Steel 4037 QT-32-36HRC
Hardness band
AISI/SAE 4037 · UNS G40370
Higher-strength Q&T level typical of SAE J429 Grade 8 / ASTM A354 BC fastener requirements.
Values for the QT-32-36HRC condition
Other 4037 tempers and conditions
4037 is listed in 8 conditions; see the grade overview at 4037.
- HR
- A
- N
- CD
- QT-22-26HRC
- QT-28-32HRC
- QT-32-36HRC
- QT-40-45HRC
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled | Cheapest mill condition for parts that will be heat treated after rough machining or forging. | 380 | 620 | 22 | 179 HB | — |
Solution annealed | Softest, most machinable and most formable condition; use before quench and temper or for cold heading stock. | 400 | 585 | 27 | 170 HB | — |
Normalized | Uniform fine-grain structure and mid-range strength for forgings and weld fabrications not requiring full Q&T. | 450 | 690 | 22 | 200 HB | — |
Cold drawn | Close-tolerance bright bar with raised yield strength for shafts and screw-machine work with no further heat treatment. | 585 | 690 | 15 | 200 HB | — |
quenched and tempered, ~250 HB | Toughest Q&T level; choose for shock-loaded shafts and couplings where impact matters more than strength. | 700 | 830 | 20 | 24 HRC | — |
QT-28-32HRCDefault quenched and tempered, ~285 HB | Standard general-purpose condition for machined shafts, studs and high-strength fasteners. | 860 | 965 | 18 | 30 HRC | — |
QT-32-36HRCThis page quenched and tempered, ~320 HB | Higher-strength Q&T level typical of SAE J429 Grade 8 / ASTM A354 BC fastener requirements. | 965 | 1,080 | 15 | 34 HRC | — |
quenched and low-temperature tempered | Maximum-strength condition for small wear parts and pins; reduced ductility and notch sensitivity must be accepted. | 1,240 | 1,380 | 12 | 42 HRC | — |
What is 4037 QT-32-36HRC?
4037 QT-32-36HRC is 4037 heat treated to QT-32-36HRC — higher-strength Q&T level typical of SAE J429 Grade 8 / ASTM A354 BC fastener requirements. 4037 QT-32-36HRC has a yield strength of 965 MPa (140 ksi) and a tensile strength of 1,080 MPa (157 ksi) — stronger than 91% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi). 4037 QT-32-36HRC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F). QT-28-32HRC is the default condition FabDigit quotes; QT-32-36HRC is available on request or by drawing note.
Advantages
- High strength — 965 MPa (140 ksi), better than 91% of steel grades
Limitations
- Limited formability — 20/100, worse than 80% of steel grades
4037 QT-32-36HRC properties
Typical room-temperature values for 4037 QT-32-36HRC; 13 are specific to this condition. Other listed values are 4037 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4037 QT-32-36HRC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F).
Mechanical16
4037 QT-32-36HRC has a yield strength of 965 MPa (140 ksi) and a tensile strength of 1,080 MPa (157 ksi) — stronger than 91% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4037 QT-32-36HRC is rated for continuous service to 400°C (752 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
4037 QT-32-36HRC conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 4037 QT-32-36HRC takes about 31 MJ of energy and emits 2.2 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 25%.
Manufacturability7
4037 QT-32-36HRC's machinability is fair (45/100, worse than 65% of steel grades); weldability fair (50/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4037 QT-32-36HRC
Is 4037 easy to machine?
Machine in the annealed or ≤32 HRC Q&T condition with coated carbide, ~120–180 m/min; above 36 HRC expect tool wear and prefer grinding or hard turning with CBN.
Can 4037 be welded?
Weldable with low-hydrogen consumables but the ~0.37 %C requires 200–300 °C preheat, interpass control and post-weld temper/stress relief to avoid HAZ cracking.
Can 4037 be formed, bent or molded?
Cold heading and bending are practical only in the annealed/spheroidized state; hot forge 1200 °C down to ~950 °C then normalize before quench and temper.
What surface finishes work on 4037?
No inherent corrosion resistance — specify zinc, zinc-nickel or chrome plating, black oxide, phosphate-and-oil or paint; bake after plating at ≥190 °C to relieve hydrogen embrittlement above 32 HRC.
4037 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 | 0.35 – 0.4 | 0.37 |
| Mn | 0.7 – 0.9 | 0.8 |
| Si | 0.15 – 0.35 | 0.25 |
| Mo | 0.2 – 0.3 | 0.25 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Fe | balance | — |
4037 QT-32-36HRC — frequently asked
What is 4037 QT-32-36HRC used for?
4037 QT-32-36HRC is typically used for bolts, studs, shafts and gears. In short: strongest 40xx moly grade; wide Q&T hardness range; good strength-to-cost ratio.
What is the yield strength of 4037 QT-32-36HRC?
4037 QT-32-36HRC has a typical yield strength of 965 MPa (140 ksi) and a tensile strength of 1,080 MPa (157 ksi) — stronger than 91% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 4037 QT-32-36HRC easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed or ≤32 HRC Q&T condition with coated carbide, ~120–180 m/min; above 36 HRC expect tool wear and prefer grinding or hard turning with CBN.
Can 4037 QT-32-36HRC be welded?
With care — weldability is rated fair (50/100). Weldable with low-hydrogen consumables but the ~0.37 %C requires 200–300 °C preheat, interpass control and post-weld temper/stress relief to avoid HAZ cracking.
What surface finishes work on 4037 QT-32-36HRC?
No inherent corrosion resistance — specify zinc, zinc-nickel or chrome plating, black oxide, phosphate-and-oil or paint; bake after plating at ≥190 °C to relieve hydrogen embrittlement above 32 HRC.
Can 4037 QT-32-36HRC be formed, bent or molded?
Cold heading and bending are practical only in the annealed/spheroidized state; hot forge 1200 °C down to ~950 °C then normalize before quench and temper.
What is the maximum service temperature of 4037 QT-32-36HRC?
4037 QT-32-36HRC 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 4037 QT-28-32HRC and 4037-HR?
QT-28-32HRC is the default condition — standard general-purpose condition for machined shafts, studs and high-strength fasteners. HR: cheapest mill condition for parts that will be heat treated after rough machining or forging. Yield strength is 860 MPa in QT-28-32HRC versus 380 MPa in HR.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J429 — Mechanical and Material Requirements for Externally Threaded Fasteners — SAE International (2014)
- ASTM A322 — Standard Specification for Steel Bars, Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4A — Steel Heat Treating Fundamentals and Processes — ASM International (2013)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
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.