Nickel Alloy 20 Flanges (UNS N08020)

As part of the MAASS GLOBAL GROUP, Maass Special Alloys supplies forged Alloy 20 flanges produced by Wilhelm Maass GmbH for demanding acid-related service. Also known as Carpenter 20, this nickel-iron-chromium alloy is specifically engineered for service in sulfuric acid environments. We deliver Blind, Welding Neck, and Socket Weld flanges directly from stock in multiple pressure classes.

High-quality Alloy 20 flanges

Designed for critical piping in corrosive service

Acid resistance

Strong resistance in sulfuric acid service.

Corrosion resistance

Resists acid-related corrosion and intergranular attack

Extensive stock

Blind, weld neck, socket weld.

Multiple classes

Class 150, 300, 600

Certified procurement

Supplied with EN 10204 certification.

Send your enquiry

Alloy 20 flanges in stock

Responsive Specificatie Tabel

Property	Value
Material	Alloy 20
Standard	ASME B16.5
UNS	N08020
Pressure classes	Class 150, Class 300 and Class 600
Available sizes	½″ – 6″ (Blind & Welding Neck) / ½″ – 2″ (Socket Weld)
Product form	Forged finish

Need Alloy 20 flanges for a specific requirement? Maass supplies high-grade forged flanges directly from stock. Our inventory includes the most requested types and pressure classes to ensure quick delivery for your chemical processing and piping projects.

Certified supply & additional information

EN 10204 3.1 documentation available where applicable
Additional inspection documentation available on request
Stock or production supply
Produced by Wilhelm Maass GmbH
Suitable for projects requiring DNV, Lloyd’s or NORSOK M-630 related documentation and approval routes.
Stock availability subject to current inventory

Upon request‍

Additional flange types (Slip-Ons, Threaded, Lap-Joint, Orifice, Reducing Flanges)
Custom manufacturing according to drawings
Extended sizes up to 36”
Higher pressure classes (Class 900, Class 1500, and Class 2500)
Additional testing and third-party inspection

Chemical composition

The composition of Alloy 20 / UNS N08020 is designed to combine strong corrosion resistance with reliable performance in acid-related service.

Below chemical composition limits are provided for quick reference. Final compliance is confirmed by the Mill Test Certificate (EN 10204) and the order specification.

Element	Limit (%)
Nickel (Ni)	32.0 – 38.0
Chromium (Cr)	19.0 – 21.0
Copper (Cu)	3.0 – 4.0
Molybdenum (Mo)	2.0 – 3.0
Iron (Fe)	Balance
Carbon (C)	0.07 max.
Niobium + Tantalum (Nb+Ta)	8xC min. – 1.0 max
Manganese (Mn)	2.0 max.
Phosphorus (P)	0.045 max.
Sulfur (S)	0.035 max.
Silicon (Si)	1.0 max.

Typical physical and mechanical properties of Alloy 20

The values below provide a general indication of the typical physical and mechanical properties of a forged Alloy 20 flange. These values are intended as typical material data only, since actual values may vary depending on size and supply condition.

Property	Unit	Typical value
Density	lb/in³	0.292
Melting range	°F	2520 – 2600
Specific heat	Btu/lb-°F	0.12
Elastic modulus	10³ ksi	28.0
Shear modulus	10³ ksi	11.0
Poisson’s ratio	-	0.31
Thermal conductivity	Btu-in/ft²-h-°F	85
Coefficient of expansion	10^-6 in/in-°F	8.2
Tensile strength	ksi	80 min.
Yield strength	ksi	35 min.
Elongation	%	40

Get your quote

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Mail us

sales@maass-special-alloys.com

Call us

+31 (0)30 8200 370