--- title: "S255GT — Quenched and tempered steels" description: "S255GT in DIN / EN: material number 1.0408, also listed as E255. Category: Quenched and tempered steels. Designations recorded for this grade: 10." canonical: https://steelequivalents.com/materials/din-en/s255gt language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/din-en/s255gt.md cs: https://steelequivalents.com/cs/materiály/din-en/s255gt.md de: https://steelequivalents.com/de/werkstoffe/din-en/s255gt.md es: https://steelequivalents.com/es/materiales/din-en/s255gt.md fr: https://steelequivalents.com/fr/matériaux/din-en/s255gt.md hu: https://steelequivalents.com/hu/anyagok/din-en/s255gt.md it: https://steelequivalents.com/it/materiali/din-en/s255gt.md nl: https://steelequivalents.com/nl/materialen/din-en/s255gt.md pl: https://steelequivalents.com/pl/materiały/din-en/s255gt.md pt: https://steelequivalents.com/pt/materiais/din-en/s255gt.md ru: https://steelequivalents.com/ru/материалы/din-en/s255gt.md tr: https://steelequivalents.com/tr/malzemeler/din-en/s255gt.md zh: https://steelequivalents.com/zh/材料/din-en/s255gt.md ja: https://steelequivalents.com/ja/材料/din-en/s255gt.md ar: https://steelequivalents.com/ar/المواد/din-en/s255gt.md ko: https://steelequivalents.com/ko/재료/din-en/s255gt.md pt-br: https://steelequivalents.com/pt-br/materiais/din-en/s255gt.md hi: https://steelequivalents.com/hi/सामग्री/din-en/s255gt.md content_hash: sha256:917a614ac1924dbca04fa02f553af4689211f02afb5ab80e9d43e917b7ccd62d 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/din-en/s255gt > Canonical URL: https://steelequivalents.com/materials/din-en/s255gt > 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. DIN / EN · Europe · 10 designations # S255GT S255GT is a designation in DIN / EN for the material held under material number 1.0408, also listed as E255. It is a material in the category Quenched and tempered steels. We list 10 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE and ČSN. - [*Material no.* **1.0408**](/materials/material-no/1.0408 "Material no.: 1.0408") - [*Category* **Quenched and tempered steels · 133 grades**](/categories/quenched-and-tempered-steels "Category: Quenched and tempered steels · 133 grades") - *Designations* **10** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=32f5a530-9542-4278-b34e-3af7e827405c&designation=44ad268b-c345-4408-a758-5cab1efb1502 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/s255gt.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN E255 This grade’s own name](/materials/din-en/e255 "DIN / EN E255") - [UNS G10200 This grade’s own name · 8 grades on that route](/materials/uns/g10200 "UNS G10200") - [AISI / SAE 1020 This grade’s own name · 11 grades on that route](/materials/aisi-sae/1020 "AISI / SAE 1020") ## About Quenched and tempered steels Quenched and tempered steels are heat-treated steels designed to combine high strength with useful toughness and ductility. They are used for heavily loaded components such as shafts, gears, fasteners and structural machine parts where resistance to mechanical stress is required. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 10 designations · 4 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. Superseded by the current name this withdrawn designation was replaced by — the same grade under its present designation, the one to order by today. DIN / EN Europe · 4 - [E255 This grade’s own name](/materials/din-en/e255 "DIN / EN E255") - **S255GT This grade’s own name**Formerly St45 - [St 45.8 This grade’s own name](/materials/din-en/st45-8 "DIN / EN St 45.8") - [St45 Indicative Withdrawn](/materials/din-en/st45 "DIN / EN St45")Superseded by**S255GT** UNS United States · 2 - [G10200 This grade’s own name](/materials/uns/g10200 "UNS G10200") - [K03005 This grade’s own name](/materials/uns/k03005 "UNS K03005") AISI / SAE United States · 1 - [1020 This grade’s own name](/materials/aisi-sae/1020 "AISI / SAE 1020") ČSN Czechia · 3 - [10022 Indicative](/materials/csn/10022 "ČSN 10022") - [11 453 Indicative](/materials/csn/11453 "ČSN 11 453") - [12 022 Indicative](/materials/csn/12022 "ČSN 12 022") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 5 elements on file · weight % What this alloy is Fe Mn Si C Iron — the balance, never listed by a standard — 98.6 % Mn — 0.8 % Si — 0.4 % C — 0.2 % Traces & impurities · 0 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.21 | | Si | ≤ 0.35 | | Mn | 0.4–1.1 | | P | 0.025 | | S | 0.025 | Carbon Silicon Manganese Phosphorus Sulfur 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 | ≤0,21 | — | 0.210 | Max | | Si | ≤0,35 | — | 0.350 | Max | | P | 0,025 | 0.025 | 0.025 | Exact | | S | 0,025 | 0.025 | 0.025 | Exact | | Mn | 0,40-1,10 | 0.400 | 1.100 | Range | 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 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. ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.0, a shared category, and a published range for Mn / Si that overlaps this grade’s. These are neighbours in composition space — they are not equivalents, and none is claimed to be interchangeable with this grade. [1.0535 1.0535 Mn 0,60-0,90 · Si ≤0,40 - ΔMn 0.00 - ΔSi 0.03 - 101 designations](/materials/material-no/1.0535 "1.0535")[C50 1.0540 Mn 0,60-0,90 · Si ≤0,40 - ΔMn 0.00 - ΔSi 0.03 - 25 designations](/materials/din-en/c50 "C50")[1.0601 1.0601 Mn 0,60-0,90 · Si ≤0,40 - ΔMn 0.00 - ΔSi 0.03 - 92 designations](/materials/material-no/1.0601 "1.0601")[C26D 1.0415 Mn 0,50-0,80 · Si 0,10-0,30 - ΔMn 0.10 - ΔSi 0.03 - 8 designations](/materials/din-en/c26d "C26D")[1.0501 1.0501 Mn 0,50-0,80 · Si ≤0,40 - ΔMn 0.10 - ΔSi 0.03 - 123 designations](/materials/material-no/1.0501 "1.0501")[C35GPb 1.0502 Mn 0,50-0,80 · Si ≤0,40 - ΔMn 0.10 - ΔSi 0.03 - 2 designations](/materials/din-en/c35gpb "C35GPb") ## 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=32f5a530-9542-4278-b34e-3af7e827405c&designation=44ad268b-c345-4408-a758-5cab1efb1502 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/s255gt.pdf "Datasheet as PDF")