Steel 1084
AISI/SAE 1084 · UNS G10840
1084 is a plain high-carbon steel (about 0.85 % C, UNS G10840) with manganese as the only significant addition, sitting essentially at the eutectoid composition.
Values for the HR condition
1084 tempers and conditions
1084 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 |
|---|---|---|---|---|---|---|
Spheroidize annealed strip/bar | Choose for cold forming, deep drawing or heavy machining of high-carbon strip. | 350 | 600 | 28 | 174 HB | 10.4 % IACS |
full/subcritical anneal (coarse pearlite) | Softest condition for machining, drilling and blanking before hardening. | 380 | 640 | 24 | 187 HB | — |
Spheroidize Annealed + Cold Drawn | Globular-carbide spheroidized 1084 bar/wire finished by cold drawing — moderate strength with the best cold formability and machinability attainable in a eutectoid carbon steel. | 515 | 620 | 10 | 183 HB | 9.5 % IACS |
austenitized ~870–900 °C, air cooled | Use to refine forged grain structure and homogenize before hardening. | 525 | 1,010 | 11 | 31 HRC | 9.6 % IACS |
HRDefault Hot rolled | Cheapest stock form for forging, blade blanks and parts that will be re-heat-treated. | 585 | 965 | 12 | 31 HRC | — |
Cold rolled | Precision-thickness strip with good surface for saw blades, shims and spring clips. | 700 | 830 | 8 | 22 HRC | 9.5 % IACS |
Cold drawn | Tight tolerance, straight bar with raised yield strength for pins, punches and shafts. | 875 | 1,020 | 10 | 31 HRC | 9.5 % IACS |
Quenched and tempered | General-purpose hardened-and-tempered condition for springs, chisels and wear parts needing some toughness. | 1,000 | 1,290 | 10 | 41 HRC | — |
Quenched, tempered ~300–340 °C | Balance of hardness and shock resistance for cold chisels, punches, scrapers and heavy blades. | 1,280 | 1,650 | 6 | 50 HRC | — |
Quenched, low temper 175–205 °C | Standard knife/blade heat treat: maximum edge retention and hardness, minimal toughness margin. | 1,500 | 1,950 | 3 | 57 HRC | — |
What is 1084?
1084 is a plain high-carbon steel (about 0.85 % C, UNS G10840) with manganese as the only significant addition, sitting essentially at the eutectoid composition. It is used for knife blades, springs, scrapers, agricultural cutting edges and punches because it reaches 60+ HRC from an oil quench, has a wide heat-treatment window and forges and hand heat-treats easily; stock is available hot-rolled, cold-rolled, cold-drawn, annealed, normalized and Q&T to 48–52 or 55–58 HRC. Hardenability is shallow, so thick sections will not through-harden, corrosion resistance and weldability are poor, and as-quenched toughness is limited. 1095 is the nearest higher-carbon alternative. 1084 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). 1084 has a yield strength of 585 MPa (84.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 75% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
What is 1084 used for?
- Knives
- Hand tools
- Springs
Advantages
- Polishes to a fine finish — 75/100, better than 94% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
- High electrical conductivity — 9.6 % IACS, better than 78% of steel grades
- High strength — 585 MPa (84.8 ksi), better than 75% of steel grades
Limitations
- Limited ductility — 12%, worse than 84% of steel grades
- Difficult to machine — 35/100, worse than 84% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
1084 properties
Typical room-temperature values for 1084-HR; bars are the position among steel grades.
Physical3
1084 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
1084 has a yield strength of 585 MPa (84.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 75% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1084 is rated for continuous service to 400°C (752 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 11.3 µm/m·K (6.28 µin/in·°F).
Electrical3
1084 conducts electricity at 9.6 % IACS, better than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (8/100), worse than 99% of steel grades.
Sustainability4
Producing a kilogram of 1084 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
1084's machinability is fair (35/100, worse than 84% of steel grades); weldability poor (20/100); formability poor (30/100).
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. 1084 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1084
Is 1084 easy to machine?
Machine in the annealed or spheroidized state (≈45–55 % of 1212) with rigid setups and carbide or coated HSS; above 45 HRC switch to grinding, EDM or CBN.
Can 1084 be welded?
Poor weldability — 0.85 % C gives hard, crack-sensitive martensite; if unavoidable, preheat 250–300 °C, use low-hydrogen filler and post-weld temper immediately.
Can 1084 be formed, bent or molded?
Hot forge 1050–850 °C then normalize; cold bending only in spheroidized/annealed strip with generous radii, never in hardened condition.
Manufacturability
The process limits FabDigit applies to 1084. Every 1084 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair35 / 100 |
|---|---|
| ISO material group | P.1 |
| Cutting speed (rough / finish) | 220 / 260 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 | Fair30 / 100 |
|---|---|
| Weldability | Fair20 / 100 |
1084 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 |
|---|---|---|
| Ceutectoid carbon level | 0.8 – 0.93 | 0.86 |
| Mn | 0.6 – 0.9 | 0.75 |
| Sinot specified in SAE J403; typical mill practice for killed steel | 0.1 – 0.35 | 0.2 |
| P | ≤ 0.04 | |
| Smax (non-resulfurized grade) | ≤ 0.05 | |
| Fe | balance |
What surface finishes work on 1084?
Grinds and polishes to a fine finish but rusts quickly — protect with oil/wax, black oxide, phosphate, bluing, nickel or zinc plating; no anodizing.
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 1084 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G10840
- Similar grades
- 85
How much does 1084 cost?
1084 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
1084 — frequently asked
What is 1084 used for?
1084 is typically used for knives, hand tools and springs. In short: stronger spring steel.
What is the yield strength of 1084?
1084 has a typical yield strength of 585 MPa (84.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 75% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 1084 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Machine in the annealed or spheroidized state (≈45–55 % of 1212) with rigid setups and carbide or coated HSS; above 45 HRC switch to grinding, EDM or CBN.
Can 1084 be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — 0.85 % C gives hard, crack-sensitive martensite; if unavoidable, preheat 250–300 °C, use low-hydrogen filler and post-weld temper immediately.
What surface finishes work on 1084?
Grinds and polishes to a fine finish but rusts quickly — protect with oil/wax, black oxide, phosphate, bluing, nickel or zinc plating; no anodizing.
Can 1084 be formed, bent or molded?
Hot forge 1050–850 °C then normalize; cold bending only in spheroidized/annealed strip with generous radii, never in hardened condition.
What is the maximum service temperature of 1084?
1084 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1084-HR and 1084-CD?
HR is the default condition — cheapest stock form for forging, blade blanks and parts that will be re-heat-treated. CD: tight tolerance, straight bar with raised yield strength for pins, punches and shafts. Yield strength is 585 MPa in HR versus 875 MPa in CD.
How much does 1084 cost?
1084 is a standard-cost steel ($$), 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 1084?
Yes — 1084 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 J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASTM A682/A684 — High-Carbon Spring Steel Strip — ASTM (2019)
- ASM Handbook Vol.1: Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4: Heat Treating — ASM International (1991)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
- GB/T 1298 (T8/T9 comparison grades) — SAC (2008)
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.