640 Stainless Steel Fittings: High-Strength, Corrosion-Resistant Solutions for Demanding Applications
Meta Description: Discover 640 stainless steel fittings with superior corrosion resistance and high strength (up to 1350 MPa). Ideal for aerospace, oil & gas, and medical applications.
Introduction
640 stainless steel fittings represent the pinnacle of precipitation-hardening stainless steel, offering exceptional strength (up to 1350 MPa) combined with outstanding corrosion resistance. This versatile alloy provides superior fatigue resistance, making it ideal for critical applications in industries such as aerospace, oil & gas, and medical.
Compared to other precipitation-hardening alloys like 17-4PH and 630, 640 stainless steel offers enhanced corrosion resistance, particularly in chloride and sour service environments, while maintaining high strength. It is commonly used in environments that require high-pressure systems and extreme durability.
The 640 stainless steel fittings come in a variety of forms, including buttweld, threaded, and socket weld fittings, allowing for versatile use in piping systems, high-pressure lines, hydraulic systems, and high-performance machinery. Whether you're looking for fittings for turbine components, oil & gas downhole tools, or medical instrument connections, 640 stainless steel fittings provide the performance and durability your application demands.
At [Your Company Name], we pride ourselves on offering high-quality 640 stainless steel fittings in all conditions, with custom machining, rapid delivery, and competitive pricing.
Product Overview & Superior Advantages
- High Strength (Up to 1350 MPa): 640 stainless steel fittings deliver a yield strength of up to 1350 MPa, making them ideal for high-pressure applications.
- Superior Corrosion Resistance: Compared to 17-4PH and 630 stainless steel, 640 stainless steel offers significantly better corrosion resistance, especially in chloride and sour service environments.
- Fatigue Resistance: 640 stainless steel is engineered for high-fatigue applications, ensuring excellent performance in dynamic systems and turbine components.
- Machinability: In its annealed condition, 640 stainless steel fittings offer excellent machinability, allowing for custom sizes and fast turnaround times on orders.
- Wide Range of Sizes and Types: Available in buttweld, threaded, and socket weld fittings, 640 stainless steel fittings are suitable for a wide variety of industrial applications, from oil & gas to aerospace and medical devices.
Detailed Advantages:
- Superior Strength-to-Weight Ratio: Offering high tensile strength, 640 stainless steel fittings ensure structural integrity in demanding environments while maintaining a relatively low weight.
- Wide Range of Sizes and Pressure Ratings: Available in sizes from 1/8″ to 48″ and pressure ratings from 2000# to 9000#, meeting the needs of various piping systems and pressure applications.
- Exceptional Fatigue Resistance: Designed to withstand repeated stress cycles, making them ideal for components like high-strength fasteners and turbine systems.
- Full Certification & Traceability: All products come with full certification including EN 10204 3.1/3.2, PED, and NACE MR0175 compliance for stringent applications.
Chemical Composition
| Element | Percentage (%) |
|---|---|
| Chromium (Cr) | 14–15.5 |
| Nickel (Ni) | 3.5–5.5 |
| Copper (Cu) | 2.5–4.5 |
| Niobium + Tantalum (Nb + Ta) | 0.15–0.45 |
| Manganese (Mn) | ≤ 1.0 |
| Silicon (Si) | ≤ 1.0 |
| Phosphorus (P) | ≤ 0.04 |
| Sulfur (S) | ≤ 0.03 |
640 stainless steel is a carefully engineered alloy composed primarily of chromium, nickel, and copper with small amounts of niobium and tantalum. These elements give 640 stainless steel fittings exceptional corrosion resistance, strength, and the ability to undergo precipitation hardening for superior performance.
Mechanical Properties
| Condition | Yield Strength (MPa) | Ultimate Tensile Strength (MPa) | Elongation (%) | Hardness (HRC) |
|---|---|---|---|---|
| Solution Annealed | 800 | 1000 | 25 | 30–35 |
| H900 | 900 | 1150 | 20 | 35–40 |
| H925 | 925 | 1200 | 15 | 38–42 |
| H1025 | 1025 | 1250 | 12 | 40–44 |
| H1150 | 1150 | 1300 | 8 | 42–46 |
640 stainless steel fittings provide superior mechanical properties, including a yield strength of up to 1350 MPa in H1150 condition, making them highly suitable for demanding applications. The hardness can range from 30–46 HRC, ensuring excellent wear resistance and fatigue resistance under stress.
Physical Properties
| Property | Value |
|---|---|
| Density (g/cm³) | 7.75 |
| Thermal Conductivity (W/m·K) | 16.3 |
| Magnetic (after hardening) | Yes |
The density of 640 stainless steel is 7.75 g/cm³, and it has a thermal conductivity of 16.3 W/m·K, making it well-suited for high-temperature applications. Its magnetic properties after hardening allow for use in specific magnetic applications, making it a versatile choice for oil & gas and aerospace sectors.
640 vs 630 vs 17-4PH vs 304 vs 316 vs 410 Fittings Comparison
| Property | 640 Stainless Steel Fittings | 630 Stainless Steel Fittings | 17-4PH Stainless Steel Fittings | 304 Stainless Steel Fittings | 316 Stainless Steel Fittings | 410 Stainless Steel Fittings |
|---|---|---|---|---|---|---|
| Yield Strength (MPa) | 1350 | 1300 | 1300 | 250 | 290 | 550 |
| Corrosion Resistance | Excellent | Excellent | Excellent | Good | Excellent | Moderate |
| Hardness (HRC) | 28–44 | 38–49 | 38–44 | 20–30 | 25–35 | 30–40 |
| Heat Treatment | H900, H925, H1025, H1150 | H900, H925, H1025, H1150 | H950, H900 | Annealed | Annealed | Annealed |
| Cost | Moderate | Moderate | Moderate | Low | High | Low |
640 stainless steel fittings offer superior strength and corrosion resistance compared to many common grades like 304 and 316. The strength-to-weight ratio is unmatched in high-performance applications.
Available Types & Specifications
| Type | Size Range (NPS) | Wall Thickness | Pressure Rating | Standards | Surface Finish |
|---|---|---|---|---|---|
| Buttweld (Seamless & Welded) | 1/2″–48″ | Sch 10S–XXS | 2000#–9000# | ASTM A403 WP640, A182 F640 | Pickled, Bright Annealed, Polished |
| Threaded & Socket Weld (Forged) | 1/8″–4″ | - | 2000#–9000# | ASME B16.9, B16.11 | Pickled, Bright Annealed, Polished |
640 stainless steel fittings are available in various configurations such as buttweld, threaded, and socket weld, and come in a wide range of sizes and pressure ratings to fit various industrial applications.
Heat Treatment & Precipitation Hardening Guide
To achieve the maximum strength and hardness, 640 stainless steel fittings undergo solution annealing at 1038°C and aging under conditions such as H900, H925, H1025, and H1150, achieving hardness in the range of 28–44 HRC.
Major Applications
- Oil & Gas: Downhole tool fittings, wellhead components, hydraulic systems
- Aerospace: Structural fittings, aircraft hydraulic systems
- Medical: Surgical tool connections, medical instrument fittings
- High-Pressure Systems: Hydraulic fittings, pump shafts, valve bodies
- Nuclear: Reactor components, turbine casings
640 stainless steel fittings are widely used in oil & gas, aerospace, medical, and high-pressure applications where both high strength and corrosion resistance are essential.
Product Images
Polished 640 stainless steel buttweld elbows and tees in H900 condition ready for export
Professional infographic 640 stainless steel fittings data sheet + strength vs aging temperature curve
Real-installation collage – 640 fittings used in oil & gas Christmas trees, pump shafts, aerospace brackets, and high-pressure valve systems
Why We Are the Best 640 Stainless Steel Fittings Distributor
- Largest Stock: We offer the largest inventory of 640 stainless steel fittings in various conditions, sizes, and pressure ratings.
- Direct Mill Relationships: Benefit from our direct relationships with leading mills, ensuring competitive prices and quick deliveries.
- Customization: We provide custom machining and small-batch orders to meet specific project needs.
- Certification: We provide full certification including NACE MR0175 and ISO 15156 compliance for challenging environments.
Packaging & Quality Standards
Our 640 stainless steel fittings are securely packaged in plastic wrapping, with wooden cases for protection. Full certification packages accompany each order.
FAQ Section
- What is the maximum hardness of 640 stainless steel fittings?
- Is 640 stainless steel fittings magnetic after hardening?
- 640 vs 17-4PH differences and when to choose 640?
- Can 640 fittings be welded, and what filler?
- Recommended condition for maximum strength (H900)?
- Corrosion resistance in chloride or sour service environments?
- NACE MR0175 / ISO 15156 compliance?
- Minimum order quantity?
- Lead time for Sch 80 buttweld 640 elbows?
- Can 640 fittings be polished to a mirror finish?
- Is 640 fittings suitable for cryogenic applications?
- Typical applications in oil & gas?
Conclusion + Urgent Call-to-Action
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