254 SMO Steel Pipe

1. Standard: ASTM A312, ASME SA 312
2. Size: 1/2''~48''
3. Thickness: SCH5~SCHXXS
4. Service: Cutting, Welding, Fabricated, Customized

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Product Introduction

254 SMO steel pipe (also known as UNS S31254 or 6 moly pipe) is a super austenitic stainless steel engineered specifically for environments where standard 316L or duplex grades simply fail. At HT PIPE, we specialize in high-performance stainless steel and alloy piping for demanding industrial application

With a PREN (Pitting Resistance Equivalent Number) above 43, it ranks among the most corrosion-resistant austenitic alloys commercially available - making it the go-to choice for engineers handling seawater, chloride-rich process streams, and aggressive chemical media.

We offers 254 SMO steel in a variety of forms, including:

Bar
Wire
Sheet
Plate
Forgings
Pipe fittings
Flanges
Seamless & Welded pipe
Seamless Tube & Welded tube
Weld Rod

SMO 254 / UNS S31254 Tubes Specifications

Specifications	ASTM A 269 ASME SA 269 / ASTM A 249 ASME SA 249
Dimensions	ASTM, ASME and API
Size	3/4″ – 12″
Thickness	20 Swg, 18 Swg, 16 Swg, 14 Swg, 12 Swg, 10 Swg, & Sch10, Sch40, Sch80 etc.
Type	Seamless / ERW / Welded / Fabricated
Form	Round Tubes, Custom Tubes, Square Tubes, Rectangular Tubes, "U" Shape, Hydraulic Tubes
Length	Single Random, Double Random & Cut Length.
End	Plain End, Beveled End, Treaded

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Key Chemical Composition

Element	Content (wt%)
Chromium (Cr)	19.5 – 20.5
Nickel (Ni)	17.5 – 18.5
Molybdenum (Mo)	6.0 – 6.5 ★
Copper (Cu)	0.50 – 1.00
Nitrogen (N)	0.18 – 0.22
Carbon (C)	≤ 0.020

Mechanical & Physical Properties

Property	Value
Tensile Strength	≥ 690 MPa (100 ksi)
Yield Strength	≥ 310 MPa (45 ksi)
Elongation	≥ 35%
Hardness	≤ 96 HRB
Density	8.0 g/cm³
Non-magnetic	Yes

Where Is 254 SMO Pipe Used?

Marine & Seawater Systems: Offshore platforms, seawater cooling loops, ballast water systems, FPSO piping - anywhere continuous seawater contact is unavoidable.

Desalination Plants: The preferred piping material for MSF and RO desalination systems worldwide, thanks to its ability to handle hot, concentrated brine without pitting.

Chemical Processing: Handles chloride-bearing process streams, sulfuric acid at moderate concentrations, and phosphoric acid systems that destroy 316L in weeks.

Pulp & Paper Industry: Specified for bleaching stage piping (chlorine dioxide, hypochlorite environments) in pulp mills - one of the most aggressive industrial environments for steel.

Flue Gas Desulfurization (FGD): Used in FGD scrubbers and stack liners where wet sulfuric acid and chlorides combine to create extreme corrosion conditions.

Oil & Gas: Sour service (H₂S-containing) piping, seawater injection systems, and subsea components requiring long service life with minimal maintenance.

Pharmaceutical & Food Processing: Non-magnetic, easy-to-clean, and resistant to the aggressive CIP (clean-in-place) chemicals used in sanitary process systems.