--- title: "STR11 — Heat resistant steels" description: "STR11: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/ks/str11 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/ks/str11.md cs: https://steelequivalents.com/cs/materiály/ks/str11.md de: https://steelequivalents.com/de/werkstoffe/ks/str11.md es: https://steelequivalents.com/es/materiales/ks/str11.md fr: https://steelequivalents.com/fr/matériaux/ks/str11.md hu: https://steelequivalents.com/hu/anyagok/ks/str11.md it: https://steelequivalents.com/it/materiali/ks/str11.md nl: https://steelequivalents.com/nl/materialen/ks/str11.md pl: https://steelequivalents.com/pl/materiały/ks/str11.md pt: https://steelequivalents.com/pt/materiais/ks/str11.md ru: https://steelequivalents.com/ru/материалы/ks/str11.md tr: https://steelequivalents.com/tr/malzemeler/ks/str11.md zh: https://steelequivalents.com/zh/材料/ks/str11.md ja: https://steelequivalents.com/ja/材料/ks/str11.md ar: https://steelequivalents.com/ar/المواد/ks/str11.md ko: https://steelequivalents.com/ko/재료/ks/str11.md pt-br: https://steelequivalents.com/pt-br/materiais/ks/str11.md hi: https://steelequivalents.com/hi/सामग्री/ks/str11.md content_hash: sha256:5b932da4e3cd7cf5338ecdce2ae1779ea650c7462d2fd0427e29bf30e9495253 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/ks/str11 > Canonical URL: https://steelequivalents.com/materials/ks/str11 > 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. KS · South Korea · 1 designation # STR11 STR11 is a material in the category [Heat resistant steels](/categories/heat-resistant-steels "Heat resistant steels"). Its recorded composition includes C 0.45–0.55%, Si 1–2%, Cr 7.5–9.5%, Mn ≤ 0.6% and Ni ≤ 0.6%. No cross-standard equivalents are recorded for this grade yet. Recorded mechanical properties include Rm 880 N/mm², Re 685 N/mm², A 15%, HB 262, Z 35% and aK 20 J/cm². - [*Category* **Heat resistant steels · 64 grades**](/categories/heat-resistant-steels "Category: Heat resistant steels · 64 grades") - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=e4d16d1e-8ab9-452f-8648-4f1faa57e1c3&designation=85942c7b-4694-440e-894d-7933c93bd91a "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/ks/str11.pdf "Datasheet as PDF") ## About Heat resistant steels Heat resistant steels are alloyed materials designed to retain useful mechanical properties and resist oxidation or scaling during service at elevated temperatures. They are used for components in furnaces, boilers, heat exchangers and power-generation equipment exposed to hot gases or sustained heat. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Chemical composition 7 elements on file · weight % What this alloy is Fe Cr Si Mn Iron — the balance, never listed by a standard — 88.2 % Cr — 8.5 % Si — 1.5 % Mn — 0.6 % Traces & impurities · 1.2 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.45–0.55 | | Si | 1–2 | | Mn | ≤ 0.6 | | P | ≤ 0.03 | | S | ≤ 0.03 | | Cr | 7.5–9.5 | | Ni | ≤ 0.6 | Carbon Silicon Manganese Phosphorus Sulfur Chromium 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 | 0.45 - 0.55 | 0.450 | 0.550 | Range | | Si | 1 - 2 | 1.000 | 2.000 | Range | | P | max 0.03 | — | 0.030 | Max | | S | max 0.03 | — | 0.030 | Max | | Cr | 7.5 - 9.5 | 7.500 | 9.500 | Range | | Mn | max 0.6 | — | 0.600 | Max | | Ni | max 0.6 | — | 0.600 | 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: 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. ## 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=e4d16d1e-8ab9-452f-8648-4f1faa57e1c3&designation=85942c7b-4694-440e-894d-7933c93bd91a "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/ks/str11.pdf "Datasheet as PDF")