Stainless Steel S41425
UNS S41425
S41425 is a supermartensitic 13Cr-5Ni-2Mo stainless with very low carbon, sitting between conventional 13Cr and duplex grades for sour service.
Reference datasheet — S41425 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 HT condition
S41425 tempers and conditions
S41425 is supplied in 5 conditions, soft to hard. HT is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softened delivery condition for machining, forming or as an intermediate before final Q&T. | 570 | 760 | 24 | 22 HRC | — |
Quenched and tempered | Lower-strength Q&T condition with maximum toughness and the widest sour-service envelope (hardness held ≤ 28 HRC). | 690 | 850 | 19 | 25 HRC | 2.5 % IACS |
HTDefault Quenched and double tempered | Standard high-strength delivery condition for downhole tubulars, wellhead and valve parts requiring 95 ksi class yield with ≤ 32 HRC. | 810 | 930 | 17 | 29 HRC | 2.5 % IACS |
quenched and tempered to 110 ksi (758 MPa) minimum yield | Higher-strength oilfield tubular grade (super 13Cr 110) for deeper wells; sour-service window is narrower than the 95 ksi class. | 810 | 950 | 18 | 32 HRC | — |
quenched and tempered to 125 ksi (862 MPa) minimum yield | Maximum-strength condition offered for sweet high-pressure wells; not qualified for most sour environments because hardness exceeds typical MR0175 caps. | 900 | 1,030 | 16 | 35 HRC | — |
What is S41425?
S41425 is a supermartensitic 13Cr-5Ni-2Mo stainless with very low carbon, sitting between conventional 13Cr and duplex grades for sour service. Oilfield users specify it in the quenched-and-tempered condition for tubulars and downhole hardware, with default values of 810 MPa yield, 930 MPa tensile, 17% elongation and 285 HB (29 HRC) at 7.75 g/cm³ and 200 GPa modulus. Limits are 480 °C maximum service, moderate general corrosion resistance (score 44), low thermal conductivity of 25 W/m·K and poor cold formability. S41500 (F6NM) is the nearest lower-strength alternative. S41425 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). S41425 has a yield strength of 810 MPa (117 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 97% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 200 GPa (29 Msi).
What is S41425 used for?
- Oil country tubular goods (OCTG)
- Downhole tools
- Sour-service wellhead components
- High-strength oilfield fasteners
Advantages
- High strength — 810 MPa (117 ksi), better than 97% of stainless steel grades
- Conducts heat well — 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades
- Low embodied carbon — 3.4 kg CO₂/kg, better than 91% of stainless steel grades
Limitations
- Needs corrosion protection — 44/100, worse than 88% of stainless steel grades
- Limited ductility — 17%, worse than 86% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
S41425 properties
Typical room-temperature values for S41425-HT; bars are the position among stainless steel grades.
Physical3
S41425 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
S41425 has a yield strength of 810 MPa (117 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 97% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S41425 is rated for continuous service to 480°C (896 °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 10.8 µm/m·K (6 µin/in·°F).
Electrical3
S41425 conducts electricity at 2.5 % IACS, better than 75% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (44/100), worse than 88% of stainless steel grades.
Sustainability4
Producing a kilogram of S41425 takes about 53 MJ of energy and emits 3.4 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
S41425's machinability is fair (35/100, better than 51% of stainless steel grades); weldability good (65/100); formability poor (25/100).
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. S41425 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S41425
Is S41425 easy to machine?
Machine in the tempered condition with rigid setups, sharp carbide tooling, low speed / heavy feed and flood coolant; the gummy low-carbon martensite work-hardens and rubs if feeds are too light.
Can S41425 be welded?
Readily weldable (GTAW/GMAW) with low heat input and matching supermartensitic or superduplex/Ni-base filler; a post-weld temper at about 600–650 °C restores HAZ toughness and keeps hardness under NACE limits.
Can S41425 be formed, bent or molded?
Hot forge/ring-roll at roughly 1150–900 °C followed by full austenitise-quench-temper; cold forming is limited to mild bending due to the high yield strength.
S41425 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 |
|---|---|---|
| Cultra-low carbon for weldability and SSC resistance | ≤ 0.05 | 0.02 |
| Mn | 0.5 – 1 | 0.7 |
| Si | ≤ 0.5 | 0.25 |
| P | ≤ 0.02 | 0.01 |
| Slow S for sour service | ≤ 0.01 | 0 |
| Cr | 11.5 – 13.5 | 12.5 |
| Ni | 4 – 6 | 5 |
| Mo | 1.5 – 2.5 | 2 |
| Cu | ≤ 0.3 | 0.1 |
| Naustenite stabiliser / strengthener | 0.01 – 0.1 | 0.05 |
| Fe | balance |
What surface finishes work on S41425?
Passivate or electropolish per ASTM A967 after machining; the fine martensitic structure takes a good mechanical polish, and shot peening or nitriding can be added for 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 S41425 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- 13-5-2
- Similar grades
- S41500
How much does S41425 cost?
S41425 is a high-cost stainless steel ($$$$), pricier than about 78% 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.
S41425 — frequently asked
What is S41425 used for?
S41425 is typically used for oil country tubular goods (OCTG), downhole tools, sour-service wellhead components and high-strength oilfield fasteners. In short: weldable high-strength 13Cr; sour-service martensitic grade; stronger than S41500.
What is the yield strength of S41425?
S41425 has a typical yield strength of 810 MPa (117 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 97% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is S41425 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Machine in the tempered condition with rigid setups, sharp carbide tooling, low speed / heavy feed and flood coolant; the gummy low-carbon martensite work-hardens and rubs if feeds are too light.
Can S41425 be welded?
Yes — weldability is rated good (65/100). Readily weldable (GTAW/GMAW) with low heat input and matching supermartensitic or superduplex/Ni-base filler; a post-weld temper at about 600–650 °C restores HAZ toughness and keeps hardness under NACE limits.
What surface finishes work on S41425?
Passivate or electropolish per ASTM A967 after machining; the fine martensitic structure takes a good mechanical polish, and shot peening or nitriding can be added for wear surfaces.
Can S41425 be formed, bent or molded?
Hot forge/ring-roll at roughly 1150–900 °C followed by full austenitise-quench-temper; cold forming is limited to mild bending due to the high yield strength.
What is the maximum service temperature of S41425?
S41425 is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S41425-HT and S41425-A?
HT is the default condition — standard high-strength delivery condition for downhole tubulars, wellhead and valve parts requiring 95 ksi class yield with ≤ 32 HRC. A: softened delivery condition for machining, forming or as an intermediate before final Q&T. Yield strength is 810 MPa in HT versus 570 MPa in A.
How much does S41425 cost?
S41425 is a high-cost stainless steel ($$$$), pricier than about 78% 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 A479/A479M — Stainless Steel Bars and Shapes for Pressure Vessels — ASTM (2023)
- ASTM A276/A276M — Stainless Steel Bars and Shapes — ASTM (2017)
- ANSI/NACE MR0175 / ISO 15156-3 — Cracking-resistant CRAs for H2S-containing environments — NACE/ISO (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Super 13Cr martensitic stainless OCTG datasheets (13Cr-5Ni-2Mo) — Nippon Steel / JFE / Vallourec (2021)
- GB/T 1220 / SY/T oilfield tubular material specifications — SAC / NEA China (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.