597 °F). N+T is the default condition FabDigit quotes; AC is available on request or by drawing note.
Advantages
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
Limitations
- Limited formability — 10/100, worse than 95% of steel grades
- Low strength — 265 MPa (38.4 ksi), worse than 92% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
35L-AC properties
Typical room-temperature values for 35L-AC; 22 are specific to this condition. Other listed values are 35L reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
35L-AC has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
35L-AC has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 92% of steel grades. Elongation at break is 12% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
35L-AC is rated for continuous service to 380°C (716 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 12.1 µm/m·K (6.72 µin/in·°F).
Electrical3
35L-AC 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 35L-AC takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 80%.
Manufacturability8
35L-AC's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (40/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 35L-AC
Is 35L easy to machine?
Machine in the annealed or N+T condition with carbide tooling; expect abrasive sand/scale on the as-cast skin — take a heavy first cut.
Can 35L be welded?
Weldable with low-hydrogen E7018-type consumables, but CE ≈ 0.5 demands 150–250 °C preheat and a 600–650 °C post-weld stress relief to avoid HAZ cracking.
Can 35L be formed, bent or molded?
Sand or shell casting; feed heavy sections generously — steel's high shrinkage (~2 %) and narrow freezing range make risering and gating critical.
What surface finishes work on 35L?
Shot-blast and prime; protect with paint, zinc or phosphate coating since bare 35L rusts quickly. Induction hardening or nitrocarburizing can be used on wear surfaces.
35L 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 |
|---|---|---|
| CGOST 977-88 | 0.32 – 0.4 | 0.36 |
| Si | 0.2 – 0.52 | 0.35 |
| Mn | 0.4 – 0.9 | 0.65 |
| S≤0.06 for lower casting categories | ≤ 0.05 | 0.03 |
| P | ≤ 0.04 | 0.03 |
| Crresidual | ≤ 0.3 | 0.15 |
| Niresidual | ≤ 0.3 | 0.15 |
| Curesidual | ≤ 0.3 | 0.15 |
| Fe | balance | — |
35L-AC — frequently asked
What is 35L-AC used for?
35L-AC is typically used for gears, couplings, shafts (cast) and machine frames. In short: higher strength than 25L; heat-treatable GOST cast steel; preheat required for welding.
What is the yield strength of 35L-AC?
35L-AC has a typical yield strength of 265 MPa (38.4 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 92% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 35L-AC easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed or N+T condition with carbide tooling; expect abrasive sand/scale on the as-cast skin — take a heavy first cut.
Can 35L-AC be welded?
With care — weldability is rated fair (40/100). Weldable with low-hydrogen E7018-type consumables, but CE ≈ 0.5 demands 150–250 °C preheat and a 600–650 °C post-weld stress relief to avoid HAZ cracking.
What surface finishes work on 35L-AC?
Shot-blast and prime; protect with paint, zinc or phosphate coating since bare 35L rusts quickly. Induction hardening or nitrocarburizing can be used on wear surfaces.
Can 35L-AC be formed, bent or molded?
Sand or shell casting; feed heavy sections generously — steel's high shrinkage (~2 %) and narrow freezing range make risering and gating critical.
What is the maximum service temperature of 35L-AC?
35L-AC is rated for continuous use to about 380°C (716 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 35L N+T and 35L-SH?
N+T is the default condition — standard delivery condition of GOST 977-88 castings — best balance of strength, ductility and stress relief for general machine parts. SH: induction- or flame-hardened teeth/journals on an N+T or Q&T core when wear resistance is needed; core properties unchanged. Yield strength is 290 MPa in N+T versus 430 MPa in SH.
Sources
- ГОСТ 977-88 Отливки стальные. Общие технические условия — Gosstandart (1988)
- Marochnik stali i splavov — 35Л — Marochnik (2023)
- Steel Castings Handbook, 6th ed. — SFSA / ASM International (1995)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- GB/T 11352 (ZG270-500 comparison) — SAC (2009)
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.