Steel 1075 · heat-treated state
Steel 1075 Q&T
Properties of the Q&T condition, compared with the other 1075 tempers.
General hardened-and-tempered condition (~400–450 °C temper) balancing spring strength with usable toughness.
What is 1075 Q&T?
1075 Q&T is 1075 heat treated to Q&T — general hardened-and-tempered condition (~400–450 °C temper) balancing spring strength with usable toughness. 1075 Q&T has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Elongation at break is 8% and the elastic modulus is 205 GPa (29.7 Msi). 1075 Q&T 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; Q&T is available on request or by drawing note.
Advantages
- High strength — 1,300 MPa (189 ksi), better than 95% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
Limitations
- Difficult to weld — 10/100, worse than 99% of steel grades
- Difficult to machine — 20/100, worse than 97% of steel grades
- Limited formability — 8/100, worse than 97% of steel grades
- Limited ductility — 8%, worse than 95% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
1075 Q&T properties
Typical room-temperature values for 1075 Q&T — 15 properties are specific to this condition; the rest are grade-level values shared by every 1075 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1075 Q&T 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).
Mechanical14
1075 Q&T has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Elongation at break is 8% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1075 Q&T is rated for continuous service to 250°C (482 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
1075 Q&T conducts electricity at 9.5 % IACS, better than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (8/100), worse than 99% of steel grades.
Sustainability4
Producing a kilogram of 1075 Q&T takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 28%.
Manufacturability8
1075 Q&T's machinability is poor (20/100, worse than 97% of steel grades); weldability not recommended (10/100); formability not recommended (8/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1075 tempers and conditions
1075 is also supplied in 9 other conditions. The full side-by-side table is on the 1075 overview.
- HRDefaultMost commonly stocked mill condition for plate, flat bar and coil that will be re-heat-treated by the user.470 MPa yield · 235 HB
- Q&T 56-60 HRCQuench (water/fast oil) plus 175–200 °C temper for knives, saw teeth and springs needing maximum edge retention; brittle in thick or notched sections.1,700 MPa yield · 58 HRC
- Q&T 50-54 HRCUse for impact tools, machetes, chisels and heavy blades where toughness matters more than peak edge hardness.1,550 MPa yield · 52 HRC
- OTContinuously austenitized, oil-quenched and tempered wire for coil springs — coil directly, no post-heat treatment beyond stress relief.1,400 MPa yield · 47 HRC
- Q&TGeneral hardened-and-tempered condition (~400–450 °C temper) balancing spring strength with usable toughness.1,300 MPa yield · 45 HRC
- Q&T 40-45 HRCPick for flat springs, clips, feeler and saw stock needing fatigue life and some bendability.1,200 MPa yield · 43 HRC
- CRCold-rolled strip for shims, blades and flat springs that are formed and then hardened, or used as-rolled where high yield is enough.900 MPa yield · 30 HRC
- CDCold-drawn bar and hard-drawn wire: tighter tolerance, better surface and higher yield than hot rolled.830 MPa yield · 29 HRC
- NormalizedUse to refine grain and homogenize fine pearlite before machining or hardening; higher strength than annealed.530 MPa yield · 28 HRC
- AnnealedChoose for maximum machinability, deep drawing or cold forming before hardening.400 MPa yield · 185 HB
Working with 1075 Q&T
Is 1075 easy to machine?
Machine in the annealed or spheroidized state with rigid setups and carbide tooling; hardened material above ~50 HRC needs grinding or EDM.
Can 1075 be welded?
Poor weldability (CE ≈ 0.9): if unavoidable, preheat 250–350 °C, use low-hydrogen consumables and temper immediately after welding.
Can 1075 be formed, bent or molded?
Cold form only when annealed or in thin strip; hot work 850–1100 °C, harden from 790–830 °C (water/brine for thin, fast oil for thicker), temper 175–450 °C to target hardness.
What surface finishes work on 1075?
No corrosion resistance — protect with oil, black oxide/bluing, phosphate, zinc plating or paint; polishes to a bright finish when hardened.
1075 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 75: 0.72–0.80 | 0.7 – 0.8 | 0.75 |
| MnGB 75: 0.50–0.80 | 0.4 – 0.7 | 0.55 |
| Sikilled steel; not specified for rimmed AISI heats, GB 75: 0.17–0.37 | 0.1 – 0.35 | 0.25 |
| P | ≤ 0.04 | — |
| Smax (ASTM A29 bar) | ≤ 0.05 | — |
| Fe | balance | — |
1075 Q&T — frequently asked
What is 1075 Q&T used for?
1075 Q&T is typically used for clutch plates, spring clips and blades. In short: high hardness; blade steel.
What is the yield strength of 1075 Q&T?
1075 Q&T has a typical yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 1075 Q&T easy to machine?
Not especially — machinability is rated poor (20/100, worse than 97% of steel grades). Machine in the annealed or spheroidized state with rigid setups and carbide tooling; hardened material above ~50 HRC needs grinding or EDM.
Can 1075 Q&T be welded?
Not readily — weldability is rated not recommended (10/100). Poor weldability (CE ≈ 0.9): if unavoidable, preheat 250–350 °C, use low-hydrogen consumables and temper immediately after welding.
What surface finishes work on 1075 Q&T?
No corrosion resistance — protect with oil, black oxide/bluing, phosphate, zinc plating or paint; polishes to a bright finish when hardened.
Can 1075 Q&T be formed, bent or molded?
Cold form only when annealed or in thin strip; hot work 850–1100 °C, harden from 790–830 °C (water/brine for thin, fast oil for thicker), temper 175–450 °C to target hardness.
What is the maximum service temperature of 1075 Q&T?
1075 Q&T 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 1075-HR and 1075-OT?
HR is the default condition — most commonly stocked mill condition for plate, flat bar and coil that will be re-heat-treated by the user. OT: continuously austenitized, oil-quenched and tempered wire for coil springs — coil directly, no post-heat treatment beyond stress relief. Yield strength is 470 MPa in HR versus 1,400 MPa in OT.
Can FabDigit make parts in 1075 Q&T?
Yes — 1075 Q&T 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)
- ASTM A682/A684 — High-Carbon Cold-Rolled Spring Steel Strip — ASTM (2018)
- ASTM A229 / A230 — Oil-Tempered Carbon Steel Spring Wire — 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)
- Mysteel / SMM (2025)
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.