Steel 26CrMo4-2 +QT (Quenched and tempered)
Heat-treated state · default condition
EN 26CrMo4-2
Standard delivery condition for pressure-service bolts and studs; best strength/toughness balance up to about 500 °C.
Values for the +QT condition
Other 26CrMo4-2 tempers and conditions
26CrMo4-2 is listed in 6 conditions; see the grade overview at 26CrMo4-2.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest supply condition for cold heading of bolt blanks and heavy machining before hardening. | 380 | 620 | 22 | 185 HB | — |
Normalized | Uniform ferrite–pearlite structure for forged blanks that will be re-hardened or used at moderate loads. | 430 | 680 | 20 | 200 HB | — |
Cold drawn | Cold-drawn bright bar for close tolerance blanks and automatic-lathe parts before final hardening. | 620 | 760 | 11 | 20 HRC | 8 % IACS |
sour-service / NACE MR0175 limited hardness | High-temper condition with hardness capped at 22 HRC for H₂S-containing (sour) bolting service. | 640 | 810 | 19 | 20 HRC | — |
+QTDefaultThis page Quenched and tempered | Standard delivery condition for pressure-service bolts and studs; best strength/toughness balance up to about 500 °C. | 700 | 880 | 17 | 26 HRC | — |
+QT high strength | Higher tempering-strength variant for property class 10.9 bolts where preload capacity matters more than toughness. | 900 | 1,010 | 12 | 33 HRC | — |
What is 26CrMo4-2 +QT?
26CrMo4-2 +QT is 26CrMo4-2 heat treated to +QT — standard delivery condition for pressure-service bolts and studs; best strength/toughness balance up to about 500 °C. 26CrMo4-2 +QT has a yield strength of 700 MPa (102 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi). 26CrMo4-2 +QT 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).
Advantages
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
26CrMo4-2 +QT properties
Typical room-temperature values for 26CrMo4-2 +QT; 16 are specific to this condition. Other listed values are 26CrMo4-2 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
26CrMo4-2 +QT 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
26CrMo4-2 +QT has a yield strength of 700 MPa (102 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
26CrMo4-2 +QT is rated for continuous service to 500°C (932 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
26CrMo4-2 +QT 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 26CrMo4-2 +QT takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
26CrMo4-2 +QT's machinability is fair (52/100, better than 52% of steel grades); weldability fair (50/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 26CrMo4-2 +QT
Is 26CrMo4-2 easy to machine?
Machines best at 200–260 HB with carbide inserts and rigid setups; above 30 HRC use coated carbide/CBN, reduce speed ~30 %.
Can 26CrMo4-2 be welded?
Weldable with low-hydrogen or matching Cr-Mo consumables; preheat 200–300 °C and PWHT/temper at 620–680 °C to avoid hard HAZ cracking.
Can 26CrMo4-2 be formed, bent or molded?
Cold head or roll threads only in annealed/spheroidized condition; hot forge 1100–850 °C then normalize before quench and temper.
What surface finishes work on 26CrMo4-2?
No natural corrosion protection — use zinc or Zn-Ni plating (bake for hydrogen relief), phosphate + oil, Dacromet or paint; hard chrome and nitriding also possible.
26CrMo4-2 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 |
|---|---|---|
| Cmedium carbon for hardenability with weldability | 0.22 – 0.29 | 0.26 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| Pimpurity | ≤ 0.03 | 0.01 |
| Slow S for fastener toughness | ≤ 0.02 | 0.01 |
| Cr | 0.9 – 1.2 | 1.05 |
| Motemper-embrittlement resistance, creep at 400–500 °C | 0.15 – 0.3 | 0.22 |
| Niresidual | ≤ 0.4 | 0.1 |
| Algrain refining, fine-grain practice | 0.02 – 0.05 | 0.03 |
| Fe | balance | — |
26CrMo4-2 +QT — frequently asked
What is 26CrMo4-2 +QT used for?
26CrMo4-2 +QT is typically used for high-strength bolts, fasteners and studs. In short: fastener-grade Cr-Mo steel; good hardenability at moderate carbon; 500 °C service capability.
What is the yield strength of 26CrMo4-2 +QT?
26CrMo4-2 +QT has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 26CrMo4-2 +QT easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines best at 200–260 HB with carbide inserts and rigid setups; above 30 HRC use coated carbide/CBN, reduce speed ~30 %.
Can 26CrMo4-2 +QT be welded?
With care — weldability is rated fair (50/100). Weldable with low-hydrogen or matching Cr-Mo consumables; preheat 200–300 °C and PWHT/temper at 620–680 °C to avoid hard HAZ cracking.
What surface finishes work on 26CrMo4-2 +QT?
No natural corrosion protection — use zinc or Zn-Ni plating (bake for hydrogen relief), phosphate + oil, Dacromet or paint; hard chrome and nitriding also possible.
Can 26CrMo4-2 +QT be formed, bent or molded?
Cold head or roll threads only in annealed/spheroidized condition; hot forge 1100–850 °C then normalize before quench and temper.
What is the maximum service temperature of 26CrMo4-2 +QT?
26CrMo4-2 +QT is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 26CrMo4-2 +QT and 26CrMo4-2 QT-900?
+QT is the default condition — standard delivery condition for pressure-service bolts and studs; best strength/toughness balance up to about 500 °C. QT-900: higher tempering-strength variant for property class 10.9 bolts where preload capacity matters more than toughness. Yield strength is 700 MPa in +QT versus 900 MPa in QT-900.
Sources
- EN 10269 — Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties — CEN (2013)
- EN 10083-3 — Heat treatable steels: alloy steels (25CrMo4/34CrMo4 comparison data) — CEN (2006)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- Cr-Mo bolting steel bar datasheets (1.7218/1.7219/1.7220 class) — European special steel producers (2022)
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.