--- title: "ДИ-21 — composition, equivalents and standards" description: "ДИ-21 is a designation in GOST for the grade also listed as 08KH17N6T. We list 3 designations recorded for this grade, in the standards GOST." canonical: https://steelequivalents.com/materials/gost/di-21 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gost/di-21.md cs: https://steelequivalents.com/cs/materiály/gost/di-21.md de: https://steelequivalents.com/de/werkstoffe/gost/di-21.md es: https://steelequivalents.com/es/materiales/gost/di-21.md fr: https://steelequivalents.com/fr/matériaux/gost/di-21.md hu: https://steelequivalents.com/hu/anyagok/gost/di-21.md it: https://steelequivalents.com/it/materiali/gost/di-21.md nl: https://steelequivalents.com/nl/materialen/gost/di-21.md pl: https://steelequivalents.com/pl/materiały/gost/di-21.md pt: https://steelequivalents.com/pt/materiais/gost/di-21.md ru: https://steelequivalents.com/ru/материалы/gost/ди-21.md tr: https://steelequivalents.com/tr/malzemeler/gost/di-21.md zh: https://steelequivalents.com/zh/材料/gost/di-21.md ja: https://steelequivalents.com/ja/材料/gost/di-21.md ar: https://steelequivalents.com/ar/المواد/gost/di-21.md ko: https://steelequivalents.com/ko/재료/gost/di-21.md pt-br: https://steelequivalents.com/pt-br/materiais/gost/di-21.md hi: https://steelequivalents.com/hi/सामग्री/gost/di-21.md content_hash: sha256:8e69aa11f08a6e70e120c6f448baf5dc635ba3d73d1660e43661840c8040be32 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/gost/di-21 > Canonical URL: https://steelequivalents.com/materials/gost/di-21 > 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. GOST · Russia / CIS · 3 designations # ДИ-21 ДИ-21 is a designation in GOST for the grade also listed as 08KH17N6T. We list 3 designations recorded for this grade, in the standards GOST. - *Designations* **3** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=2c08ea2d-08ee-4488-9ca7-faed37ea7581&designation=9b39be81-f85e-45b0-a739-fa4b711c6502 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gost/di-21.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [GOST 08KH17N6T This grade’s own name](/materials/gost/08kh17n6t "GOST 08KH17N6T") ## Also known as 3 designations · 1 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. GOST Russia / CIS · 3 - [08KH17N6T This grade’s own name](/materials/gost/08kh17n6t "GOST 08KH17N6T") - [08Х17Н6Т Indicative](/materials/gost/08kh17n6t "GOST 08Х17Н6Т") - **ДИ-21 Indicative** Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 9 elements on file · weight % What this alloy is Fe Cr Ni Si Iron — the balance, never listed by a standard — 74.8 % Cr — 17.3 % Ni — 6 % Si — 0.8 % Traces & impurities · 1.2 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.08 | | Si | ≤ 0.8 | | Mn | ≤ 0.8 | | P | ≤ 0.035 | | S | ≤ 0.02 | | Cr | 16.5–18 | | Ni | 5.5–6.5 | | Ti | 0.15–0.35 | | B | ≤ 0.003 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Nickel Titanium Boron 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 | |---|---|---|---|---| | B | max 0.003 | — | 0.003 | Max | | C | max 0.08 | — | 0.080 | Max | | Si | max 0.8 | — | 0.800 | Max | | P | max 0.035 | — | 0.035 | Max | | S | max 0.02 | — | 0.020 | Max | | Ti | 0.15 - 0.35 | 0.150 | 0.350 | Range | | Cr | 16.5 - 18 | 16.500 | 18.000 | Range | | Mn | max 0.8 | — | 0.800 | Max | | Ni | 5.5 - 6.5 | 5.500 | 6.500 | 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: 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=2c08ea2d-08ee-4488-9ca7-faed37ea7581&designation=9b39be81-f85e-45b0-a739-fa4b711c6502 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gost/di-21.pdf "Datasheet as PDF")