Steel X15CrMo5-1 QT-BOLT
Heat-treated state
EN X15CrMo5-1 · ASTM A182 F5
QT-BOLT = +QT bolting condition
Bar/rod for high-temperature studs and bolts where relaxation resistance at 480–550 °C governs.
Values for the QT-BOLT condition
Other X15CrMo5-1 tempers and conditions
X15CrMo5-1 is listed in 5 conditions; see the grade overview at X15CrMo5-1.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition for heavy machining or cold work before final N+T. | 330 | 550 | 26 | 170 HB | — |
NTDefault normalized ~950 °C and tempered 700–760 °C (ASTM A182 F5) | Standard stocked condition for high-temperature valves, flanges and fittings; balanced creep strength and toughness. | 470 | 660 | 22 | 15 HRC | — |
As-forged / hot rolled | Mill-supplied semi-finished bar or forging blank; properties non-uniform, always heat treated before use. | 480 | 700 | 18 | 22 HRC | 3.1 % IACS |
QT-BOLTThis page +QT bolting condition | Bar/rod for high-temperature studs and bolts where relaxation resistance at 480–550 °C governs. | 580 | 750 | 18 | 22 HRC | 3.1 % IACS |
Quenched and tempered | Choose when higher room-temperature strength/hardness is needed (F5a class); slightly lower toughness. | 590 | 760 | 19 | 23 HRC | — |
What is X15CrMo5-1 QT-BOLT?
X15CrMo5-1 QT-BOLT is X15CrMo5-1 heat treated to QT-BOLT — bar/rod for high-temperature studs and bolts where relaxation resistance at 480–550 °C governs. X15CrMo5-1 QT-BOLT has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 75% of steel grades. Elongation at break is 18% and the elastic modulus is 213 GPa (30.9 Msi). X15CrMo5-1 QT-BOLT has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,425°C (2,597 °F). NT is the default condition FabDigit quotes; QT-BOLT is available on request or by drawing note.
Advantages
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
- Good corrosion resistance — 25/100, better than 92% of steel grades
- High strength — 580 MPa (84.1 ksi), better than 75% of steel grades
Limitations
- Low electrical conductivity — 3.1 % IACS, worse than 89% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
- Difficult to machine — 40/100, worse than 77% of steel grades
X15CrMo5-1 QT-BOLT properties
Typical room-temperature values for X15CrMo5-1 QT-BOLT; 23 are specific to this condition. Other listed values are X15CrMo5-1 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
X15CrMo5-1 QT-BOLT has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
X15CrMo5-1 QT-BOLT has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 75% of steel grades. Elongation at break is 18% and the elastic modulus is 213 GPa (30.9 Msi).
Thermal6
X15CrMo5-1 QT-BOLT is rated for continuous service to 550°C (1,022 °F). It conducts heat at 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 73% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
X15CrMo5-1 QT-BOLT conducts electricity at 3.1 % IACS, worse than 89% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of X15CrMo5-1 QT-BOLT takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
X15CrMo5-1 QT-BOLT's machinability is fair (40/100, worse than 77% of steel grades); weldability fair (40/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with X15CrMo5-1 QT-BOLT
Is X15CrMo5-1 easy to machine?
Machine in the annealed or N+T state with rigid setups and carbide tooling; work-hardening is mild but the 5 % Cr matrix is abrasive — moderate speeds and generous coolant.
Can X15CrMo5-1 be welded?
Weldable with matching 5Cr-0.5Mo (E8018-B6 / ER80S-B6) filler; preheat 200–300 °C, maintain interpass and apply 700–760 °C PWHT to avoid hard martensite and hydrogen cracking.
Can X15CrMo5-1 be formed, bent or molded?
A hot-working grade: forge at 1100–1200 °C, finish above 900 °C, slow cool; cold forming limited to gentle bends after annealing.
What surface finishes work on X15CrMo5-1?
Not stainless — protect with high-temperature aluminium paint, phosphating, aluminizing or 12Cr/Alloy 625 weld overlay for wet or corrosive service.
X15CrMo5-1 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≤0.15 per ASTM A182 F5 | 0.1 – 0.18 | 0.15 |
| Si | ≤ 0.5 | 0.3 |
| Mn | 0.3 – 0.6 | 0.45 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Cr | 4 – 6 | 5 |
| Mosome EN listings of X15CrMo5-1 allow up to ~1.0 % Mo; confirm with mill certificate | 0.45 – 0.65 | 0.55 |
| Ni | ≤ 0.5 | — |
| Fe | balance | — |
X15CrMo5-1 QT-BOLT — frequently asked
What is X15CrMo5-1 QT-BOLT used for?
X15CrMo5-1 QT-BOLT is typically used for valve bodies, high-temperature flanges and process piping. In short: creep-resistant 5Cr-1Mo steel; 600 °C service capability; standard valve forging grade.
What is the yield strength of X15CrMo5-1 QT-BOLT?
X15CrMo5-1 QT-BOLT has a typical yield strength of 580 MPa (84.1 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 75% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is X15CrMo5-1 QT-BOLT easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Machine in the annealed or N+T state with rigid setups and carbide tooling; work-hardening is mild but the 5 % Cr matrix is abrasive — moderate speeds and generous coolant.
Can X15CrMo5-1 QT-BOLT be welded?
With care — weldability is rated fair (40/100). Weldable with matching 5Cr-0.5Mo (E8018-B6 / ER80S-B6) filler; preheat 200–300 °C, maintain interpass and apply 700–760 °C PWHT to avoid hard martensite and hydrogen cracking.
What surface finishes work on X15CrMo5-1 QT-BOLT?
Not stainless — protect with high-temperature aluminium paint, phosphating, aluminizing or 12Cr/Alloy 625 weld overlay for wet or corrosive service.
Can X15CrMo5-1 QT-BOLT be formed, bent or molded?
A hot-working grade: forge at 1100–1200 °C, finish above 900 °C, slow cool; cold forming limited to gentle bends after annealing.
What is the maximum service temperature of X15CrMo5-1 QT-BOLT?
X15CrMo5-1 QT-BOLT is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between X15CrMo5-1-NT and X15CrMo5-1-A?
NT is the default condition — standard stocked condition for high-temperature valves, flanges and fittings; balanced creep strength and toughness. A: softest condition for heavy machining or cold work before final N+T. Yield strength is 470 MPa in NT versus 330 MPa in A.
Sources
- ASTM A182/A182M — Forged or Rolled Alloy Pipe Flanges, Fittings, Valves (Grade F5/F5a) — ASTM International (2023)
- EN 10222-2 — Steel forgings for pressure purposes, ferritic and martensitic creep-resisting steels — CEN (2017)
- EN 10269 — Steels and nickel alloys for fasteners with specified elevated/low temperature properties — CEN (2013)
- ASME BPVC Section II Part D — Material Properties (5Cr-0.5Mo) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- API RP 941 — Steels for Hydrogen Service at Elevated Temperatures — API (2016)
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.