Steel ZG340-640
GB GB/T 11352
ZG340-640 is the highest common strength tier of the GB/T 11352 general cast carbon steel series, a roughly 0.5 % C pearlitic cast steel specified at 340 MPa minimum yield and 640 MPa minimum tensile, typically supplied at 360 MPa yield, 660 MPa tensile, 11 % elongation and about 210 HB.
Reference datasheet — ZG340-640 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 Normalized condition
ZG340-640 tempers and conditions
ZG340-640 is supplied in 6 conditions, soft to hard. Normalized is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full anneal (~840–870 °C, furnace cool) | Pick when maximum machinability and stress relief matter more than strength, e.g. before heavy rough machining. | 320 | 600 | 14 | 180 HB | — |
As fabricated | Lowest-cost condition for non-critical wear parts where cast-in stresses and coarse structure are acceptable. | 330 | 630 | 8 | 14 HRC | 8.6 % IACS |
NormalizedDefault 850–880 °C, air cool (standard GB/T 11352 delivery) | Default stocked condition: meets the 340/640 MPa spec with uniform fine pearlitic structure and good wear resistance. | 360 | 660 | 11 | 210 HB | — |
Normalized and tempered | Use when residual stresses from normalizing must be relieved while keeping spec strength and slightly better toughness. | 370 | 670 | 13 | 17 HRC | 8.6 % IACS |
Quenched and tempered | Highest strength/toughness combination for heavily loaded gears and rolls; section size limited by hardenability and quench-crack risk at 0.55%C. | 550 | 800 | 12 | 26 HRC | — |
Quenched and low-tempered for wear | Choose for abrasion-dominated castings (crusher parts, wear plates) where hardness outranks impact toughness. | 750 | 1,000 | 6 | 34 HRC | — |
What is ZG340-640?
ZG340-640 is the highest common strength tier of the GB/T 11352 general cast carbon steel series, a roughly 0.5 % C pearlitic cast steel specified at 340 MPa minimum yield and 640 MPa minimum tensile, typically supplied at 360 MPa yield, 660 MPa tensile, 11 % elongation and about 210 HB. It is chosen for heavily stressed, wear-resistant sand castings that must carry contact and impact loads, and is available in F, annealed, normalized, N+T and Q&T conditions. The trade-offs are a carbon equivalent of about 0.6–0.75 that makes welding difficult, only 11 % elongation, no inherent corrosion resistance and a service ceiling near 400 °C. Where weld repair matters more than strength, step down one tier in the same GB/T 11352 series. ZG340-640 has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,425°C (2,597 °F). ZG340-640 has a yield strength of 360 MPa (52.2 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 72% of steel grades. Elongation at break is 11% and the elastic modulus is 205 GPa (29.7 Msi).
What is ZG340-640 used for?
- crusher hammers
- large gears
- heavy-duty machine bases
- mining equipment parts
Limitations
- Limited ductility — 11%, worse than 89% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
ZG340-640 properties
Typical room-temperature values for ZG340-640-Normalized; bars are the position among steel grades.
Physical3
ZG340-640 has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
ZG340-640 has a yield strength of 360 MPa (52.2 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 72% of steel grades. Elongation at break is 11% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
ZG340-640 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 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
ZG340-640 conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of ZG340-640 takes about 24 MJ of energy and emits 2 kg of CO₂ — less than 97% of steel grades. Typical recycled content is 80%.
Manufacturability8
ZG340-640's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (35/100); formability poor (15/100).
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. ZG340-640 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZG340-640
Is ZG340-640 easy to machine?
As a 0.5 % C pearlitic cast steel it cuts normally in the normalized condition with coated carbide at vc ≈ 100–150 m/min. Hard spots and residual sand in the as-cast skin chip cutting edges, so remove the skin layer first; in the Q&T condition reduce speed and increase feed.
Can ZG340-640 be welded?
Carbon equivalent is high (about 0.6–0.75), so weldability is poor: preheat to 150–250 °C, use low-hydrogen electrodes (E7015/E7016 or E5015), control interpass temperature and stress relieve at 600–650 °C after welding, otherwise cold cracking is likely.
Can ZG340-640 be formed, bent or molded?
Mainly sand cast at a pouring temperature of about 1540–1580 °C with roughly 2 % linear shrinkage; provide enough risers and chills to avoid shrinkage cavities. Abrupt thick-to-thin transitions hot tear, so keep wall thickness uniform and use generous fillet radii.
ZG340-640 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 |
|---|---|---|
| CGB/T 11352 caps C ≤0.60; held near 0.5 % for strength | 0.45 – 0.6 | 0.55 |
| Si | 0.2 – 0.6 | 0.45 |
| Mn | 0.5 – 0.9 | 0.8 |
| Pmaximum, general use | ≤ 0.04 | 0.02 |
| Smaximum, general use | ≤ 0.04 | 0.02 |
| Niresidual element | ≤ 0.3 | |
| Crresidual element | ≤ 0.35 | |
| Curesidual element | ≤ 0.3 | |
| Moresidual element | ≤ 0.2 | |
| Vresidual element; total residuals ≤1.00 % | ≤ 0.05 | |
| Fe | balance |
What surface finishes work on ZG340-640?
Not anodizable; after shot blasting apply phosphate plus primer or epoxy paint, zinc plating or black oxide for rust protection. Sliding wear faces can be flame or induction hardened, or nitrided, to raise surface hardness.
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 ZG340-640 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- GB (China)
- GB/T 11352
- Also called
- ZG55
How much does ZG340-640 cost?
ZG340-640 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.
ZG340-640 — frequently asked
What is ZG340-640 used for?
ZG340-640 is typically used for crusher hammers, large gears, heavy-duty machine bases and mining equipment parts. In short: strongest common GB/T 11352 tier; wear-resistant cast steel; poor weldability, high CE.
What is the yield strength of ZG340-640?
ZG340-640 has a typical yield strength of 360 MPa (52.2 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 72% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is ZG340-640 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). As a 0.5 % C pearlitic cast steel it cuts normally in the normalized condition with coated carbide at vc ≈ 100–150 m/min. Hard spots and residual sand in the as-cast skin chip cutting edges, so remove the skin layer first; in the Q&T condition reduce speed and increase feed.
Can ZG340-640 be welded?
With care — weldability is rated fair (35/100). Carbon equivalent is high (about 0.6–0.75), so weldability is poor: preheat to 150–250 °C, use low-hydrogen electrodes (E7015/E7016 or E5015), control interpass temperature and stress relieve at 600–650 °C after welding, otherwise cold cracking is likely.
What surface finishes work on ZG340-640?
Not anodizable; after shot blasting apply phosphate plus primer or epoxy paint, zinc plating or black oxide for rust protection. Sliding wear faces can be flame or induction hardened, or nitrided, to raise surface hardness.
Can ZG340-640 be formed, bent or molded?
Mainly sand cast at a pouring temperature of about 1540–1580 °C with roughly 2 % linear shrinkage; provide enough risers and chills to avoid shrinkage cavities. Abrupt thick-to-thin transitions hot tear, so keep wall thickness uniform and use generous fillet radii.
What is the maximum service temperature of ZG340-640?
ZG340-640 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 ZG340-640 Normalized and ZG340-640-F?
Normalized is the default condition — default stocked condition: meets the 340/640 MPa spec with uniform fine pearlitic structure and good wear resistance. F: lowest-cost condition for non-critical wear parts where cast-in stresses and coarse structure are acceptable. Yield strength is 360 MPa in Normalized versus 330 MPa in F.
How much does ZG340-640 cost?
ZG340-640 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
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Cast Steels) — ASM International (1990)
- ASM Handbook Vol. 15 — Casting — ASM International (2008)
- ASTM A27/A148 (comparable cast carbon steel grades) — ASTM International (2020)
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.