Steel 1065 · hardness band
Steel 1065 H&T-Spring
Properties of the H&T-Spring condition, compared with the other 1065 tempers.
Pre-hardened strip supplied ready to form flat springs, clips, shims and doctor blades — no further heat treatment.
What is 1065 H&T-Spring?
1065 H&T-Spring is 1065 heat treated to H&T-Spring — pre-hardened strip supplied ready to form flat springs, clips, shims and doctor blades — no further heat treatment. 1065 H&T-Spring has a yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 96% of steel grades. Elongation at break is 5% and the elastic modulus is 205 GPa (29.7 Msi). 1065 H&T-Spring 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; H&T-Spring is available on request or by drawing note.
Advantages
- High strength — 1,400 MPa (203 ksi), better than 96% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- 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
- Difficult to weld — 10/100, worse than 99% of steel grades
- Limited ductility — 5%, worse than 98% of steel grades
- Difficult to machine — 20/100, worse than 97% of steel grades
- Limited formability — 12/100, worse than 91% of steel grades
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 90% of steel grades
1065 H&T-Spring properties
Typical room-temperature values for 1065 H&T-Spring — 12 properties are specific to this condition; the rest are grade-level values shared by every 1065 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1065 H&T-Spring 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
1065 H&T-Spring has a yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 96% of steel grades. Elongation at break is 5% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1065 H&T-Spring is rated for continuous service to 250°C (482 °F). It conducts heat at 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades. Thermal expansion is 11.3 µm/m·K (6.28 µin/in·°F).
Electrical3
1065 H&T-Spring 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 1065 H&T-Spring takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
1065 H&T-Spring's machinability is poor (20/100, worse than 97% of steel grades); weldability not recommended (10/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1065 tempers and conditions
1065 is also supplied in 8 other conditions. The full side-by-side table is on the 1065 overview.
- HRDefaultDefault stock condition for bar, plate and coil that will be machined and then heat treated.380 MPa yield · 190 HB
- H&T-SpringPre-hardened strip supplied ready to form flat springs, clips, shims and doctor blades — no further heat treatment.1,400 MPa yield · 46 HRC
- Q&TStandard hardened condition for blades, knives, springs and wear parts needing high strength with usable toughness.1,200 MPa yield · 42 HRC
- CDChoose for close size tolerance, straightness and higher as-supplied yield strength without heat treating.635 MPa yield · 220 HB
- SA-CD1065 spheroidize-annealed to a globular carbide structure then cold drawn — better ductility and cold-heading/machining behaviour than as-drawn pearlitic bar at similar strength.530 MPa yield · 187 HB
- CRCold-rolled coil/strip for blanked parts, saw plate and blade blanks that will be hardened after forming.520 MPa yield · 205 HB
- NormalizedPick for uniform fine pearlitic structure and better machined-surface consistency before hardening.420 MPa yield · 200 HB
- AnnealedSoftest general condition; pick it for machining, blanking and stress-free stock before hardening.340 MPa yield · 174 HB
- SAUse for severe cold forming, upsetting or heavy machining of high-carbon stock.320 MPa yield · 160 HB
Working with 1065 H&T-Spring
Is 1065 easy to machine?
Machine annealed or spheroidized with rigid setups, carbide tooling, 60–100 m/min and generous coolant; above ~35 HRC switch to grinding, CBN or EDM.
Can 1065 be welded?
Poor weldability — preheat 200–300 °C, low-hydrogen consumables, minimum restraint and immediate post-weld temper/stress relief to avoid HAZ martensite cracking.
Can 1065 be formed, bent or molded?
Form in the annealed/spheroidized state with generous bend radii (≥2t); hard or tempered strip has little residual ductility and should be roll-formed or blanked, then stress relieved at 250–350 °C.
What surface finishes work on 1065?
No corrosion resistance: use black oxide, manganese/zinc phosphate, oil, zinc or nickel plating (bake to avoid hydrogen embrittlement above 40 HRC), or paint; polishes to a fine edge but must be protected.
1065 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/AISI 1065; EN C67 is 0.65–0.72 | 0.6 – 0.7 | 0.65 |
| Mn | 0.6 – 0.9 | 0.75 |
| Sitypical for killed hot-rolled product; not specified for all forms | 0.15 – 0.35 | 0.25 |
| P | ≤ 0.04 | — |
| S | ≤ 0.05 | — |
| Fe | balance | — |
1065 H&T-Spring — frequently asked
What is 1065 H&T-Spring used for?
1065 H&T-Spring is typically used for coil springs, washers and hand tools. In short: premium high-carbon spring steel.
What is the yield strength of 1065 H&T-Spring?
1065 H&T-Spring has a typical yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 96% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 1065 H&T-Spring easy to machine?
Not especially — machinability is rated poor (20/100, worse than 97% of steel grades). Machine annealed or spheroidized with rigid setups, carbide tooling, 60–100 m/min and generous coolant; above ~35 HRC switch to grinding, CBN or EDM.
Can 1065 H&T-Spring be welded?
Not readily — weldability is rated not recommended (10/100). Poor weldability — preheat 200–300 °C, low-hydrogen consumables, minimum restraint and immediate post-weld temper/stress relief to avoid HAZ martensite cracking.
What surface finishes work on 1065 H&T-Spring?
No corrosion resistance: use black oxide, manganese/zinc phosphate, oil, zinc or nickel plating (bake to avoid hydrogen embrittlement above 40 HRC), or paint; polishes to a fine edge but must be protected.
Can 1065 H&T-Spring be formed, bent or molded?
Form in the annealed/spheroidized state with generous bend radii (≥2t); hard or tempered strip has little residual ductility and should be roll-formed or blanked, then stress relieved at 250–350 °C.
What is the maximum service temperature of 1065 H&T-Spring?
1065 H&T-Spring is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1065-HR and 1065-CD?
HR is the default condition — default stock condition for bar, plate and coil that will be machined and then heat treated. CD: choose for close size tolerance, straightness and higher as-supplied yield strength without heat treating. Yield strength is 380 MPa in HR versus 635 MPa in CD.
Can FabDigit make parts in 1065 H&T-Spring?
Yes — 1065 H&T-Spring 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 J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- ASTM A29/A29M — General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASTM A682/A684 — Hardenable and High-Carbon Cold-Rolled Steel Strip — ASTM (2019)
- EN 10132-4 / EN 10083-2 (C67 / C60E) — CEN (2006)
- 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)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- Carbon steel property compilations (MMPDS/CES typical values) — various (2022)
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.