STC540
STC540 is a material in the category Unalloyed structural steels. Its recorded composition includes C ≤ 0.25%, Si ≤ 0.55%, P ≤ 0.04%, S ≤ 0.04% and Mn ≤ 1.6%. No cross-standard equivalents are recorded for this grade yet. Recorded mechanical properties include Rm 540 N/mm², Re 390 N/mm² and A 20%.
- Category Unalloyed structural steels · 452 grades
- Designations 1
About Unalloyed structural steels
Unalloyed structural steels include all low-carbon steels in which the iron companions do not exceed specified minimum values. The yield strength, formability and weldability are the decisive factors for their use. They are soft, pliable, tough and stretchy, but cannot be hardened by heat treatment.
This describes the material class as a whole. Always confirm the individual grade against the standard before ordering.
Chemical composition
5 elements on file · weight %What this alloy is
Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade.
| Element | % by weight |
|---|---|
≤ 0.25 | |
≤ 0.55 | |
≤ 1.6 | |
≤ 0.04 | |
≤ 0.04 |
The scale is logarithmic, not the element’s raw share of the alloy — the only honest way to fit 0.01 % and 100 % in one picture, and it means every value here can be compared with every other.
| Element | As publishedsource text, verbatim | Min% by weight | Max% by weight | Bound |
|---|---|---|---|---|
| C | max 0.25 | — | 0.250 | Max |
| Si | max 0.55 | — | 0.550 | Max |
| P | max 0.04 | — | 0.040 | Max |
| S | max 0.04 | — | 0.040 | Max |
| Mn | max 1.6 | — | 1.600 | Max |
The published column is the source string byte-for-byte, decimal comma and all; Min and Max are the parsed bounds. Elements not listed have no value on file — they are omitted, never inferred.
Predicted transformation temperatures
Not enough recorded composition to predict a transformation temperature for this grade — missing: Ni, Cr, Mo.
Physical & mechanical properties
An absent property means we hold no value for it — it is left out rather than estimated, interpolated from a neighbouring grade, or filled from a handbook. It does not mean the property is undefined for the material.
Properties by condition
1 conditions · 3 valuessteeljis| Delivery state | RmN/mm² | ReN/mm² | A% |
|---|---|---|---|
| Tubes | 540 | 390 | 20 |
Every figure holds only for the condition on its own row. Values are never merged across conditions or across sources, never averaged, and never interpolated between two rows. An em dash means no value on file — never zero. Figures are converted to the unit in the column header; the source’s own wording is kept and shown where the two differ.
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