--- title: "FeE355KTTM — Fine-grain structural steels" description: "FeE355KTTM in UNI: material number 1.8834, also listed as S355ML. Category: Fine-grain structural steels. Designations recorded for this grade: 11." canonical: https://steelequivalents.com/materials/uni/fee355kttm language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/uni/fee355kttm.md cs: https://steelequivalents.com/cs/materiály/uni/fee355kttm.md de: https://steelequivalents.com/de/werkstoffe/uni/fee355kttm.md es: https://steelequivalents.com/es/materiales/uni/fee355kttm.md fr: https://steelequivalents.com/fr/matériaux/uni/fee355kttm.md hu: https://steelequivalents.com/hu/anyagok/uni/fee355kttm.md it: https://steelequivalents.com/it/materiali/uni/fee355kttm.md nl: https://steelequivalents.com/nl/materialen/uni/fee355kttm.md pl: https://steelequivalents.com/pl/materiały/uni/fee355kttm.md pt: https://steelequivalents.com/pt/materiais/uni/fee355kttm.md ru: https://steelequivalents.com/ru/материалы/uni/fee355kttm.md tr: https://steelequivalents.com/tr/malzemeler/uni/fee355kttm.md zh: https://steelequivalents.com/zh/材料/uni/fee355kttm.md ja: https://steelequivalents.com/ja/材料/uni/fee355kttm.md ar: https://steelequivalents.com/ar/المواد/uni/fee355kttm.md ko: https://steelequivalents.com/ko/재료/uni/fee355kttm.md pt-br: https://steelequivalents.com/pt-br/materiais/uni/fee355kttm.md hi: https://steelequivalents.com/hi/सामग्री/uni/fee355kttm.md content_hash: sha256:571d35088ee766d2f28a2265f3c298a5cf25f7930a8cc3fd697fc43e92cdbbf7 generated: 2026-09-22 --- > **Machine-readable Markdown rendering.** This is a Markdown representation of a web page, > served for AI agents and crawlers as a token-efficient alternative to the full HTML. > Full interactive HTML version: https://steelequivalents.com/materials/uni/fee355kttm > Canonical URL: https://steelequivalents.com/materials/uni/fee355kttm > Available languages: en, cs, de, es, fr, hu, it, nl, pl, pt, ru, tr, zh, ja, ar, ko, pt-br, hi > Change detection: `content_hash` is the SHA-256 of this document's Markdown body — everything > below this block, whitespace-trimmed, excluding the front-matter. Compare it to detect a real > content change; `generated` moves on every render and is not a change signal. UNI · Italy · 11 designations # FeE355KTTM FeE355KTTM is a designation in UNI for the material held under material number 1.8834, also listed as S355ML. It is a material in the category Fine-grain structural steels. We list 11 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, BS, AFNOR, UNI and SS. - [*Material no.* **1.8834**](/materials/material-no/1.8834 "Material no.: 1.8834") - [*Category* **Fine-grain structural steels · 50 grades**](/categories/fine-grain-structural-steels "Category: Fine-grain structural steels · 50 grades") - *Designations* **11** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=112a1c2f-2112-43de-aca1-6dfc2b442eac&designation=32c6996e-7f64-45ef-884c-5a4a2711b3cb "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/uni/fee355kttm.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN S355ML This grade’s own name](/materials/din-en/s355ml "DIN / EN S355ML") - [UNS K12000 This grade’s own name · 6 grades on that route](/materials/uns/k12000 "UNS K12000") ## About Fine-grain structural steels Fine-grain structural steel is a name for structural steels whose properties are particularly suitable for welding. They have a higher yield strength than comparable steels. Due to the negative influence of carbon on the weldability of a material, the maximum carbon content in fine-grained structural steels is less than 0.2%. These properties are achieved in steelmaking by the addition of oxygen and nitrogen-binding elements. The fine grain in the metallurgical structure is achieved by alloying elements whose nitrides and carbides only dissolve at higher temperatures. With the same composition, they are stronger and tougher than coarse-grained steels. Fine-grained structural steels are used above all in reinforced concrete structures such as bridges, in the construction of cranes, hydraulic cylinders or other welded structures due to their special welding suitability and in the offshore area. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 11 designations · 7 standards · nothing hidden This grade’s own name recorded in our sources as this grade’s own designation under that standard. Indicative taken from a published cross-reference table; a close match, not a guarantee of interchangeability. Verify against the mill certificate before ordering. Withdrawn designation no longer current — a separate column from the two above, so a name can be same grade and withdrawn at once. DIN / EN Europe · 4 - **FeE355KTTM Indicative** - [S355ML This grade’s own name](/materials/din-en/s355ml "DIN / EN S355ML") - [TStE 355 TM This grade’s own name Withdrawn](/materials/din-en/tste-355-tm "DIN / EN TStE 355 TM") - [TStE355 Indicative](/materials/din-en/tste355 "DIN / EN TStE355") UNS United States · 1 - [K12000 This grade’s own name](/materials/uns/k12000 "UNS K12000") AISI / SAE United States · 1 - [A633Gr.C Indicative](/materials/aisi-sae/a633gr-c "AISI / SAE A633Gr.C") BS United Kingdom · 1 - [50EE Indicative](/materials/bs/50ee "BS 50EE") AFNOR France · 1 - [E355FP Indicative](/materials/afnor/e355fp "AFNOR E355FP") UNI Italy · 2 - [FeE355KT Indicative](/materials/uni/fee355kt "UNI FeE355KT") - **FeE355KTTM Indicative** SS Sweden · 1 - [2135-01 Indicative](/materials/ss/2135-01 "SS 2135-01") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 14 elements on file · weight % What this alloy is Fe Mn Cu Si Iron — the balance, never listed by a standard — 96 % Mn — 1.6 % Cu — 0.6 % Si — 0.5 % Traces & impurities · 1.3 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.14 | | Si | ≤ 0.5 | | Mn | ≤ 1.6 | | P | 0.025 | | S | 0.02 | | Cr | ≤ 0.3 | | Mo | ≤ 0.1 | | Ni | 0.5 | | V | ≤ 0.1 | | Cu | ≤ 0.55 | | Al | ≥ 0.02 | | Ti | ≤ 0.05 | | Nb | ≤ 0.05 | | N | 0.015 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Vanadium Copper Aluminium Titanium Niobium Nitrogen 0.01 % 0.1 % 1 % 10 % 100 % 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 published source text, verbatim | Min% by weight | Max% by weight | Bound | |---|---|---|---|---| | C | ≤0,14 | — | 0.140 | Max | | N | 0,015 | 0.015 | 0.015 | Exact | | Al | ≥0,020 | 0.020 | — | Min | | Si | ≤0,50 | — | 0.500 | Max | | P | 0,025 | 0.025 | 0.025 | Exact | | S | 0,02 | 0.020 | 0.020 | Exact | | Ti | ≤0,05 | — | 0.050 | Max | | V | ≤0,10 | — | 0.100 | Max | | Cr | ≤0,30 | — | 0.300 | Max | | Mn | ≤1,60 | — | 1.600 | Max | | Ni | 0,5 | 0.500 | 0.500 | Exact | | Cu | ≤0,55 | — | 0.550 | Max | | Nb | ≤0,05 | — | 0.050 | Max | | Mo | ≤0,10 | — | 0.100 | 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 computed from composition · °C Predicted Ae3 820 °C Predicted Ae1 711 °C Predicted Acm 386 °C Predicted Bs 551 °C These four temperatures are a CALCULATION from this grade's own composition, using the published Li, Niebuhr, Meekisho & Atteridge (1998) model — never a measurement, and computed from the UPPER BOUND of each element's specified range, not a mid-range figure. Where this grade also has a measured transformation point (Ac1, Ac3, Ar1, Ar3) on file, it is shown separately, in Physical & mechanical properties, and is never replaced by the predicted figures here — Ae (predicted, equilibrium) and Ac/Ar (measured, on heating or cooling) are different physical quantities and can differ by tens of degrees; a mismatch between the two is not an error in either. ## Physical & mechanical properties Density 7,85 g/cm³ Exact 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 · 11 values By thickness**no delivery state stated** source `steelnumber` | Thickness mm | ReH N/mm² | Rm N/mm² | |---|---|---| | ≤ 16 | 355 | — | | 16 – 40 | 345 | — | | ≤ 40 | — | 470 – 630 | | 40 – 63 | 335 | 450 – 610 | | 63 – 80 | 325 | 440 – 600 | | 80 – 100 | 325 | 440 – 600 | | 100 – 120 | 320 | 430 – 590 | 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. ## Looking for this grade under another name? Search the catalogue by designation, material number or composition — every name on this page is itself a way in. [Search](/search "Steel grade search")[Inquiry](/inquiry?material=112a1c2f-2112-43de-aca1-6dfc2b442eac&designation=32c6996e-7f64-45ef-884c-5a4a2711b3cb "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/uni/fee355kttm.pdf "Datasheet as PDF")