--- title: "SWY21 — composition, equivalents and standards" description: "SWY21: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/jis/swy21 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/jis/swy21.md cs: https://steelequivalents.com/cs/materiály/jis/swy21.md de: https://steelequivalents.com/de/werkstoffe/jis/swy21.md es: https://steelequivalents.com/es/materiales/jis/swy21.md fr: https://steelequivalents.com/fr/matériaux/jis/swy21.md hu: https://steelequivalents.com/hu/anyagok/jis/swy21.md it: https://steelequivalents.com/it/materiali/jis/swy21.md nl: https://steelequivalents.com/nl/materialen/jis/swy21.md pl: https://steelequivalents.com/pl/materiały/jis/swy21.md pt: https://steelequivalents.com/pt/materiais/jis/swy21.md ru: https://steelequivalents.com/ru/материалы/jis/swy21.md tr: https://steelequivalents.com/tr/malzemeler/jis/swy21.md zh: https://steelequivalents.com/zh/材料/jis/swy21.md ja: https://steelequivalents.com/ja/材料/jis/swy21.md ar: https://steelequivalents.com/ar/المواد/jis/swy21.md ko: https://steelequivalents.com/ko/재료/jis/swy21.md pt-br: https://steelequivalents.com/pt-br/materiais/jis/swy21.md hi: https://steelequivalents.com/hi/सामग्री/jis/swy21.md content_hash: sha256:9091c255efa21a7f92111ca420852b6016ef5f394d311ef13455b68b91e61abe 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/jis/swy21 > Canonical URL: https://steelequivalents.com/materials/jis/swy21 > 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. JIS · Japan · 1 designation # SWY21 SWY21 is a grade designated under JIS. Its recorded composition includes C 0.1–0.15%, Si ≤ 0.03%, S ≤ 0.023%, Mn 0.35–0.65% and Cu ≤ 0.2%. No cross-standard equivalents are recorded for this grade yet. - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=43daeed1-dd69-4d3c-91c7-68d6b9c175a8&designation=0d9a3bc4-4b18-4efc-a3e9-857feebd0f94 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/jis/swy21.pdf "Datasheet as PDF") ## Chemical composition 6 elements on file · weight % What this alloy is Fe Mn Cu C Iron — the balance, never listed by a standard — 99.1 % Mn — 0.5 % Cu — 0.2 % C — 0.1 % Traces & impurities · 0.1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.1–0.15 | | Si | ≤ 0.03 | | Mn | 0.35–0.65 | | P | ≤ 0.02 | | S | ≤ 0.023 | | Cu | ≤ 0.2 | Carbon Silicon Manganese Phosphorus Sulfur Copper 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 | 0.1 - 0.15 | 0.100 | 0.150 | Range | | Si | max 0.03 | — | 0.030 | Max | | P | max 0.02 | — | 0.020 | Max | | S | max 0.023 | — | 0.023 | Max | | Mn | 0.35 - 0.65 | 0.350 | 0.650 | Range | | Cu | max 0.2 | — | 0.200 | 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. ## 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=43daeed1-dd69-4d3c-91c7-68d6b9c175a8&designation=0d9a3bc4-4b18-4efc-a3e9-857feebd0f94 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/jis/swy21.pdf "Datasheet as PDF")