Steel 1340 · temper
Steel 1340 Annealed
Properties of the Annealed condition, compared with the other 1340 tempers.
Softest, most machinable and most formable condition; used for deep machining before hardening.
What is 1340 Annealed?
1340 Annealed is 1340 in the Annealed temper — softest, most machinable and most formable condition; used for deep machining before hardening. 1340 Annealed has a yield strength of 435 MPa (63.1 ksi) and a tensile strength of 705 MPa (102 ksi) — stronger than 50% of steel grades. Elongation at break is 25.5% and the elastic modulus is 205 GPa (29.7 Msi). 1340 Annealed 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). HR is the default condition FabDigit quotes; Annealed is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 25.5%, better than 80% of steel grades
1340 Annealed properties
Typical room-temperature values for 1340 Annealed — 12 properties are specific to this condition; the rest are grade-level values shared by every 1340 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1340 Annealed 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 Annealed has a yield strength of 435 MPa (63.1 ksi) and a tensile strength of 705 MPa (102 ksi) — stronger than 50% of steel grades. Elongation at break is 25.5% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1340 Annealed 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 Annealed conducts electricity at 7.8 % IACS, worse than 58% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of 1340 Annealed takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 55% of steel grades. Typical recycled content is 30%.
Manufacturability6
1340 Annealed's machinability is fair (52/100, better than 52% of steel grades); weldability fair (45/100); formability good (55/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1340 tempers and conditions
1340 is also supplied in 9 other conditions. The full side-by-side table is on the 1340 overview.
- HRDefaultCheapest stock condition for parts that will be machined and then heat treated.470 MPa yield · 217 HB
- Q&T 205CMaximum-hardness condition for wear parts; very low ductility and notch sensitivity, rarely used structurally.1,593 MPa yield · 50 HRC
- Q&T 315CHigh-strength wear/spring-like condition; watch tempered-martensite embrittlement in this range.1,462 MPa yield · 46 HRC
- Q&T 425CCommon high-strength shaft/bolt condition around 1200 MPa UTS with usable toughness.1,130 MPa yield · 40 HRC
- Q&TGeneral-purpose quenched-and-tempered condition balancing ~950 MPa strength with good toughness for shafts and bolts.830 MPa yield · 31 HRC
- CRPick for close tolerance, bright finish and higher as-supplied yield without heat treatment.705 MPa yield · 240 HB
- Q&T 650CToughest Q&T condition for impact-loaded or low-temperature parts where ~800 MPa is enough.621 MPa yield · 25 HRC
- Cold Finished1340 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 MPa yield · 207 HB
- NormalizedUniform fine-grain structure with higher strength than annealed; good pre-machining or as-delivered condition for forgings.558 MPa yield · 24 HRC
- AnnealedSoftest, most machinable and most formable condition; used for deep machining before hardening.435 MPa yield · 207 HB
Working with 1340 Annealed
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.
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.
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 | — |
1340 Annealed — frequently asked
What is 1340 Annealed used for?
1340 Annealed is typically used for shafts, forged gears and industrial bolts. In short: manganese chromium bar.
What is the yield strength of 1340 Annealed?
1340 Annealed has a typical yield strength of 435 MPa (63.1 ksi) and a tensile strength of 705 MPa (102 ksi) — stronger than 50% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 1340 Annealed easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% 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 Annealed be welded?
With care — weldability is rated fair (45/100). 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 Annealed?
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 Annealed 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 Annealed?
1340 Annealed 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.
Can FabDigit make parts in 1340 Annealed?
Yes — 1340 Annealed is available for CNC machining and sheet metal with instant online pricing. 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.