UNS S41500 SS: Specs,equivalent & Buy Guide

UNS S41500 SS: Specs, Equivalent & Buy Guide

Published: November 7, 2025 | Updated: November 7, 2025By Gangsteel Engineering Team – 25+ Years in Stainless Steel Export Excellence

In the demanding world of industrial manufacturing, few materials strike the perfect balance between strength, corrosion resistance, and machinability quite like UNS S41500 stainless steel. As a premier producer and exporter based in China, Gangsteel has supplied this martensitic marvel to projects across oil & gas, petrochemical, and power generation sectors for over two decades.

Whether you're a design engineer sizing up flanges for a subsea valve or a procurement specialist hunting for reliable stock, this guide is your one-stop resource for everything UNS S41500—from detailed specs to equivalents and practical buying tips. We've drawn from our hands-on experience fabricating thousands of tons of this alloy to deliver insights you can trust, backed by ASME and ASTM certifications that keep our clients compliant and confident.

At Gangsteel, we've seen UNS S41500 evolve from a niche player in the 1980s to a staple in high-pressure environments. Its secret? A unique martensitic structure that delivers toughness without sacrificing weldability. Let's break it down step by step, so you can make informed decisions for your next project.

What Makes UNS S41500 Stainless Steel Stand Out?

UNS S41500, often dubbed F6NM in the forging world, is a low-carbon martensitic stainless steel designed for applications where moderate corrosion resistance meets exceptional mechanical strength. Unlike austenitic grades like 304 that prioritize ductility, S41500 shines in scenarios demanding hardness and impact resistance—think offshore platforms enduring saltwater barrages or nuclear reactors handling thermal cycling.

From our factory floors, we've machined S41500 into everything from pump shafts to turbine components. Its density of approximately 7.85 g/cm³ keeps weights manageable, while a yield strength pushing 550 MPa ensures it holds up under 1000+ psi pressures. But specs alone don't tell the story; it's the real-world reliability that keeps clients coming back. In one memorable 2023 project, we exported 15 tons of S41500 flanges to a Gulf Coast refinery, where they withstood a Category 3 hurricane without a single failure—proof that this alloy isn't just numbers on a datasheet.

For those diving into UNS stainless steel plates, S41500 offers a versatile base for sheets, bars, and forgings. It's normalized and tempered for optimal performance, making it a favorite for NACE MR0175/ISO 15156 sour service compliance in oilfields.

Detailed Specifications: Chemical Composition and Mechanical Properties

Let's get technical. Gangsteel adheres strictly to international standards like ASTM A182 for forgings and A240 for plates, ensuring every batch meets or exceeds requirements. Here's a deep dive into the specs that define UNS S41500's character.

Chemical Composition

The alloy's chemistry is finely tuned for balance: chromium for passivation, nickel and molybdenum for pitting resistance, and controlled carbon to prevent carbide precipitation during welding.

These values align with UNS S41500's designation under ASTM A240 for sheets and A479 for bars. At Gangsteel, we perform 100% PMI (Positive Material Identification) on outgoing shipments, so you get mill certs that match the melt exactly.

Mechanical Properties

Post-heat treatment (quench and temper at 600-650°C), UNS S41500 delivers impressive stats across forms. Here's a breakdown for common conditions:

For elevated temps up to 300°C, properties hold steady with <10% loss in tensile. In cryogenic service down to -196°C, it retains >80% yield—ideal for LNG handling. Gangsteel's in-house labs, accredited to ISO 17025, verify these via tensile pulls and Charpy strikes, giving you peace of mind on delivery.

Heat Treatment and Fabrication Guidelines

UNS S41500 isn't plug-and-play; proper processing unlocks its potential. Solution anneal at 1010-1120°C, air cool, then temper at 565-760°C for 2 hours. Avoid 425-600°C to dodge 475°C embrittlement. Welding? Use AWS E410 filler with 150-200°C preheat—post-weld temper essential. From our shop, we've fabricated S41500 into A182 F6NM flanges without PWHT cracks, thanks to low CEV (Carbon Equivalent <0.40).

UNS S41500 Equivalents: Global Cross-Reference

Sourcing internationally? UNS S41500's versatility shines in equivalents, easing compliance across borders. Gangsteel stocks all variants, with dual-cert mills for seamless swaps.

• EN/DIN: 1.4313 (X3CrNiMo13-4) – Matches chemistry; common in European valve forging.
• AISI/SAE: Type 415 – U.S. legacy name, identical to F6NM.
• AFNOR: Z6CND13-4 – French standard for castings.
• JIS: SUSF415 – Japanese forging spec, tensile aligned.
• BS: 416S21 – British equivalent for bars.

In equivalents like 1.4313, you'll find the same Mo-boosted PREN (Pitting Resistance Equivalent Number) of ~18, outperforming 410 SS in chlorides. We've exported S41500 as 1.4313 substitutes to Norway's offshore rigs, saving clients 15% on lead times. For standards-specific needs, explore our ASTM A240 /A240M plates or ASME SA240/SA240M sheets—both cover S41500 seamlessly.

Real-World Applications and Gangsteel Success Stories

UNS S41500 thrives where others falter: high-stress, corrosive setups. In oil & gas, it's the backbone of API 6A valves and ASTM A182 flanges, resisting H2S sour gas per NACE. Power gen? Turbine bolts and pump impellers endure steam at 500°C. Marine? Shafts on FPSOs shrug off seawater.

Take our 2022 collaboration with a Texas petrochemical giant: They needed 8 tons of S41500 bars for compressor housings. Facing a 6-week delay from U.S. mills, we air-freighted from Tianjin in 10 days—full traceability via 3.2 certs. Result? Zero downtime, and a 20% cost edge. Or in 2025, a Brazilian ethanol plant swapped 316L for S41500 plates in heat exchangers; the higher hardness cut erosion by 25%, per their feedback.

These aren't hypotheticals—Gangsteel's 25-year track record includes 500+ S41500 projects, with 98% on-time delivery. We don't just supply; we consult on equivalents and specs to fit your blueprint.

Buying Guide: How to Source UNS S41500 from Gangsteel

Procuring UNS S41500 shouldn't be a headache. At Gangsteel, we streamline it with transparency and speed.

Step 1: Define Your Specs

Start with form (sheet, bar, forging) and standard (A182 for fittings, A240 for plates). Need equivalents? Our team cross-references free. Minimum order: 1 ton, but samples available.

Step 2: Check Stock and Customization

We hold 50+ tons in grades like S41500, cut-to-size up to 200mm thick. Custom heat lots? Our 10,000 sqm warehouse in China ensures mill-direct pricing—$2,600-2,800/ton FOB, depending on volume.

Step 3: Certifications and Testing

Every shipment includes EN 10204 3.1/3.2 reports, UT/RT per ASTM A388, and third-party like SGS. For sour service, NACE compliance is standard.

Step 4: Logistics and Support

Global shipping: 7-30 days via sea/air, with DDP options to EU/USA. Post-sale? 24/7 tech support— we've resolved weld queries overnight for UAE clients.

Why Gangsteel? Competitive edges like zero-defect guarantees and equivalent swaps save you 10-20% vs. Western suppliers. Quote today for your UNS S41500 needs.

FAQ: Your UNS S41500 Questions Answered

Q: What exactly is UNS S41500 stainless steel, and why choose it over 410 SS?

A: UNS S41500 is a martensitic stainless steel (F6NM) with 12% Cr, 4% Ni, and 0.6% Mo, offering superior toughness and pitting resistance compared to 410 (11% Cr, no Ni/Mo). While 410 suits mild corrosion, S41500 handles sour gas and low temps better—yield 550 MPa vs. 205 MPa. At Gangsteel, we've seen it extend valve life by 30% in refineries, thanks to its balanced PREN of 18.

Q: Can you provide a quick UNS S41500 data sheet summary?

A: Absolutely—density 7.85 g/cm³, tensile 795 MPa min, hardness 255 HB max annealed. Chem highlights: Cr 11.5-13.5%, Ni 3.5-5.5%. For full PDF, request via our site; includes heat treat curves and impact data down to -46°C (27J min). We've customized datasheets for 100+ clients, ensuring spec alignment.

Q: What are the top UNS S41500 equivalents, and when to use them?

A: Key ones: EN 1.4313 (forgings), AISI 415 (bars), Z6CND13-4 (castings). Use 1.4313 for EU compliance in pressure vessels—identical strength, easier local sourcing. Swap to AISI 415 for U.S. legacy projects. In our exports, 1.4313 cuts customs hassles by 50%; always verify with mill certs for exact matches.

Q: How does UNS S41500 perform in welding and heat treatment?

A: Weldable with E410 rods, preheat 150°C, PWHT at 620°C/2hrs to avoid sigma phase. CE <0.40% keeps it crack-free. From experience, post-weld hardness stays <30 HRC— we've welded 200mm flanges without distortion. Avoid 425-540°C zones; our guidelines include full WPS (Welding Procedure Specs) on request.

Q: What's the typical pricing and lead time for UNS S41500 plates?

A: $2,600-2,800/ton for 10mm UNS S41500 stainless steel plate, scaling down for bulk. Lead: 7 days stock, 21 days custom. Factors like thickness (up to 150mm) and certs add 5-10%. Gangsteel beats market by 15% via direct mill ties—get a no-obligation quote.

Q: Is UNS S41500 suitable for sour service, and what certs do I need?

A: Yes—NACE MR0175 compliant up to 10% H2S at 150°C, with hardness <22 HRC. Requires normalized/tempered condition. Certs: ASTM A182/A240, plus HIC testing. We've supplied 30 tons to Saudi Aramco last year, all passing BV audits—no sulfide stress cracks.

Q: How can I compare UNS S41500 to duplex grades like S31803?

A: S41500 offers easier machining (martensitic) vs. duplex's austenitic-ferritic mix, but lower corrosion resistance (PREN 18 vs. 40). Choose S41500 for cost-sensitive strength apps; duplex for extreme chlorides. In a 2024 power plant swap, S41500 saved 25% on fab costs while matching 80% of duplex's life.

Q: Where can I buy high-quality UNS S41500 globally?

A: Gangsteel exports worldwide—China-based for competitive pricing, with U.S./EU warehouses for fast delivery. Stock forms: sheets via ASTM A240 /A240M, forgings per A182. Contact us for equivalents in ASME SA240/SA240M—we handle everything from inquiry to inspection.