--- title: "HT400 — composition, equivalents and standards" description: "HT400 is a designation in GB for the grade also listed as No 55 B. Designations recorded for this grade: 5." canonical: https://steelequivalents.com/materials/gb/ht400 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/ht400.md cs: https://steelequivalents.com/cs/materiály/gb/ht400.md de: https://steelequivalents.com/de/werkstoffe/gb/ht400.md es: https://steelequivalents.com/es/materiales/gb/ht400.md fr: https://steelequivalents.com/fr/matériaux/gb/ht400.md hu: https://steelequivalents.com/hu/anyagok/gb/ht400.md it: https://steelequivalents.com/it/materiali/gb/ht400.md nl: https://steelequivalents.com/nl/materialen/gb/ht400.md pl: https://steelequivalents.com/pl/materiały/gb/ht400.md pt: https://steelequivalents.com/pt/materiais/gb/ht400.md ru: https://steelequivalents.com/ru/материалы/gb/ht400.md tr: https://steelequivalents.com/tr/malzemeler/gb/ht400.md zh: https://steelequivalents.com/zh/材料/gb/ht400.md ja: https://steelequivalents.com/ja/材料/gb/ht400.md ar: https://steelequivalents.com/ar/المواد/gb/ht400.md ko: https://steelequivalents.com/ko/재료/gb/ht400.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/ht400.md hi: https://steelequivalents.com/hi/सामग्री/gb/ht400.md content_hash: sha256:24a8ca6e53f44453554c984f2850f225c54fb031ff28e75edbb2acec21525209 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/gb/ht400 > Canonical URL: https://steelequivalents.com/materials/gb/ht400 > 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. GB · China · 5 designations # HT400 HT400 is a designation in GB for the grade also listed as No 55 B. We list 5 designations recorded for this grade, in the standards AISI / SAE, BS, AFNOR, GB and SS. - *Designations* **5** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=eccbb148-8327-4ecc-acaa-78986d93d7ae&designation=c1fca334-b33d-4a5b-abca-a5d4fd375aec "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/ht400.pdf "Datasheet as PDF") ## Also known as 5 designations · 5 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. AISI / SAE United States · 1 - [No 55 B Indicative](/materials/aisi-sae/no-55-b "AISI / SAE No 55 B") BS United Kingdom · 1 - [Grade 400 Indicative](/materials/bs/grade-400 "BS Grade 400") AFNOR France · 1 - [Ft 40 D Indicative](/materials/afnor/ft-40-d "AFNOR Ft 40 D") GB China · 1 - **HT400 This grade’s own name** SS Sweden · 1 - [0140 Indicative](/materials/ss/0140 "SS 0140") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Predicted transformation temperatures Not enough recorded composition to predict a transformation temperature for this grade — missing: C, Mn, Si, 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=eccbb148-8327-4ecc-acaa-78986d93d7ae&designation=c1fca334-b33d-4a5b-abca-a5d4fd375aec "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/ht400.pdf "Datasheet as PDF")