TOM supplies UNS S31254 (254 SMO / 6Mo) stainless steel pipes and tubes to Japanese trading houses, EPCs, plant owners and OEMs - for seawater handling, desalination, FGD, chemical and high-purity service. ASTM A312 / A213 / A269, with third-party inspection and fast Asia-Pacific delivery.
What Is 254 SMO (UNS S31254)?
254 SMO is the widely used trade name for UNS S31254, a high-alloy super-austenitic stainless steel containing about 6 % molybdenum (hence "6Mo"). With roughly twice the pitting resistance of 316L and a PREN of 43–45, it delivers exceptional resistance to chloride pitting, crevice corrosion and stress-corrosion cracking in aggressive, chloride-rich environments.
Why 254 SMO for the Japanese Market
Japan operates one of the world's most demanding process and marine environments - long coastlines, dense chemical and semiconductor clusters, and a strong desalination / seawater-cooling tradition. 254 SMO is a natural fit:
Desalination & RO plants - feed, brine and high-pressure piping resisting chloride concentrations well beyond 316L limits.
Marine & offshore - seawater cooling, ballast, topside and platform piping with long service life.
FGD (flue gas desulfurization) - scrubber inlets, absorbers and ductwork in acidic, chloride-laden flue gas.
Chemical & pulp/paper - bleaching stages, acid-handling lines, and hot organic/media service.
Semiconductor & high-purity - ultra-clean, low-inclusion tubing for process and utility streams.
Heat exchangers & condensers - seamless and welded tubes with high strength and corrosion margin.
Standards & Product Range
|
Product |
Common ASTM / Standard |
Form |
Typical Size Range |
|
254 SMO Pipe (Seamless) |
ASTM A312 / A376 |
Seamless |
1/2" – 24" OD, SCH 5S–XXS |
|
254 SMO Pipe (Welded) |
ASTM A778 / A312 |
Welded |
1/2" – 48" OD |
|
254 SMO Tube (Seamless) |
ASTM A213 / A269 |
Seamless |
6 – 114 mm OD, wall 0.5–8 mm |
|
254 SMO Tube (Welded) |
ASTM A269 / A249 |
Welded |
Up to 100 mm OD (heat-exchanger grade) |
|
Fittings |
ASTM A403 / MSS SP-43 |
Elbow, tee, reducer, olet |
1/2" – 24" |
|
Flanges |
ASTM A182 / ASME B16.5 |
WN, SO, blind, lap-joint |
1/2" – 24", CL150–2500 |
|
Plate / Sheet |
ASTM A240 |
Plate |
3 – 50 mm thick |
Chemical Composition (UNS S31254)
|
Element |
C |
Cr |
Ni |
Mo |
N |
Cu |
Mn / Si |
P / S |
|
Typical % |
≤0.020 |
19.5–20.5 |
17.5–18.5 |
6.0–6.5 |
0.18–0.22 |
0.50–1.00 |
≤1.00 / ≤0.80 |
≤0.030 / ≤0.010 |
Mechanical Properties
|
Property |
Value (annealed) |
|
Tensile strength (min) |
≥ 650 MPa |
|
Yield strength 0.2% (min) |
≥ 300 MPa |
|
Elongation (min) |
≥ 35 % |
|
Hardness (max) |
≤ 100 HRB (≈ ≤ 220 HB) |
|
Density |
~ 8.0 g/cm³ |
|
PREN (Cr + 3.3Mo + 16N) |
~ 43–45 |
Why Source 254 SMO from TOM in Japan
Quality & Certification
EN 10204 3.1 mill certificate; 3.2 with TÜV / BV / SGS on request
PMI (positive material identification) on every heat
Hydrostatic, UT/ET, intergranular corrosion (A262) tests
ISO 9001 / material traceability to heat number
Supply & Service for Japan
OEM / ODM: sizes, ends, polishing, markings and packaging
Japan-oriented docs: JIS equivalence, Japanese inspection support
CIF / DAP major Japanese ports (Yokohama, Osaka, Kobe)
Fast Asia-Pacific lead times; small-lot flexibility
Frequently Asked Questions
Is 254 SMO weldable?
Yes. It is welded with a matching 6Mo filler (e.g. ERNiCrMo-type consumables) using proper purification and low heat input. TOM supplies welded pipe with full weld-procedure qualification on request.
254 SMO vs 316L vs 904L?
316L PREN ≈ 25, 904L ≈ 34, 254 SMO ≈ 44. For high chloride / seawater, 254 SMO offers the highest resistance and is often the cost-effective choice versus nickel alloys like 625.
Can you ship to Japan?
Yes. We deliver to Japanese ports and inland sites with complete export documentation, insurance and third-party inspection as required.
Related: Stainless Steel Pipe · Seamless & Welded Pipe · TOM Stainless Solutions
