Steel 5132-QT315
Heat-treated state
AISI/SAE 5132 · UNS G51320
QT315 = q&T 315 °C
Very high strength with slightly better toughness than the 205 °C temper; avoid extended holds (temper embrittlement range above).
Values for the QT315 condition
Other 5132 tempers and conditions
5132 is listed in 10 conditions; see the grade overview at 5132.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Softest, most machinable condition; standard stock form for bar that will be quench-and-tempered later. | 385 | 600 | 22 | 174 HB | — |
Hot rolled | Cheapest mill condition for bar that will be re-heat-treated after machining. | 425 | 690 | 19 | 200 HB | — |
Normalized | Uniform fine-grain structure for forgings before machining or as a moderate-strength delivery condition. | 460 | 720 | 20 | 212 HB | — |
Cold drawn | Choose for close tolerance, straight bar with raised yield strength and good surface finish, no further heat treatment. | 660 | 760 | 13 | 223 HB | — |
Q&T 650 °C | Toughest tempered condition; used for impact-loaded parts and where later welding or heavy machining is needed. | 740 | 850 | 22 | 25 HRC | — |
Induction hardened | Surface-hardened journals, splines and gear teeth: hard wear-resistant case on a tough quenched-and-tempered core. | 900 | 1,050 | 14 | 55 HRC | 6.8 % IACS |
Q&T 540 °C | General-purpose quenched-and-tempered condition — best strength/toughness compromise for shafts and machine parts. | 930 | 1,050 | 17 | 33 HRC | — |
Q&T 425 °C | High-strength condition for gear blanks and heavily loaded shafts needing moderate toughness. | 1,170 | 1,290 | 14 | 41 HRC | — |
QT315This page Q&T 315 °C | Very high strength with slightly better toughness than the 205 °C temper; avoid extended holds (temper embrittlement range above). | 1,390 | 1,550 | 12 | 46 HRC | — |
Q&T 205 °C | Maximum hardness and wear resistance for small pins and wear parts where toughness is secondary. | 1,500 | 1,740 | 10 | 50 HRC | — |
What is 5132-QT315?
5132-QT315 is 5132 heat treated to QT315 — very high strength with slightly better toughness than the 205 °C temper; avoid extended holds (temper embrittlement range above). 5132-QT315 has a yield strength of 1,390 MPa (202 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 96% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi). 5132-QT315 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). A is the default condition FabDigit quotes; QT315 is available on request or by drawing note.
Advantages
- High strength — 1,390 MPa (202 ksi), better than 96% of steel grades
Limitations
- Difficult to machine — 30/100, worse than 89% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
- Limited service temperature — 260°C (500 °F), worse than 82% of steel grades
5132-QT315 properties
Typical room-temperature values for 5132-QT315; 12 are specific to this condition. Other listed values are 5132 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
5132-QT315 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).
Mechanical16
5132-QT315 has a yield strength of 1,390 MPa (202 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 96% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
5132-QT315 is rated for continuous service to 260°C (500 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
5132-QT315 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 5132-QT315 takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability8
5132-QT315's machinability is poor (30/100, worse than 89% of steel grades); weldability fair (45/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 5132-QT315
Is 5132 easy to machine?
Machine in the annealed or ≤32 HRC tempered condition with carbide tooling; rating ≈65 % of 1212, use rigid setups and flood coolant above 40 HRC.
Can 5132 be welded?
Weldable with low-hydrogen consumables but requires 200–300 °C preheat, controlled interpass and immediate post-weld temper to avoid HAZ martensite cracking.
Can 5132 be formed, bent or molded?
Hot forge 1100–1200 °C then normalize; cold forming limited to mild bending of annealed stock due to high carbon.
What surface finishes work on 5132?
No inherent corrosion resistance — apply phosphate + oil, black oxide, zinc plating or hard chrome; bake after plating to avoid hydrogen embrittlement in hardened parts.
5132 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 |
|---|---|---|
| C | 0.3 – 0.35 | 0.32 |
| Mn | 0.6 – 0.8 | 0.7 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.75 – 1 | 0.88 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Fe | balance | — |
5132-QT315 — frequently asked
What is 5132-QT315 used for?
5132-QT315 is typically used for axles, gears, shafts, machine parts and fasteners. In short: best-machining 51xx grade here; stronger than 5130; induction-hardenable Cr steel.
What is the yield strength of 5132-QT315?
5132-QT315 has a typical yield strength of 1,390 MPa (202 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 96% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 5132-QT315 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine in the annealed or ≤32 HRC tempered condition with carbide tooling; rating ≈65 % of 1212, use rigid setups and flood coolant above 40 HRC.
Can 5132-QT315 be welded?
With care — weldability is rated fair (45/100). Weldable with low-hydrogen consumables but requires 200–300 °C preheat, controlled interpass and immediate post-weld temper to avoid HAZ martensite cracking.
What surface finishes work on 5132-QT315?
No inherent corrosion resistance — apply phosphate + oil, black oxide, zinc plating or hard chrome; bake after plating to avoid hydrogen embrittlement in hardened parts.
Can 5132-QT315 be formed, bent or molded?
Hot forge 1100–1200 °C then normalize; cold forming limited to mild bending of annealed stock due to high carbon.
What is the maximum service temperature of 5132-QT315?
5132-QT315 is rated for continuous use to about 260°C (500 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 5132-A and 5132-QT205?
A is the default condition — softest, most machinable condition; standard stock form for bar that will be quench-and-tempered later. QT205: maximum hardness and wear resistance for small pins and wear parts where toughness is secondary. Yield strength is 385 MPa in A versus 1,500 MPa in QT205.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- 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)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
- Mysteel / SMM (2026)
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.