Steel 25CrMo4 Q&T 40-100

What is 25CrMo4 Q&T 40-100?

25CrMo4 Q&T 40-100 is 25CrMo4 heat treated to Q&T 40-100 — pick for heavier forgings/bars where limited hardenability lowers the guaranteed strength class to 700–850 MPa. 25CrMo4 Q&T 40-100 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 67% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi). 25CrMo4 Q&T 40-100 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). Q&T is the default condition FabDigit quotes; Q&T 40-100 is available on request or by drawing note.

Typical room-temperature values for 25CrMo4 Q&T 40-100 — 12 properties are specific to this condition; the rest are grade-level values shared by every 25CrMo4 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other 25CrMo4 tempers and conditions

25CrMo4 is also supplied in 10 other conditions. The full side-by-side table is on the 25CrMo4 overview.

• Q&TDefaultDefault stocked condition: balanced 800–950 MPa strength with good toughness for shafts, gears and pressure parts.650 MPa yield · 28 HRC
• +CHThrough-quenched and low-temperature tempered condition giving a hard martensitic core (~30–36 HRC) with restricted core hardenability band.900 MPa yield · 34 HRC
• Q&T 28-32 HRCPick when drawings call out a hardness band (shafts, sprockets, sour-service-adjacent pressure parts limited to ≤ 32 HRC).800 MPa yield · 30 HRC
• Q&T ≤16Pick for small shafts, bolts and thin tube where the full 900–1100 MPa strength class of EN 10083-3 is required.780 MPa yield · 31 HRC
• +CPick for close-tolerance bright bar with raised yield and good chip control when no post-machining heat treatment is planned.620 MPa yield · 235 HB
• Q&T 40-100Pick for heavier forgings/bars where limited hardenability lowers the guaranteed strength class to 700–850 MPa.520 MPa yield · 23 HRC
• +NPick for uniform fine-grained structure at moderate strength, typical for weldments and tube that will not be re-quenched.460 MPa yield · 215 HB
• +HGrade variant supplied with a guaranteed end-quench hardenability band (J1.5 ≈ 44–49 HRC); bar is normally delivered soft-annealed or normalized before the customer's own hardening.430 MPa yield · 200 HB
• +APick for maximum machinability and cold forming before the part is heat treated.400 MPa yield · 200 HB
• +SSoft delivery condition heat treated to a low, uniform hardness so that bar can be cold sheared into billets without cracking.380 MPa yield · 185 HB
• +ACSpheroidize-annealed structure with globular carbides in ferrite — the softest and most cold-formable condition, used for cold heading and cold extrusion.330 MPa yield · 170 HB

Working with 25CrMo4 Q&T 40-100

25CrMo4 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.

25CrMo4 Q&T 40-100 — frequently asked

Sources