Stainless Steel 403 · heat-treated state
Stainless Steel 403 Q&T 620C Temper
Properties of the Q&T 620C Temper condition, compared with the other 403 tempers.
Choose when maximum toughness and steam-side stability matter more than strength (long blades, thick sections).
What is 403 Q&T 620C Temper?
403 Q&T 620C Temper is 403 heat treated to Q&T 620C Temper — choose when maximum toughness and steam-side stability matter more than strength (long blades, thick sections). 403 Q&T 620C Temper has a yield strength of 585 MPa (84.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 23% and the elastic modulus is 200 GPa (29 Msi). 403 Q&T 620C Temper has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 66% of stainless steel grades. It melts at 1,480°C (2,696 °F). Hardened & Tempered is the default condition FabDigit quotes; Q&T 620C Temper is available on request or by drawing note.
Advantages
- High electrical conductivity — 3 % IACS, better than 95% of stainless steel grades
- Conducts heat well — 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 88% of stainless steel grades
- High strength — 585 MPa (84.8 ksi), better than 86% of stainless steel grades
- Low embodied carbon — 3.8 kg CO₂/kg, better than 77% of stainless steel grades
Limitations
- Low fracture toughness — 70 MPa·√m (63.7 ksi·√in), worse than 87% of stainless steel grades
- Difficult to weld — 35/100, worse than 86% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
- Limited formability — 25/100, worse than 79% of stainless steel grades
403 Q&T 620C Temper properties
Typical room-temperature values for 403 Q&T 620C Temper — 10 properties are specific to this condition; the rest are grade-level values shared by every 403 temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
403 Q&T 620C Temper has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 66% of stainless steel grades. It melts at 1,480°C (2,696 °F).
Mechanical16
403 Q&T 620C Temper has a yield strength of 585 MPa (84.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 23% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
403 Q&T 620C Temper is rated for continuous service to 565°C (1,049 °F). It conducts heat at 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 88% of stainless steel grades. Thermal expansion is 9.9 µm/m·K (5.5 µin/in·°F).
Electrical3
403 Q&T 620C Temper conducts electricity at 3 % IACS, better than 95% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of 403 Q&T 620C Temper takes about 48 MJ of energy and emits 3.8 kg of CO₂ — less than 85% of stainless steel grades. Typical recycled content is 60%.
Manufacturability8
403 Q&T 620C Temper's machinability is fair (42/100, better than 79% of stainless steel grades); weldability fair (35/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 403 tempers and conditions
403 is also supplied in 4 other conditions. The full side-by-side table is on the 403 overview.
- Hardened & TemperedDefaultStandard supply condition for turbine blades and shafts: balanced strength, ductility and steam corrosion resistance.655 MPa yield · 26 HRC
- Q&T 205C TemperChoose for wear parts, valve trim and cutting/knife-type components where hardness beats toughness.1,000 MPa yield · 41 HRC
- Q&T 620C TemperChoose when maximum toughness and steam-side stability matter more than strength (long blades, thick sections).585 MPa yield · 22 HRC
- Cold DrawnChoose for straight, size-tolerant bar stock with higher as-supplied strength and good surface finish.550 MPa yield · 200 HB
- AnnealedChoose for maximum machinability, cold forming and bending before heat treatment.290 MPa yield · 155 HB
Working with 403 Q&T 620C Temper
Is 403 easy to machine?
Machine in the annealed or high-tempered condition with sharp, rigid tooling, positive rake and generous coolant; expect ~45–55% of AISI 1212 rates and stringy chips below 25 HRC.
Can 403 be welded?
Weldable by GTAW/SMAW with 410/410NiMo filler but requires 200–300 °C preheat, controlled interpass and 650–750 °C post-weld temper to avoid hard, crack-prone martensite in the HAZ.
Can 403 be formed, bent or molded?
Cold-form only in the annealed state with generous bend radii (≥2t); hot work 1150–1200 °C, stop above ~900 °C, then slow-cool or anneal to avoid quench cracking.
What surface finishes work on 403?
Passivate (ASTM A967 nitric or citric) after machining; takes a fine mechanical or electropolished finish, and can be hard chrome plated or nitrided for wear service — do not anodize.
403 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 | 0.12 |
| Mn | ≤ 1 | 0.5 |
| Silower than 410 — key distinction of 403 | ≤ 0.5 | 0.3 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 11.5 – 13 | 12.2 |
| Nirestricted in turbine-quality practice | ≤ 0.5 | 0.3 |
| Fe | balance | — |
403 Q&T 620C Temper — frequently asked
What is 403 Q&T 620C Temper used for?
403 Q&T 620C Temper is typically used for steam turbine blades, axial compressor blades, turbine blade forgings and roots, valve bodies and valve trim, pump shafts and high-temperature bolting. In short: hardenable martensitic forging.
What is the yield strength of 403 Q&T 620C Temper?
403 Q&T 620C Temper has a typical yield strength of 585 MPa (84.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 86% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 403 Q&T 620C Temper easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Machine in the annealed or high-tempered condition with sharp, rigid tooling, positive rake and generous coolant; expect ~45–55% of AISI 1212 rates and stringy chips below 25 HRC.
Can 403 Q&T 620C Temper be welded?
With care — weldability is rated fair (35/100). Weldable by GTAW/SMAW with 410/410NiMo filler but requires 200–300 °C preheat, controlled interpass and 650–750 °C post-weld temper to avoid hard, crack-prone martensite in the HAZ.
What surface finishes work on 403 Q&T 620C Temper?
Passivate (ASTM A967 nitric or citric) after machining; takes a fine mechanical or electropolished finish, and can be hard chrome plated or nitrided for wear service — do not anodize.
Can 403 Q&T 620C Temper be formed, bent or molded?
Cold-form only in the annealed state with generous bend radii (≥2t); hot work 1150–1200 °C, stop above ~900 °C, then slow-cool or anneal to avoid quench cracking.
What is the maximum service temperature of 403 Q&T 620C Temper?
403 Q&T 620C Temper is rated for continuous use to about 565°C (1,049 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 403 Q&T 620C Temper?
Yes — 403 Q&T 620C Temper is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A276/A276M Stainless Steel Bars and Shapes — ASTM (2023)
- ASTM A484/A484M General Requirements for Stainless Steel Bars, Billets and Forgings — ASTM (2022)
- EN 10088-1 Stainless steels — List of stainless steels (X6Cr13, 1.4000) — CEN (2014)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- GB/T 1220 (1Cr12 / 12Cr13 ) — SAC (2007)
- SMM / Mysteel (2025)
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.