Steel 1340
AISI/SAE 1340 · UNS G13400
1340 (UNS G13400) is a medium-carbon, high-manganese alloy steel of the AISI/SAE 13xx series, in which manganese rather than chromium or nickel provides the hardenability.
Values for the HR condition
1340 tempers and conditions
1340 is supplied in 10 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full anneal ~800 °C, furnace cooled | Softest, most machinable and most formable condition; used for deep machining before hardening. | 435 | 705 | 25.5 | 207 HB | — |
HRDefault Hot rolled | Cheapest stock condition for parts that will be machined and then heat treated. | 470 | 745 | 20 | 217 HB | — |
870 °C, air cooled | Uniform fine-grain structure with higher strength than annealed; good pre-machining or as-delivered condition for forgings. | 558 | 836 | 22 | 24 HRC | — |
Cold Finished (Cold Drawn Bar) | 1340 manganese alloy steel supplied as cold-drawn/turned-and-polished bar: ~15–20 % strength gain and tight size tolerance over hot-rolled, with reduced ductility and residual stress. | 590 | 705 | 12 | 207 HB | 44 W/m·K |
oil quenched, high tempered (~25 HRC) | Toughest Q&T condition for impact-loaded or low-temperature parts where ~800 MPa is enough. | 621 | 800 | 22 | 25 HRC | — |
Cold rolled | Pick for close tolerance, bright finish and higher as-supplied yield without heat treatment. | 705 | 825 | 12 | 240 HB | — |
Quenched and tempered | General-purpose quenched-and-tempered condition balancing ~950 MPa strength with good toughness for shafts and bolts. | 830 | 951 | 17.8 | 31 HRC | — |
oil quenched, tempered 425 °C (~40 HRC) | Common high-strength shaft/bolt condition around 1200 MPa UTS with usable toughness. | 1,130 | 1,223 | 14.5 | 40 HRC | — |
oil quenched, tempered 315 °C (~46 HRC) | High-strength wear/spring-like condition; watch tempered-martensite embrittlement in this range. | 1,462 | 1,584 | 12.5 | 46 HRC | — |
oil quenched, low tempered (~50 HRC) | Maximum-hardness condition for wear parts; very low ductility and notch sensitivity, rarely used structurally. | 1,593 | 1,806 | 11 | 50 HRC | — |
What is 1340?
1340 (UNS G13400) is a medium-carbon, high-manganese alloy steel of the AISI/SAE 13xx series, in which manganese rather than chromium or nickel provides the hardenability. Quenched and tempered it reaches about 745 MPa tensile, 470 MPa yield, 20 % elongation and 217 HB, so it is used for shafts, forged gears and bolts needing more strength than plain carbon grades; bar is stocked hot-rolled, cold-finished, annealed, normalized and in several Q&T tempers. Carbon equivalent near 0.75 makes welding demanding, cold formability is limited and there is no corrosion resistance; 4140 is the more widely available alternative. 1340 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). 1340 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 745 MPa (108 ksi) — stronger than 57% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
What is 1340 used for?
- Shafts
- Forged gears
- Industrial bolts
1340 properties
Typical room-temperature values for 1340-HR; bars are the position among steel grades.
Physical3
1340 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).
Mechanical13
1340 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 745 MPa (108 ksi) — stronger than 57% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1340 is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
1340 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 1340 takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability6
1340's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (40/100); formability fair (40/100).
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. 1340 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1340
Is 1340 easy to machine?
Machine in the annealed or normalized condition (~55 % of 1212); use rigid setups, carbide at 120–180 m/min, and expect gummy chips from high Mn.
Can 1340 be welded?
Weldable with low-hydrogen consumables but CE ≈ 0.75 demands 200–300 °C preheat, interpass control and post-weld temper to avoid HAZ cracking.
Can 1340 be formed, bent or molded?
Hot forge 1100–1200 °C, finish above 900 °C; cold forming limited to mild bends in the annealed state due to high yield and work hardening.
Manufacturability
The process limits FabDigit applies to 1340. Every 1340 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better50 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair40 / 100 |
|---|---|
| Weldability | Better40 / 100 |
1340 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 |
|---|---|---|
| C | 0.38 – 0.43 | 0.4 |
| Mnprimary hardenability element | 1.6 – 1.9 | 1.75 |
| Si | 0.15 – 0.35 | 0.25 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 1340?
No inherent corrosion resistance — oil, black oxide, phosphate, zinc/Zn-Ni plating or paint; bake after plating to relieve hydrogen embrittlement above 40 HRC.
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 1340 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G13400
How much does 1340 cost?
1340 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
1340 — frequently asked
What is 1340 used for?
1340 is typically used for shafts, forged gears and industrial bolts. In short: manganese chromium bar.
What is the yield strength of 1340?
1340 has a typical yield strength of 470 MPa (68.2 ksi) and a tensile strength of 745 MPa (108 ksi) — stronger than 57% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 1340 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed or normalized condition (~55 % of 1212); use rigid setups, carbide at 120–180 m/min, and expect gummy chips from high Mn.
Can 1340 be welded?
With care — weldability is rated fair (40/100). Weldable with low-hydrogen consumables but CE ≈ 0.75 demands 200–300 °C preheat, interpass control and post-weld temper to avoid HAZ cracking.
What surface finishes work on 1340?
No inherent corrosion resistance — oil, black oxide, phosphate, zinc/Zn-Ni plating or paint; bake after plating to relieve hydrogen embrittlement above 40 HRC.
Can 1340 be formed, bent or molded?
Hot forge 1100–1200 °C, finish above 900 °C; cold forming limited to mild bends in the annealed state due to high yield and work hardening.
What is the maximum service temperature of 1340?
1340 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1340-HR and 1340-CR?
HR is the default condition — cheapest stock condition for parts that will be machined and then heat treated. CR: pick for close tolerance, bright finish and higher as-supplied yield without heat treatment. Yield strength is 470 MPa in HR versus 705 MPa in CR.
How much does 1340 cost?
1340 is a standard-cost steel ($$), 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.
Can FabDigit make parts in 1340?
Yes — 1340 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1397 — Estimated Mechanical Properties of Steel Bars — SAE International (2018)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating — ASM International (1991)
- GB/T 3077 (40Mn2) — SAC (2015)
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.