Steel 1547 QT-40HRC
Hardness band
AISI/SAE 1547 · UNS G15470
QT-40HRC = q&T
Higher-strength temper for wear-loaded pins, links and rack teeth where toughness demand is moderate.
Values for the QT-40HRC condition
Other 1547 tempers and conditions
1547 is listed in 8 conditions; see the grade overview at 1547.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition — choose for deep machining, cold heading blanks or before severe forming. | 345 | 620 | 20 | 179 HB | — |
Hot rolled | Lowest-cost bar for parts that will be fully machined or later heat treated. | 386 | 703 | 9 | 207 HB | — |
Normalized | Refines the hot-rolled structure for uniform hardness and better response to later quenching. | 435 | 760 | 12 | 223 HB | — |
Annealed and Cold Drawn | Anneal before drawing gives lower residual stress and better ductility/straightness than as-rolled cold drawn. | 620 | 745 | 11 | 217 HB | — |
Induction hardened | Selective surface hardening of journals/teeth on a tough core — the main reason the 15xx high-Mn carbon grades are chosen. | 620 | 900 | 10 | 57 HRC | — |
CDDefault Cold drawn | Standard stocked bar: highest as-supplied strength, tight tolerance and bright finish for turned shafts and pins. | 724 | 827 | 8 | 241 HB | — |
Q&T | Balanced strength/toughness condition for shafts, rods and highly loaded machined parts. | 760 | 950 | 15 | 30 HRC | — |
QT-40HRCThis page Q&T | Higher-strength temper for wear-loaded pins, links and rack teeth where toughness demand is moderate. | 1,070 | 1,240 | 11 | 40 HRC | — |
What is 1547 QT-40HRC?
1547 QT-40HRC is 1547 heat treated to QT-40HRC — higher-strength temper for wear-loaded pins, links and rack teeth where toughness demand is moderate. 1547 QT-40HRC has a yield strength of 1,070 MPa (155 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 93% of steel grades. Elongation at break is 11% and the elastic modulus is 200 GPa (29 Msi). 1547 QT-40HRC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). CD is the default condition FabDigit quotes; QT-40HRC is available on request or by drawing note.
Advantages
- High strength — 1,070 MPa (155 ksi), better than 93% of steel grades
- Conducts heat well — 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades
- High electrical conductivity — 9.5 % IACS, better than 75% of steel grades
Limitations
- Difficult to weld — 10/100, worse than 99% of steel grades
- Limited ductility — 11%, worse than 89% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
- Limited formability — 20/100, worse than 80% of steel grades
1547 QT-40HRC properties
Typical room-temperature values for 1547 QT-40HRC; 12 are specific to this condition. Other listed values are 1547 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1547 QT-40HRC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical17
1547 QT-40HRC has a yield strength of 1,070 MPa (155 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 93% of steel grades. Elongation at break is 11% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1547 QT-40HRC is rated for continuous service to 400°C (752 °F). It conducts heat at 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1547 QT-40HRC conducts electricity at 9.5 % IACS, better than 75% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 1547 QT-40HRC takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
1547 QT-40HRC's machinability is poor (30/100, worse than 89% of steel grades); weldability not recommended (10/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1547 QT-40HRC
Is 1547 easy to machine?
Machines like a medium-carbon steel at ~55 % of 1212 — use rigid setups, carbide at 90–140 m/min, and expect better chip control in the cold-drawn or spheroidize-annealed condition.
Can 1547 be welded?
Poor weldability (CE ≈ 0.75): preheat 200–260 °C, low-hydrogen consumables and post-weld stress relief/temper are needed to avoid HAZ martensite cracking.
Can 1547 be formed, bent or molded?
Cold formability is limited by carbon and Mn — bend generously (≥3t) after anneal, or hot form at 900–1200 °C; ideal for hot upsetting and roll forming of blanks.
What surface finishes work on 1547?
No corrosion resistance: use oiling, manganese/zinc phosphate, black oxide, zinc or hard-chrome plating; polishes well after quench-and-temper for a fine, uniform structure.
1547 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 G15470 | 0.43 – 0.51 | 0.47 |
| Mnhigh-Mn 15xx series | 1.35 – 1.65 | 1.5 |
| Sitypical for killed bar; not specified for some product forms | 0.15 – 0.35 | 0.25 |
| P | ≤ 0.03 | 0.02 |
| Smax; resulfurized 11xx/12xx-type variants order S to a range | ≤ 0.05 | 0.03 |
| Fe | balance | — |
1547 QT-40HRC — frequently asked
What is 1547 QT-40HRC used for?
1547 QT-40HRC is typically used for machine shafts, spline shafts and wear-resistant machined components. In short: wear-resistant free-machining grade; harder than 1541; poor weldability, CE about 0.75.
What is the yield strength of 1547 QT-40HRC?
1547 QT-40HRC has a typical yield strength of 1,070 MPa (155 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 93% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 1547 QT-40HRC easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machines like a medium-carbon steel at ~55 % of 1212 — use rigid setups, carbide at 90–140 m/min, and expect better chip control in the cold-drawn or spheroidize-annealed condition.
Can 1547 QT-40HRC be welded?
Not readily — weldability is rated not recommended (10/100). Poor weldability (CE ≈ 0.75): preheat 200–260 °C, low-hydrogen consumables and post-weld stress relief/temper are needed to avoid HAZ martensite cracking.
What surface finishes work on 1547 QT-40HRC?
No corrosion resistance: use oiling, manganese/zinc phosphate, black oxide, zinc or hard-chrome plating; polishes well after quench-and-temper for a fine, uniform structure.
Can 1547 QT-40HRC be formed, bent or molded?
Cold formability is limited by carbon and Mn — bend generously (≥3t) after anneal, or hot form at 900–1200 °C; ideal for hot upsetting and roll forming of blanks.
What is the maximum service temperature of 1547 QT-40HRC?
1547 QT-40HRC 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 1547-CD and 1547-A?
CD is the default condition — standard stocked bar: highest as-supplied strength, tight tolerance and bright finish for turned shafts and pins. A: softest condition — choose for deep machining, cold heading blanks or before severe forming. Yield strength is 724 MPa in CD versus 345 MPa in A.
Sources
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements — ASTM (2020)
- ASTM A108 — Steel Bar, Carbon and Alloy, Cold-Finished — ASTM (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook (machinability ratings, heat treatment of carbon steels) — Industrial Press (2020)
- SAE/ASM carbon steel bar mechanical property tables — ASM International (2001)
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.