Stainless steel

254 SMO

Manufacturer or standards-body identification; product values do not apply to every form or condition.

Specific property examples

What distinguishes this material

The cited seamless tube/pipe data separate wall thickness below and above 5 mm. The manufacturer calls 1.4529 a nearest equivalent, not an identical designation.

Designation in this reference

254 SMO / UNS S31254

Forms covered by the sources

Alleima seamless tube and pipe.

States to distinguish or confirm

Solution-annealed, white-pickled or bright-annealed supplier condition.

Temperature and exposure

The example applies at 20°C to the cited solution-annealed seamless tube/pipe with wall thickness below 5 mm; it is not a bar/plate property card.

Other search names in these sources

UNS S31254 · 1.4547

Read the scope above: a source’s related product name is not a blanket interchangeability statement.

Property evidence for a stated condition

Read the complete example before using a number. Typical values are not guaranteed limits. Missing test conditions remain visible.

Specific source example

Alleima 254 SMO seamless tube/pipe, wall <5 mm

Product / specimen: Seamless tube/pipe, wall thickness <5 mm
Condition: Supplier solution-annealed delivery
Test temperature / environment: 20°C

Values apply to the example above
Property	Value	Meaning and method
0.2% proof strength	≥310 MPa	minimum Rp0.2; supplier mechanical-properties table.
Tensile strength	675–850 MPa	range Rm; supplier mechanical-properties table.
Hardness	≤96 HRB	maximum Rockwell B, supplier mechanical-properties table.

Alleima 254 SMO seamless tube and pipe data ↗

Resolve these conditions next

What product standard, edition and complete grade are on the material certificate?
What product form, section size and delivery/heat-treatment condition will be machined?

For machining, take the exact grade, supplied condition and measured hardness where applicable into the tool maker’s application data. A generic material-family speed is not a substitute for an operation and tool-specific recommendation.

Continue to a machining task →Check specified size limits →

Sources and what they establish

Reviewed 23 October 2026. A source’s publication date and the review date are different. The scope below identifies the fields checked.

Alleima 254 SMO seamless tube and pipe data

Updated 2026-08-17; S31254, solution-annealed seamless tube/pipe and 20°C properties split by wall thickness.

Alleima 254 SMO seamless tube and pipe data ↗

Source identity, a named product example and a supplied-batch certificate are different evidence. Cross-standard similarity does not approve substitution.

Corrections from the previous article

Retain S31254/1.4547 identity; do not present 1.4529 as exact equivalence or apply thin-wall tube strengths to all bar/plate products.
Withdraw the legacy generic hardness (95 HRB) and tensile-strength (650 MPa (94 ksi)) pair: the old page does not establish a matching product, heat treatment, section and test source.
Remove the unsupported cutting-speed table and machinability percentage; select tooling only after the actual material condition is known.

See this page’s review record →

Other references in Stainless steel

Related references, not equivalent substitutes.

13-8 Mo Stainless →15-5 PH →17-4 PH →Browse this family →