Steel A148 105-85
Grade
ASTM A148
105-85 = grade 105-85 [725-585]
First clearly quench-and-tempered class; use for loaded gear blanks, links and housings needing ~585 MPa yield.
Values for the 105-85 condition
Other A148 tempers and conditions
A148 is listed in 12 conditions; see the grade overview at A148.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Grade 80-40 [550-275] | Lowest-strength A148 class; pick for large weldable structural castings where ductility and cost beat strength. | 320 | 585 | 24 | 150 HB | — |
Grade 80-50 [550-345] | Ductile general-purpose structural class with a higher yield floor than 80-40 at the same tensile level. | 385 | 585 | 24 | 160 HB | — |
90-60Default Grade 90-60 [620-415] | Most commonly ordered A148 class — good balance of strength, ductility and field weldability for general machinery castings. | 455 | 660 | 22 | 180 HB | — |
105-85This page Grade 105-85 [725-585] | First clearly quench-and-tempered class; use for loaded gear blanks, links and housings needing ~585 MPa yield. | 620 | 760 | 19 | 18 HRC | 43 W/m·K |
Grade 115-95 [795-655] | Mid-strength Q&T class for mining, rail and construction castings carrying high static loads. | 690 | 830 | 16 | 22 HRC | 42 W/m·K |
Grade 130-115 [895-795] | High-strength Q&T low-alloy casting for crane hooks, dipper teeth and heavy-duty gearing. | 830 | 930 | 13 | 27 HRC | 41 W/m·K |
Grade 135-125 [930-860] | High yield-to-tensile class where design is yield-limited and section sizes must stay small. | 895 | 965 | 11 | 29 HRC | 41 W/m·K |
Grade 150-135 [1035-930] | Very high strength Q&T casting for compact, heavily loaded parts; ductility and weldability are limited. | 965 | 1,070 | 9 | 33 HRC | 40 W/m·K |
Grade 160-145 [1105-1000] | Near-top strength class; specify only with tight NDT because notch sensitivity is high. | 1,035 | 1,140 | 8 | 35 HRC | 40 W/m·K |
Grade 165-150 [1140-1035] | Ultra-high-strength structural casting class for hooks, sockets and rigging hardware; requires low-S/P clean steel. | 1,070 | 1,180 | 7 | 37 HRC | 39 W/m·K |
Grade 210-180 [1450-1240] | Special ultra-high-strength class for armor-like and highly loaded compact castings; very low ductility, welding normally prohibited. | 1,310 | 1,500 | 5 | 44 HRC | 38 W/m·K |
Grade 260-210 [1795-1450] | Maximum-strength A148 class; essentially a martensitic casting used only where extreme strength justifies near-zero ductility. | 1,520 | 1,830 | 4 | 51 HRC | 37 W/m·K |
What is A148 105-85?
A148 105-85 is A148 in the 105-85 grade — first clearly quench-and-tempered class; use for loaded gear blanks, links and housings needing ~585 MPa yield. A148 105-85 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 78% of steel grades. Elongation at break is 19% and the elastic modulus is 205 GPa (29.7 Msi). A148 105-85 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). 90-60 is the default condition FabDigit quotes; 105-85 is available on request or by drawing note.
Advantages
- High strength — 620 MPa (89.9 ksi), better than 78% of steel grades
Limitations
- Limited formability — 10/100, worse than 95% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
A148 105-85 properties
Typical room-temperature values for A148 105-85; 17 are specific to this condition. Other listed values are A148 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A148 105-85 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).
Mechanical15
A148 105-85 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 78% of steel grades. Elongation at break is 19% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
A148 105-85 is rated for continuous service to 400°C (752 °F). It conducts heat at 43 W/m·K (24.8 BTU/hr·ft·°F), better than 51% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
A148 105-85 conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of A148 105-85 takes about 27 MJ of energy and emits 2 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 85%.
Manufacturability8
A148 105-85's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (50/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A148 105-85
Is A148 easy to machine?
Machine after heat treatment with rigid setups and carbide tooling; expect abrasive scale/sand at the as-cast skin — take a heavy first cut, and reduce speeds sharply above 300 HB.
Can A148 be welded?
Weldable in the lower classes (80-40 to 105-85) with low-hydrogen consumables, 150–260 °C preheat and post-weld stress relief; above ~130-115 obtain foundry approval and re-temper after welding.
Can A148 be formed, bent or molded?
Sand or shell cast with generous risering and chills — steel's ~2 % solidification shrinkage and low fluidity demand large gates, and all grades need normalizing or Q&T to break up the as-cast dendritic structure.
What surface finishes work on A148?
No anodizing; shot blast then phosphate plus paint, zinc-rich primer, hot-dip galvanizing or hard chrome on machined bearing surfaces; avoid electroplating of high-strength classes without hydrogen bake-out.
A148 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 |
|---|---|---|
| CNot fixed by A148 — chosen by the foundry; ≤0.30 % typical when weldability is required | 0.15 – 0.5 | 0.3 |
| Mnmanufacturer's option | 0.5 – 1.6 | 1 |
| Simanufacturer's option | 0.2 – 0.8 | 0.5 |
| PA148 maximum (0.04 max for higher-strength/weldable classes) | ≤ 0.05 | 0.02 |
| SA148 maximum (0.045 max for higher-strength/weldable classes) | ≤ 0.06 | 0.02 |
| Nioptional hardenability addition for 105-85 and stronger classes | 0 – 3.5 | 0.8 |
| Croptional | 0 – 1.5 | 0.6 |
| Mooptional; typical in Q&T classes | 0 – 0.6 | 0.25 |
| Voptional micro-alloy | 0 – 0.12 | 0.04 |
| Fe | balance | — |
A148 105-85 — frequently asked
What is A148 105-85 used for?
A148 105-85 is typically used for mining machinery frames, construction equipment parts, railway couplers, crane hooks and structural castings. In short: strength-class cast steel spec; widest cast strength range; chemistry left to foundry.
What is the yield strength of A148 105-85?
A148 105-85 has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 78% of steel grades. Strength varies by condition: see the 12 listed tempers.
Is A148 105-85 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine after heat treatment with rigid setups and carbide tooling; expect abrasive scale/sand at the as-cast skin — take a heavy first cut, and reduce speeds sharply above 300 HB.
Can A148 105-85 be welded?
With care — weldability is rated fair (50/100). Weldable in the lower classes (80-40 to 105-85) with low-hydrogen consumables, 150–260 °C preheat and post-weld stress relief; above ~130-115 obtain foundry approval and re-temper after welding.
What surface finishes work on A148 105-85?
No anodizing; shot blast then phosphate plus paint, zinc-rich primer, hot-dip galvanizing or hard chrome on machined bearing surfaces; avoid electroplating of high-strength classes without hydrogen bake-out.
Can A148 105-85 be formed, bent or molded?
Sand or shell cast with generous risering and chills — steel's ~2 % solidification shrinkage and low fluidity demand large gates, and all grades need normalizing or Q&T to break up the as-cast dendritic structure.
What is the maximum service temperature of A148 105-85?
A148 105-85 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 A148 90-60 and A148 260-210?
90-60 is the default condition — most commonly ordered A148 class — good balance of strength, ductility and field weldability for general machinery castings. 260-210: maximum-strength A148 class; essentially a martensitic casting used only where extreme strength justifies near-zero ductility. Yield strength is 455 MPa in 90-60 versus 1,520 MPa in 260-210.
Sources
- ASTM A148/A148M Standard Specification for Steel Castings, High Strength, for Structural Purposes — ASTM International (2020)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Cast Steels) — ASM International (1990)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
- ASTM A370 Standard Test Methods and Definitions for Mechanical Testing of Steel Products (hardness conversions) — ASTM International (2022)
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.