Steel 1080 · supply condition · default condition
Steel 1080-HR
Properties of the HR condition, compared with the other 1080 tempers.
Cheapest stock form for blanks that will be machined and then hardened; pearlitic as-rolled structure.
What is 1080-HR?
1080-HR is 1080 supplied in the HR condition — cheapest stock form for blanks that will be machined and then hardened; pearlitic as-rolled structure. 1080-HR has a yield strength of 585 MPa (84.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 76% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi). 1080-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,385°C (2,525 °F).
Advantages
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
- High strength — 585 MPa (84.8 ksi), better than 76% of steel grades
Limitations
- Limited ductility — 12%, worse than 84% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
- Difficult to machine — 35/100, worse than 83% of steel grades
1080-HR properties
Typical room-temperature values for 1080-HR — 11 properties are specific to this condition; the rest are grade-level values shared by every 1080 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1080-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,385°C (2,525 °F).
Mechanical15
1080-HR has a yield strength of 585 MPa (84.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 76% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1080-HR 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
1080-HR conducts electricity at 9.5 % IACS, better than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of 1080-HR takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
1080-HR's machinability is fair (35/100, worse than 83% of steel grades); weldability poor (20/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1080 tempers and conditions
1080 is also supplied in 8 other conditions. The full side-by-side table is on the 1080 overview.
- HRDefaultCheapest stock form for blanks that will be machined and then hardened; pearlitic as-rolled structure.585 MPa yield · 31 HRC
- Q&T 50-55 HRCBlade, cutter and wear-part condition: maximum hardness and edge retention, low impact toughness.1,500 MPa yield · 52 HRC
- PatentedPatented (sorbitic) and heavily drawn wire for coil springs and wire forms — very high strength as-drawn, no further hardening needed.1,500 MPa yield · 47 HRC
- Q&TBalanced strength/toughness condition for springs, chisels and highly loaded machine parts in thin sections.980 MPa yield · 40 HRC
- CDUse when a bright, close-tolerance bar with higher yield strength is wanted straight from stock.855 MPa yield · 31 HRC
- CRThin strip for saw blades, shims, flat springs and stamped blades; tight thickness and good surface.830 MPa yield · 32 HRC
- SA+CDSpheroidize-annealed (globular carbides in ferrite) then cold drawn — moderate strength with the best cold formability and machinability attainable in 0.80 % C steel, the standard feed condition for cold-heading and pre-hardened spring parts.620 MPa yield · 20 HRC
- NormalizedUniform fine pearlite for consistent machining and predictable response to later hardening.524 MPa yield · 31 HRC
- AnnealedSoftest, most machinable and most formable condition — pick it for heavy machining or cold forming before hardening.375 MPa yield · 174 HB
Working with 1080-HR
Is 1080 easy to machine?
Machine in the annealed or normalized state with rigid setups, sharp carbide or coated carbide at moderate speed and good flood coolant; hardened 1080 needs grinding or ceramic/CBN tooling.
Can 1080 be welded?
Poor weldability — high carbon equivalent causes hard, crack-prone HAZ; if unavoidable use 200–300 °C preheat, low-hydrogen filler, slow cool and immediate stress relief/temper.
Can 1080 be formed, bent or molded?
Cold form only in the spheroidize-annealed condition and expect large springback; hot form at 950–1150 °C, then normalize before hardening.
What surface finishes work on 1080?
No corrosion resistance: finish with oil, black oxide, phosphate, zinc plating or paint; hardened surfaces take a fine polish and can be shot-peened for fatigue life.
1080 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 |
|---|---|---|
| CSAE J403/ASTM A29; GB 80 is 0.77–0.85 | 0.75 – 0.88 | 0.8 |
| MnGB 80 uses 0.17–0.37 Mn | 0.6 – 0.9 | 0.75 |
| Sitypical for killed hot-rolled product; not specified for all bar grades | 0.15 – 0.35 | 0.25 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.05 | 0.03 |
| Fe | balance | — |
1080-HR — frequently asked
What is 1080-HR used for?
1080-HR is typically used for flat and leaf springs, music and patented spring wire, mower and cutter blades, knife blanks, cold-work tool blanks and spiral and clock springs. In short: high-carbon spring bar.
What is the yield strength of 1080-HR?
1080-HR has a typical yield strength of 585 MPa (84.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 76% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 1080-HR easy to machine?
Not especially — machinability is rated fair (35/100, worse than 83% of steel grades). Machine in the annealed or normalized state with rigid setups, sharp carbide or coated carbide at moderate speed and good flood coolant; hardened 1080 needs grinding or ceramic/CBN tooling.
Can 1080-HR be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — high carbon equivalent causes hard, crack-prone HAZ; if unavoidable use 200–300 °C preheat, low-hydrogen filler, slow cool and immediate stress relief/temper.
What surface finishes work on 1080-HR?
No corrosion resistance: finish with oil, black oxide, phosphate, zinc plating or paint; hardened surfaces take a fine polish and can be shot-peened for fatigue life.
Can 1080-HR be formed, bent or molded?
Cold form only in the spheroidize-annealed condition and expect large springback; hot form at 950–1150 °C, then normalize before hardening.
What is the maximum service temperature of 1080-HR?
1080-HR 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 1080-HR and 1080-CD?
HR is the default condition — cheapest stock form for blanks that will be machined and then hardened; pearlitic as-rolled structure. CD: use when a bright, close-tolerance bar with higher yield strength is wanted straight from stock. Yield strength is 585 MPa in HR versus 855 MPa in CD.
Can FabDigit make parts in 1080-HR?
Yes — 1080-HR 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
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- GB/T 699 (grade 80) — SAC (2015)
- ASTM A684/A684M — High-Carbon Steel Strip — ASTM (2021)
- ASTM A227/A229 — Hard-Drawn and Oil-Tempered Spring Wire — ASTM (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating; Vol.16 — Machining — ASM International (1991)
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.