Magnadur 501 Non-Magnetic Steel

Overview of Magnadur 501 Non-Magnetic Steel

Magnadur 501 is a specialized non-magnetic stainless steel originally developed by Deutsche Edelstahlwerke GmbH (DEW). Classified as a high-nitrogen austenitic specialty alloy, it is engineered for extreme operational demands in the oil and gas sector. Its core chemical matrix features high manganese (18.5-22.0%), substantial chromium (19.0-22.0%), and strategic nitrogen (0.32-0.40%) additions. This yields a robust structural profile without relying on excessive nickel content.

The defining characteristic of Magnadur 501 is its strict magnetic permeability of μ < 1.01, ensuring absolute magnetic neutrality for sensitive downhole instrumentation. This property is seamlessly paired with a minimum yield strength of 770-825 MPa and superior resistance to pitting and stress corrosion cracking in sour service environments. Its PREN ranges from 19 to 23, guaranteeing robust localized corrosion defense.

For directional drilling and measurement sectors where magnetic interference jeopardizes operational accuracy, Magnadur 501 provides a verified, high-strength solution. As a premier supplier of non-magnetic steel, ShunFu Metal ensures that procurement teams receive mill-certified materials tailored for the most demanding downhole conditions.

Equivalent Grades and Classification

As a proprietary specialty steel, Magnadur 501 does not have direct equivalent grades under general ASTM, EN, or JIS systems. Its unique high-nitrogen, low-nickel austenitic matrix is exclusively manufactured under DEW specifications. This specialization ensures consistent performance but requires sourcing from certified stockholders like ShunFu Metal to guarantee authentic metallurgical properties.

Key Applications of Magnadur 501

Magnadur 501 is purpose-built for downhole environments where both magnetic transparency and mechanical strength are non-negotiable. It is the preferred material for measurement-while-drilling (MWD) and logging-while-drilling (LWD) systems, ensuring that directional sensors operate without magnetic distortion.

• MWD sensor housings and critical electronic components
• Non-magnetic drill collar (NMDC) bodies for directional drilling assemblies
• LWD tool enclosures and pressure housings
• Directional drilling stabilizers and mandrels
• Standard drill collar components requiring pitting corrosion resistance
• Petroleum measurement instruments operating in magnetic field environments
• Downhole tool components in sour gas (H2S) service conditions
• Mining exploration drilling sensors and non-magnetic subs

By integrating Magnadur 501 into your bottom-hole assembly (BHA), you mitigate magnetic interference risks while maintaining the structural integrity required for deep-well drill pipe operations.

Specifications and Compliance Standards

Being a proprietary special steel, Magnadur 501 is manufactured strictly under Deutsche Edelstahlwerke GmbH specifications. It does not carry a universal designation under ASTM, AMS, DIN, EN, ISO, JIS, GOST, or GB grade systems. However, its performance compliance is rigorously verified against critical testing and application standards.

• ASTM A262 Practice A and E: Standard for detecting intergranular corrosion in austenitic stainless steels, applicable to bars and hollow bars.
• PREN Value Standard: Pitting Resistance Equivalent Number assessment (PREN 19-23), calculated via the formula (%Cr + 3.3x %Mo + 16x %N).

Available Sizes and Delivery Options

ShunFu Metal provides Magnadur 501 across comprehensive dimensional ranges to accommodate diverse downhole requirements. Our inventory and production flexibility ensure that both standard and custom dimensions are fulfilled efficiently.

• Forged Round Bars: Diameter 20 mm to 300 mm (0.8" to 12")
• Forged Hollow Bars: Outer diameter 50 mm to 280 mm (2" to 11") with customizable wall thicknesses
• Rolled Round Bars & Flat Bars: Available upon request for specific project dimensions

Our production capacity is supported by API-standard regularly calibrated heat treatment furnaces, ensuring precise mechanical property attainment. For precision geometry, we utilize BTA deep hole drilling, CNC lathes and milling machines, and long-distance gunhole drilling to deliver tight-tolerance hollow bars.

Ready Stock (Common sizes)

Single-piece purchase available; delivery within approximately 7 days.

Custom Forged/Rolled Bars

MOQ typically 3 tons; delivery within approximately 30 days.

Small Batch Special Grades

Melted via our small induction furnace (3-5 tons MOQ).

Large Volume Orders

Fast delivery via 30-60 ton EAF operations.

Chemical Composition of Magnadur 501

The high-nitrogen, high-manganese composition of Magnadur 501 eliminates the need for expensive nickel additions while maintaining a fully austenitic, non-magnetic structure at all temperatures. The precise elemental balance ensures both high strength and excellent corrosion resistance.

Melting and Processing Routes

As a high-nitrogen non-magnetic stainless steel, Magnadur 501 requires precise melting control to retain nitrogen and prevent segregation. ShunFu Metal offers flexible melting routes tailored to your application severity, ensuring cost-effectiveness without compromising performance.

Conventional Route (EAF + AOD + LF + VD)

Suitable for standard oil and gas requirements, providing reliable mechanical and chemical consistency.

Elevated Cleanliness Route (ESR or PESR)

Recommended for reduced segregation and enhanced microstructural homogeneity in demanding downhole conditions.

Ultra-Pure Route (VIM + VAR)

Reserved for the most critical sour-service or MWD applications requiring supreme material cleanliness.

We encourage clients to consult with our technical team to select the most performance-appropriate melting protocol for their specific corrosion-resistant alloy needs.

Mechanical Properties at Room Temperature

Magnadur 501 achieves its high mechanical strength through forging and work-hardening (strain hardening) rather than traditional quenching and tempering. This guarantees that the non-magnetic permeability is permanently retained throughout the component's lifecycle. The following data applies to forged and work-hardened conditions.

Note: Low-temperature and high-temperature mechanical property data are not documented in the proprietary specifications and are therefore omitted to prevent inaccuracies in engineering calculations.

Heat Treatment and Strengthening Mechanisms

Unlike conventional steels that rely on quenching and tempering, high-nitrogen non-magnetic stainless steels like Magnadur 501 achieve their high yield strength through forging and strain hardening. This work-hardening process locks in the mechanical strength while permanently maintaining the essential non-magnetic permeability required for directional drilling sensors.

Conventional quenching and tempering hold times are omitted as they are not applicable to the work-hardened strength mechanism of this specific high-nitrogen alloy. Specific thermal processing parameters remain proprietary to the DEW specification.

Surface Finish and Precision Machining

ShunFu Metal provides comprehensive surface and precision machining solutions for Magnadur 501 downhole components. Our advanced capabilities ensure that both internal and external geometries meet the strict tolerances required for measurement tools and pressure housings.

• Internal Finishing: BTA deep hole boring and long-distance gunhole drilling achieve precise internal geometries for hollow bars and drill collars.
• External Finishing: Turning, milling, and CNC machining achieve dimensional tolerances down to ±0.05 mm.
• Fatigue Enhancement: Roller burnishing and shot peening improve surface hardness and induce beneficial compressive residual stress, achieving internal surface roughness of Ra ≤ 0.4 μm.

Standard forged bars are supplied in peeled or turned conditions (Ra ≤ 3.2 μm), while ground finishes (Ra ≤ 0.8 μm) are available for precision measurement tool requirements where surface integrity is critical.

Quality Assurance and Inspection Protocols

Quality assurance at ShunFu Metal spans the entire production lifecycle, ensuring full traceability and compliance for Magnadur 501 products. Pre-production involves rigorous incoming material verification. During processing, chemical composition analysis, dimensional measurements, and metallographic inspections are systematically executed.

• Ultrasonic Testing (UT): 100% testing performed according to SEP 1921 / ASTM E2375 to ensure internal soundness.
• Corrosion Testing: Intergranular and pitting corrosion testing conducted per ASTM A262 Practice A and E, validating PREN values.
• Certification: All materials accompanied by EN 10204 3.1 certificates; 3.2 certification available upon request.
• Third-Party Inspection: Services by SGS or TÜV can be arranged for independent verification.

ShunFu Metal operates under API Q1 and ISO 9001 quality management systems, guaranteeing consistent, traceable deliveries for all oilfield applications.

Packing and Shipping Guidelines

Packing protocols for Magnadur 501 are tailored to product finish and transport mode to guarantee oxidation-free arrival regardless of voyage duration. Black-skin forged bars are securely fastened with steel wire bundles, ensuring structural stability to prevent container damage during transit.

For bright-surface and precision-machined hollow bars and components, multi-layer packaging utilizing protective films and custom crates is applied. This safeguards the achieved surface roughness and dimensional accuracy against handling stresses. To counteract marine atmospheric conditions during overseas shipping, comprehensive anti-rust oil coatings are uniformly applied.

Request a Quote for Magnadur 501

Whether you require standard sized non-magnetic drill collar stock or custom forged Magnadur 501 hollow bars with precise internal geometries, ShunFu Metal is equipped to deliver. Our technical team is ready to assist you in selecting the optimal melting route and machining specifications for your downhole application.

Partner with a certified supplier committed to API Q1 standards and zero-defect delivery. Reach out today to discuss your project requirements and secure competitive pricing.