Steel GE320 +NT (Normalized and tempered)
Heat-treated state
EN 1.0591
Use when the normalized casting needs residual stresses removed and slightly better toughness at the same strength level.
Values for the +NT condition
Other GE320 tempers and conditions
GE320 is listed in 6 conditions; see the grade overview at GE320.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for maximum machinability and lowest hardness before final heat treatment of the finished casting. | 300 | 590 | 17 | 6 HRC | 9.8 % IACS |
Spheroidize annealed | Lowest-cost condition for non-critical, lightly loaded castings where property scatter and residual stress are acceptable. | 320 | 620 | 8 | 11 HRC | 9.5 % IACS |
Stress relieved | Choose when dimensional stability after heavy welding or machining matters more than a strength upgrade. | 330 | 630 | 10 | 11 HRC | 9.5 % IACS |
+NDefault Normalized | Standard supply condition that meets the EN 10293 GE320 minimums with a uniform fine pearlitic structure — default choice for general machine castings. | 360 | 660 | 13 | 13 HRC | 9.5 % IACS |
+NTThis page Normalized and tempered | Use when the normalized casting needs residual stresses removed and slightly better toughness at the same strength level. | 370 | 650 | 15 | 12 HRC | 9.5 % IACS |
Quenched and tempered | Specify for the highest strength and best strength/toughness balance in thick, heavily loaded sections; section size limits hardenability of an unalloyed grade. | 480 | 760 | 14 | 21 HRC | — |
What is GE320 +NT?
GE320 +NT is GE320 heat treated to +NT — use when the normalized casting needs residual stresses removed and slightly better toughness at the same strength level. GE320 +NT has a yield strength of 370 MPa (53.7 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 70% of steel grades. Elongation at break is 15% and the elastic modulus is 207 GPa (30 Msi). GE320 +NT has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F). +N is the default condition FabDigit quotes; +NT is available on request or by drawing note.
Advantages
- High electrical conductivity — 9.5 % IACS, better than 75% of steel grades
Limitations
- Limited formability — 17/100, worse than 84% of steel grades
GE320 +NT properties
Typical room-temperature values for GE320 +NT; 23 are specific to this condition. Other listed values are GE320 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
GE320 +NT has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical17
GE320 +NT has a yield strength of 370 MPa (53.7 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 70% of steel grades. Elongation at break is 15% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
GE320 +NT is rated for continuous service to 400°C (752 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), better than 75% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
GE320 +NT conducts electricity at 9.5 % IACS, better than 75% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of GE320 +NT takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 85%.
Manufacturability7
GE320 +NT's machinability is fair (52/100, better than 52% of steel grades); weldability fair (46/100); formability poor (17/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with GE320 +NT
Is GE320 easy to machine?
Machines like normalized 1035–1040 steel at roughly 55 % of 1212; use rigid setups and carbide inserts, and allow for hard skin/sand inclusions on unblasted surfaces.
Can GE320 be welded?
Weldable with low-hydrogen electrodes but the ~0.5 CEV demands 150–250 °C preheat, controlled interpass temperature and post-weld stress relief; not a first choice for heavily welded structures (use G20Mn5 instead).
Can GE320 be formed, bent or molded?
Sand or shell cast with generous 2 % shrinkage allowance, large risers and directional solidification; hot straightening only, no cold forming.
What surface finishes work on GE320?
Shot-blast then paint, zinc-rich primer, phosphate or hard chrome; can be flame- or induction-hardened locally, and takes a fair polish once porosity is avoided.
GE320 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 |
|---|---|---|
| CEN 10293 leaves C/Si/Mn to the producer; value shown is the typical foundry aim to reach ReH ≥ 320 MPa | 0.28 – 0.45 | 0.35 |
| Si | 0.2 – 0.6 | 0.45 |
| Mn | 0.5 – 1.2 | 0.9 |
| Pstandard limit | ≤ 0.03 | 0.02 |
| Sstandard limit | ≤ 0.03 | 0.02 |
| Crresidual | ≤ 0.3 | 0.1 |
| Niresidual | ≤ 0.4 | 0.15 |
| Moresidual | ≤ 0.15 | 0.04 |
| Curesidual | ≤ 0.3 | 0.15 |
| Fe | balance | — |
GE320 +NT — frequently asked
What is GE320 +NT used for?
GE320 +NT is typically used for heavy machine bases, crusher components and structural castings. In short: strongest of the GE series; heavy-load structural castings; limited weldability, higher CEV.
What is the yield strength of GE320 +NT?
GE320 +NT has a typical yield strength of 370 MPa (53.7 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 70% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is GE320 +NT easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines like normalized 1035–1040 steel at roughly 55 % of 1212; use rigid setups and carbide inserts, and allow for hard skin/sand inclusions on unblasted surfaces.
Can GE320 +NT be welded?
With care — weldability is rated fair (46/100). Weldable with low-hydrogen electrodes but the ~0.5 CEV demands 150–250 °C preheat, controlled interpass temperature and post-weld stress relief; not a first choice for heavily welded structures (use G20Mn5 instead).
What surface finishes work on GE320 +NT?
Shot-blast then paint, zinc-rich primer, phosphate or hard chrome; can be flame- or induction-hardened locally, and takes a fair polish once porosity is avoided.
Can GE320 +NT be formed, bent or molded?
Sand or shell cast with generous 2 % shrinkage allowance, large risers and directional solidification; hot straightening only, no cold forming.
What is the maximum service temperature of GE320 +NT?
GE320 +NT 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 GE320 +N and GE320-AC?
+N is the default condition — standard supply condition that meets the EN 10293 GE320 minimums with a uniform fine pearlitic structure — default choice for general machine castings. AC: lowest-cost condition for non-critical, lightly loaded castings where property scatter and residual stress are acceptable. Yield strength is 360 MPa in +N versus 320 MPa in AC.
Sources
- EN 10293 — Steel castings for general engineering uses — CEN (2015)
- DIN 1681 — Cast steels for general engineering purposes (GS-38…GS-60, superseded) — DIN (1985)
- GB/T 11352 — Carbon steel castings for general engineering purpose (ZG230-450…ZG340-640) — SAC (2009)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast carbon steels) — ASM International (1990)
- ASM Handbook Vol.15 — Casting — ASM International (2008)
- Machinery's Handbook (machinability ratings) — Industrial Press (2020)
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.