--- title: "HPB300 — composition, equivalents and standards" description: "HPB300: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/gb/hpb300 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/hpb300.md cs: https://steelequivalents.com/cs/materiály/gb/hpb300.md de: https://steelequivalents.com/de/werkstoffe/gb/hpb300.md es: https://steelequivalents.com/es/materiales/gb/hpb300.md fr: https://steelequivalents.com/fr/matériaux/gb/hpb300.md hu: https://steelequivalents.com/hu/anyagok/gb/hpb300.md it: https://steelequivalents.com/it/materiali/gb/hpb300.md nl: https://steelequivalents.com/nl/materialen/gb/hpb300.md pl: https://steelequivalents.com/pl/materiały/gb/hpb300.md pt: https://steelequivalents.com/pt/materiais/gb/hpb300.md ru: https://steelequivalents.com/ru/материалы/gb/hpb300.md tr: https://steelequivalents.com/tr/malzemeler/gb/hpb300.md zh: https://steelequivalents.com/zh/材料/gb/hpb300.md ja: https://steelequivalents.com/ja/材料/gb/hpb300.md ar: https://steelequivalents.com/ar/المواد/gb/hpb300.md ko: https://steelequivalents.com/ko/재료/gb/hpb300.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/hpb300.md hi: https://steelequivalents.com/hi/सामग्री/gb/hpb300.md content_hash: sha256:bf8e341291d1f0e066e97f21a1307ead44ad31de0ad2a0f3c7c0e5896c10fbb7 generated: 2026-09-25 --- > **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/hpb300 > Canonical URL: https://steelequivalents.com/materials/gb/hpb300 > 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 · 1 designation # HPB300 HPB300 is a grade designated under GB. Its recorded composition includes C ≤ 0.25%, Si ≤ 0.55%, P ≤ 0.045%, S ≤ 0.045% and Mn ≤ 1.5%. No cross-standard equivalents are recorded for this grade yet. Recorded mechanical properties include Rm ≥ 420 N/mm². - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=25c3b7c9-e60a-4464-9a52-5ac21d19c7d5&designation=2904e42e-73a3-4b49-9dfb-30b941e94f73 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/hpb300.pdf "Datasheet as PDF") ## Chemical composition 5 elements on file · weight % What this alloy is Fe Mn Si C Iron — the balance, never listed by a standard — 97.6 % Mn — 1.5 % Si — 0.6 % C — 0.3 % Traces & impurities · 0.1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.25 | | Si | ≤ 0.55 | | Mn | ≤ 1.5 | | P | ≤ 0.045 | | S | ≤ 0.045 | Carbon Silicon Manganese Phosphorus Sulfur 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 | ≤0.25 | — | 0.250 | Max | | Si | ≤0.55 | — | 0.550 | Max | | P | ≤0.045 | — | 0.045 | Max | | S | ≤0.045 | — | 0.045 | Max | | Mn | ≤1.5 | — | 1.500 | 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 Rm ≥420 N/mm² Min 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=25c3b7c9-e60a-4464-9a52-5ac21d19c7d5&designation=2904e42e-73a3-4b49-9dfb-30b941e94f73 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/hpb300.pdf "Datasheet as PDF")