Stainless Steel 415
AISI/SAE 415 · UNS S41500 · ASTM A487 Gr CA6NM
415 is a low-carbon Ni-Mo "soft martensitic" stainless (UNS S41500), the wrought counterpart to cast CA6NM of ASTM A487, combining high toughness with good weldability.
Reference datasheet — 415 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT780 condition
415 tempers and conditions
415 is supplied in 7 conditions, soft to hard. QT780 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Quenched and tempered, Rm 650–850 MPa | Maximum-toughness condition for thick turbine castings/forgings and sour or low-temperature service. | 520 | 730 | 22 | 19 HRC | — |
Solution annealed | Softest supply condition for heavy machining or cold work before final quench-and-temper. | 550 | 720 | 22 | 17 HRC | — |
ASTM A487 Gr. CA6NM Class A, normalized and tempered casting | Cast counterpart used for hydro turbine runners and pump casings; same metallurgy, slightly lower minimum strength and ductility than wrought. | 690 | 830 | 18 | 24 HRC | — |
QT780Default Quenched and double tempered, Rm 780–980 MPa | Standard commercial condition: best balance of 620 MPa yield, high CVN and weldability — pick this unless a spec says otherwise. | 700 | 850 | 18 | 25 HRC | — |
Cold drawn | Small-diameter bar with tight tolerance and bright finish; slightly higher yield, lower ductility than QT780. | 780 | 900 | 14 | 29 HRC | 2.9 % IACS |
As-welded deposit | Untempered fresh martensite in weld/HAZ — hard and low toughness; post-weld temper at 580–620 °C is normally required. | 800 | 1,000 | 12 | 38 HRC | 2.9 % IACS |
Quenched and tempered, Rm 900–1100 MPa | Highest-strength standard condition for shafts and highly loaded parts where toughness and NACE hardness limits are less critical. | 870 | 980 | 15 | 31 HRC | — |
What is 415?
415 is a low-carbon Ni-Mo "soft martensitic" stainless (UNS S41500), the wrought counterpart to cast CA6NM of ASTM A487, combining high toughness with good weldability. Engineers specify it for hydro turbine runners, pump shafts and heavy valve bodies in forged bar, plate and cast form; the quenched-and-tempered default is about 700 MPa yield, 850 MPa tensile, 18 % elongation and 260 HB (25 HRC), with service to 450 °C. Machinability is low (score 40) and the tempering window must avoid 450–550 °C embrittlement; use 410 or 414 where weldability is less critical and cost matters. 415 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,400°C (2,552 °F). 415 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 92% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi).
What is 415 used for?
- hydro turbine runners
- pump shafts
- valve bodies
- compressor parts
Advantages
- Conducts heat well — 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades
- High strength — 700 MPa (102 ksi), better than 92% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
Limitations
- Limited ductility — 18%, worse than 83% of stainless steel grades
- Needs corrosion protection — 48/100, worse than 80% of stainless steel grades
415 properties
Typical room-temperature values for 415-QT780; bars are the position among stainless steel grades.
Physical3
415 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
415 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 92% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
415 is rated for continuous service to 450°C (842 °F). It conducts heat at 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
415 conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 80% of stainless steel grades.
Sustainability4
Producing a kilogram of 415 takes about 53 MJ of energy and emits 4.5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 50%.
Manufacturability8
415's machinability is fair (40/100, better than 72% of stainless steel grades); weldability very good (72/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 415 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 415
Is 415 easy to machine?
Machines like a 28 HRC alloy steel — rigid setups, sharp positive-rake carbide, moderate speed and heavy feed to avoid work-hardened glaze; rough in the annealed condition when possible.
Can 415 be welded?
Best-welding martensitic stainless: use matching 410NiMo filler, preheat 100–150 °C on heavy sections, keep interpass <150 °C and post-weld temper 580–620 °C (never 450–550 °C).
Can 415 be formed, bent or molded?
Hot work at 1150–950 °C then air cool and temper; cold forming is limited to gentle bending with generous radii — final quench 950–1050 °C + double temper is preferred.
415 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 |
|---|---|---|
| Clow carbon gives soft, tough lath martensite | ≤ 0.05 | 0.03 |
| Si | ≤ 0.6 | 0.3 |
| Mn | 0.5 – 1 | 0.75 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 11.5 – 14 | 12.75 |
| Ni | 3.5 – 5.5 | 4.5 |
| Mo | 0.5 – 1 | 0.7 |
| Nlimited in some product specs / EN 1.4313 | ≤ 0.03 | 0.02 |
| Fe | balance |
What surface finishes work on 415?
Passivate per ASTM A967 or electropolish after machining; takes a good mirror polish, and hard-chrome or thermal-spray overlays are common on turbine and shaft wear surfaces.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 415 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S41500
- ASTM
- A487 Gr CA6NM
How much does 415 cost?
415 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
415 — frequently asked
What is 415 used for?
415 is typically used for hydro turbine runners, pump shafts, valve bodies and compressor parts. In short: best-welding martensitic stainless; wrought CA6NM equivalent; tough at 700 MPa yield.
What is the yield strength of 415?
415 has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 92% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 415 easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Machines like a 28 HRC alloy steel — rigid setups, sharp positive-rake carbide, moderate speed and heavy feed to avoid work-hardened glaze; rough in the annealed condition when possible.
Can 415 be welded?
Yes — weldability is rated very good (72/100). Best-welding martensitic stainless: use matching 410NiMo filler, preheat 100–150 °C on heavy sections, keep interpass <150 °C and post-weld temper 580–620 °C (never 450–550 °C).
What surface finishes work on 415?
Passivate per ASTM A967 or electropolish after machining; takes a good mirror polish, and hard-chrome or thermal-spray overlays are common on turbine and shaft wear surfaces.
Can 415 be formed, bent or molded?
Hot work at 1150–950 °C then air cool and temper; cold forming is limited to gentle bending with generous radii — final quench 950–1050 °C + double temper is preferred.
What is the maximum service temperature of 415?
415 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 415-QT780 and 415-QT650?
QT780 is the default condition — standard commercial condition: best balance of 620 MPa yield, high CVN and weldability — pick this unless a spec says otherwise. QT650: maximum-toughness condition for thick turbine castings/forgings and sour or low-temperature service. Yield strength is 700 MPa in QT780 versus 520 MPa in QT650.
How much does 415 cost?
415 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip (UNS S41500) — ASTM International (2023)
- ASTM A182/A182M — Forged or Rolled Alloy and Stainless Steel Pipe Flanges and Fittings (Grade F6NM) — ASTM International (2022)
- ASTM A487/A487M — Steel Castings Suitable for Pressure Service (Grade CA6NM) — ASTM International (2020)
- EN 10088-3 — Stainless steels, Part 3: Semi-finished products, bars, rods (X3CrNiMo13-4, 1.4313) — CEN (2014)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Soft martensitic stainless 1.4313 / S41500 datasheet — Böhler / Sandvik / Outokumpu (2022)
- GB/T 1220 ZG06Cr13Ni4Mo (2007)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.