Steel 1070
AISI/SAE 1070 · UNS G10700 · EN 1.1520 · GB 70
1070 (G10700 / C70 / 1.1520 / GB 70) is an unalloyed high-carbon structural and spring steel at about 0.70 % C that develops high strength, hardness and elastic limit either from a fine pearlitic structure or from quenching and tempering (50–55 HRC on file).
Values for the HR condition
1070 tempers and conditions
1070 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/spheroidize annealed for machining and forming | Pick when the part must be machined, blanked or cold formed before hardening. | 350 | 630 | 22 | 183 HB | — |
HRDefault Hot rolled | Cheapest stock form for parts that will be re-heat-treated or machined then hardened. | 385 | 690 | 13 | 201 HB | — |
austenitized ~870 °C, air cooled (fine pearlite) | Uniform fine pearlite with higher strength than as-rolled; good pre-treatment before machining or hardening. | 500 | 900 | 12 | 26 HRC | — |
Spheroidized Annealed & Cold Drawn | Spheroidize-annealed to globular carbides for maximum cold workability, then cold drawn — moderate strength with good ductility and improved machinability for cold heading, upsetting and further wire/bar processing. | 620 | 730 | 11 | 210 HB | 48 W/m·K |
Cold rolled | Cold rolled high-carbon strip for stampings, shims, saw and blade blanks that are hardened afterwards. | 650 | 780 | 8 | 19 HRC | 9 % IACS |
Cold drawn | Close tolerance, higher-yield bar or wire for springs, pins and machined parts without further heat treatment. | 720 | 830 | 9 | 24 HRC | — |
Quenched and tempered | Highest strength/elastic limit condition for springs, blades and wear parts; accept low ductility and no welding. | 1,250 | 1,400 | 8 | 43 HRC | — |
Blue/hardened-and-tempered spring strip | Pre-hardened thin strip for clips, retaining rings and flat springs formed directly to shape. | 1,350 | 1,550 | 5 | 47 HRC | 8 % IACS |
Oil tempered spring wire | Ready-to-coil spring wire supplied at final strength — no post-coiling hardening needed, only stress relief. | 1,400 | 1,600 | 7 | 46 HRC | 8 % IACS |
quenched and low-temperature tempered (250–350 °C) | Use for cutting edges, scraper blades and wear plates where hardness matters more than toughness. | 1,600 | 1,850 | 4 | 52 HRC | — |
What is 1070?
1070 (G10700 / C70 / 1.1520 / GB 70) is an unalloyed high-carbon structural and spring steel at about 0.70 % C that develops high strength, hardness and elastic limit either from a fine pearlitic structure or from quenching and tempering (50–55 HRC on file). It is used for leaf and coil springs, washers, blades and agricultural wear parts, and is stocked as cold-rolled spring strip as well as hot-rolled and cold-drawn bar. Weldability is poor (hard, crack-prone HAZ), toughness and cold formability are limited, and it has no corrosion resistance, so oiling or coating is needed; 1050 is the more formable and weld-tolerant alternative. 1070 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). 1070 has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 65% of steel grades. Elongation at break is 13% and the elastic modulus is 205 GPa (29.7 Msi).
What is 1070 used for?
- Saw blades
- Cutting knives
- Springs
Advantages
- Conducts heat well — 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 90% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
- Limited ductility — 13%, worse than 78% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
1070 properties
Typical room-temperature values for 1070-HR; bars are the position among steel grades.
Physical3
1070 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).
Mechanical15
1070 has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 65% of steel grades. Elongation at break is 13% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1070 is rated for continuous service to 300°C (572 °F). It conducts heat at 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
1070 conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (9/100), worse than 98% of steel grades.
Sustainability4
Producing a kilogram of 1070 takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability6
1070's machinability is fair (45/100, worse than 65% 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. 1070 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1070
Is 1070 easy to machine?
Machine in the annealed or spheroidized state with rigid setups, carbide tooling and moderate speeds; above ~35 HRC use CBN/ceramic or switch to grinding.
Can 1070 be welded?
Poor weldability — high carbon equivalent causes hard, crack-prone HAZ; if unavoidable use 200–350 °C preheat, low-hydrogen consumables and immediate post-weld temper.
Can 1070 be formed, bent or molded?
Cold form only in annealed/soft strip condition with generous bend radii; hot forge 1150–850 °C then slow cool or normalize to avoid quench cracks.
Manufacturability
The process limits FabDigit applies to 1070. Every 1070 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair45 / 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 | Poor20 / 100 |
| Bendable | Yes |
| Minimum bend radius | 0.5× thickness |
| Spring-back | Low |
| Welding processes | MIG, TIG, SPOT, LASER |
1070 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 70 steel: 0.67–0.75 | 0.65 – 0.75 | 0.7 |
| MnGB/T 699 grade 70: 0.50-0.80 | 0.6 – 0.9 | 0.75 |
| Sinot specified in AISI/SAE bar chemistry; GB 70: 0.17–0.37 | 0.15 – 0.35 | 0.25 |
| Pmax, GB 70: ≤0.035 | ≤ 0.04 | 0.02 |
| Smax, GB 70: ≤0.035 | ≤ 0.05 | 0.03 |
| Crresidual (GB limit) | ≤ 0.25 | |
| Niresidual (GB limit) | ≤ 0.3 | |
| Curesidual (GB limit) | ≤ 0.25 | |
| Fe | balance |
What surface finishes work on 1070?
No inherent corrosion protection: use oil, phosphate, black oxide, zinc or paint; after acid pickling or electroplating of hardened parts bake at 190–210 °C to relieve hydrogen embrittlement. Fine pearlitic or tempered structures take a high mirror polish.
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 1070 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G10700
- EN / DIN / Werkstoff-Nr.
- 1.1520
- GB (China)
- 70
- Similar grades
- C70
How much does 1070 cost?
1070 is a standard-cost steel ($$), cheaper than about 80% 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.
1070 — frequently asked
What is 1070 used for?
1070 is typically used for saw blades, cutting knives and springs. In short: spring carbon steel.
What is the yield strength of 1070?
1070 has a typical yield strength of 385 MPa (55.8 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 65% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 1070 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed or spheroidized state with rigid setups, carbide tooling and moderate speeds; above ~35 HRC use CBN/ceramic or switch to grinding.
Can 1070 be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — high carbon equivalent causes hard, crack-prone HAZ; if unavoidable use 200–350 °C preheat, low-hydrogen consumables and immediate post-weld temper.
What surface finishes work on 1070?
No inherent corrosion protection: use oil, phosphate, black oxide, zinc or paint; after acid pickling or electroplating of hardened parts bake at 190–210 °C to relieve hydrogen embrittlement. Fine pearlitic or tempered structures take a high mirror polish.
Can 1070 be formed, bent or molded?
Cold form only in annealed/soft strip condition with generous bend radii; hot forge 1150–850 °C then slow cool or normalize to avoid quench cracks.
What is the maximum service temperature of 1070?
1070 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1070-HR and 1070-OT?
HR is the default condition — cheapest stock form for parts that will be re-heat-treated or machined then hardened. OT: ready-to-coil spring wire supplied at final strength — no post-coiling hardening needed, only stress relief. Yield strength is 385 MPa in HR versus 1,400 MPa in OT.
How much does 1070 cost?
1070 is a standard-cost steel ($$), cheaper than about 80% 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 1070?
Yes — 1070 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 / ASTM A29 — Carbon steel bars, grade 1070 — SAE / ASTM (2019)
- ASTM A684 — High-carbon cold-rolled strip — ASTM (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating — ASM International (1991)
- Machining Data Handbook — Metcut Research Associates (1980)
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.