--- title: "1.1209 — C55R, 15 equivalent designations" description: "1.1209 is the material number of the grade also listed as C55R. It is a material in the category Others. Designations recorded for this grade: 15." canonical: https://steelequivalents.com/materials/material-no/1.1209 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/material-no/1.1209.md cs: https://steelequivalents.com/cs/materiály/číslo-materiálu/1.1209.md de: https://steelequivalents.com/de/werkstoffe/werkstoff-nr/1.1209.md es: https://steelequivalents.com/es/materiales/número-de-material/1.1209.md fr: https://steelequivalents.com/fr/matériaux/numéro-de-matériau/1.1209.md hu: https://steelequivalents.com/hu/anyagok/anyagszám/1.1209.md it: https://steelequivalents.com/it/materiali/numero-materiale/1.1209.md nl: https://steelequivalents.com/nl/materialen/materiaalnummer/1.1209.md pl: https://steelequivalents.com/pl/materiały/numer-materiału/1.1209.md pt: https://steelequivalents.com/pt/materiais/número-do-material/1.1209.md ru: https://steelequivalents.com/ru/материалы/номер-материала/1.1209.md tr: https://steelequivalents.com/tr/malzemeler/malzeme-numarası/1.1209.md zh: https://steelequivalents.com/zh/材料/材料编号/1.1209.md ja: https://steelequivalents.com/ja/材料/材料番号/1.1209.md ar: https://steelequivalents.com/ar/المواد/رقم-المادة/1.1209.md ko: https://steelequivalents.com/ko/재료/재료번호/1.1209.md pt-br: https://steelequivalents.com/pt-br/materiais/número-do-material/1.1209.md hi: https://steelequivalents.com/hi/सामग्री/सामग्री-संख्या/1.1209.md content_hash: sha256:c7e1d70bb897a7cc20b6862d58d531b6e2f99625250a4f12e82bbc64b522722c generated: 2026-09-24 --- > **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/material-no/1.1209 > Canonical URL: https://steelequivalents.com/materials/material-no/1.1209 > 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. Material number · Europe · 15 designations # 1.1209 1.1209 is the material number of the grade also listed as C55R. It is a material in the category Others. We list 15 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, AFNOR, UNE, ISO, UNI, PN and AS / NZS. - ***Material no.* **1.1209**** - [*Category* **Others · 1754 grades**](/categories/others "Category: Others · 1754 grades") - *Designations* **15** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=c464df2f-2742-4232-92b3-489ee1fc8141 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/material-no/1.1209.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN C55R This grade’s own name](/materials/din-en/c55r "DIN / EN C55R") - [UNS G10550 This grade’s own name · 10 grades on that route](/materials/uns/g10550 "UNS G10550") - [AISI / SAE 1055 This grade’s own name · 10 grades on that route](/materials/aisi-sae/1055 "AISI / SAE 1055") ## About Others These are miscellaneous metallic alloys that do not fit a more specific material family and may be based on iron, nickel, cobalt, copper or other alloy systems. They are selected for applications requiring particular combinations of strength, hardness, toughness, wear resistance or resistance to demanding service conditions. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 15 designations · 9 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 · 2 - [C55R This grade’s own name](/materials/din-en/c55r "DIN / EN C55R") - [Cm 55 This grade’s own name Withdrawn](/materials/din-en/cm-55 "DIN / EN Cm 55") UNS United States · 2 - [G10550 This grade’s own name](/materials/uns/g10550 "UNS G10550") - [G10600 Indicative](/materials/uns/g10600 "UNS G10600") AISI / SAE United States · 2 - [1055 This grade’s own name](/materials/aisi-sae/1055 "AISI / SAE 1055") - [1060 Indicative](/materials/aisi-sae/1060 "AISI / SAE 1060") AFNOR France · 1 - [XC55H1u Indicative](/materials/afnor/xc55h1u "AFNOR XC55H1u") UNE Spain · 3 - [C55K1 Indicative](/materials/une/c55k1 "UNE C55K1") - [F1155 Indicative](/materials/une/f1155 "UNE F1155") - [F1155(1) Indicative](/materials/une/f1155-1 "UNE F1155(1)") ISO International · 1 - [C55M2 Indicative](/materials/iso/c55m2 "ISO C55M2") UNI Italy · 1 - [C55 Indicative](/materials/din-en/c55 "UNI C55") PN Poland · 2 - [55 Indicative](/materials/bds/55 "PN 55") - [60 Indicative](/materials/bds/60 "PN 60") AS / NZS Australia / New Zealand · 1 - [1055 Indicative](/materials/aisi-sae/1055 "AS / NZS 1055") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 8 elements on file · weight % What this alloy is Fe Mn C Si Iron — the balance, never listed by a standard — 97.3 % Mn — 0.8 % C — 0.6 % Si — 0.4 % Traces & impurities · 1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.52–0.6 | | Si | ≤ 0.4 | | Mn | 0.6–0.9 | | P | 0.03 | | S | 0.02–0.04 | | Cr | ≤ 0.4 | | Mo | ≤ 0.1 | | Ni | ≤ 0.4 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel 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 | 0,52-0,60 | 0.520 | 0.600 | Range | | Si | ≤0,40 | — | 0.400 | Max | | P | 0,03 | 0.030 | 0.030 | Exact | | S | 0,020-0,040 | 0.020 | 0.040 | Range | | Cr | ≤0,40 | — | 0.400 | Max | | Mn | 0,60-0,90 | 0.600 | 0.900 | Range | | Ni | ≤0,40 | — | 0.400 | 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 744 °C Predicted Ae1 723 °C Predicted Acm 687 °C Predicted Bs 547 °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 3 conditions · 8 values By thickness**Normalized** source `steelnumber` | Thickness mm | Rm N/mm² | A% | |---|---|---| | ≤ 16 | 680 | 11 | | 16 – 100 | 640 | 12 | | 100 – 250 | 620 | 12 | By delivery state**Treated to improve shearability** source `steelnumber` | Delivery state | HB | |---|---| | Treated to improve shearability | 255 | By delivery state**Soft annealed** source `steelnumber` | Delivery state | HB | |---|---| | Soft annealed | 229 | 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. ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.1, 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. [C53R 1.1205 Mn 0,60-0,90 · Si ≤0,40 - ΔMn 0.00 - ΔSi 0.00 - 2 designations](/materials/din-en/c53r "C53R")[Cm 60 Pb 1.1225 Mn 0,60-0,90 · Si ≤0,40 - ΔMn 0.00 - ΔSi 0.00 - 1 designations](/materials/din-en/cm-60-pb "Cm 60 Pb")[1.1203 1.1204 Mn 0,60-0,90 · Si 0,15-0,35 - ΔMn 0.00 - ΔSi 0.05 - 10 designations](/materials/material-no/1.1203 "1.1203")[Ck 60 Pb 1.1227 Mn 0,60-0,90 · Si 0,15-0,35 - ΔMn 0.00 - ΔSi 0.05 - 1 designations](/materials/din-en/ck-60-pb "Ck 60 Pb")[L360MS 1.1033 Mn ≤1,45 · Si ≤0,45 - ΔMn 0.03 - ΔSi 0.02 - 1 designations](/materials/din-en/l360ms "L360MS")[L390MS 1.1034 Mn ≤1,45 · Si ≤0,45 - ΔMn 0.03 - ΔSi 0.02 - 1 designations](/materials/din-en/l390ms "L390MS") ## 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=c464df2f-2742-4232-92b3-489ee1fc8141 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/material-no/1.1209.pdf "Datasheet as PDF")