--- title: "ПК70Д3-7.4 — composition, equivalents and standards" description: "ПК70Д3-7.4 is a designation in GOST for the grade also listed as 70S3А. We list 10 designations recorded for this grade, in the standards GOST." canonical: https://steelequivalents.com/materials/gost/pk70d3-7-4 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gost/pk70d3-7-4.md cs: https://steelequivalents.com/cs/materiály/gost/pk70d3-7-4.md de: https://steelequivalents.com/de/werkstoffe/gost/pk70d3-7-4.md es: https://steelequivalents.com/es/materiales/gost/pk70d3-7-4.md fr: https://steelequivalents.com/fr/matériaux/gost/pk70d3-7-4.md hu: https://steelequivalents.com/hu/anyagok/gost/pk70d3-7-4.md it: https://steelequivalents.com/it/materiali/gost/pk70d3-7-4.md nl: https://steelequivalents.com/nl/materialen/gost/pk70d3-7-4.md pl: https://steelequivalents.com/pl/materiały/gost/pk70d3-7-4.md pt: https://steelequivalents.com/pt/materiais/gost/pk70d3-7-4.md ru: https://steelequivalents.com/ru/материалы/gost/пк70д3-7.4.md tr: https://steelequivalents.com/tr/malzemeler/gost/pk70d3-7-4.md zh: https://steelequivalents.com/zh/材料/gost/pk70d3-7-4.md ja: https://steelequivalents.com/ja/材料/gost/pk70d3-7-4.md ar: https://steelequivalents.com/ar/المواد/gost/pk70d3-7-4.md ko: https://steelequivalents.com/ko/재료/gost/pk70d3-7-4.md pt-br: https://steelequivalents.com/pt-br/materiais/gost/pk70d3-7-4.md hi: https://steelequivalents.com/hi/सामग्री/gost/pk70d3-7-4.md content_hash: sha256:c28b1f51b63c76277503f27406efef27e2cd047cc2895ddc4d982e0b35a15285 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/pk70d3-7-4 > Canonical URL: https://steelequivalents.com/materials/gost/pk70d3-7-4 > 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 · 10 designations # ПК70Д3-7.4 ПК70Д3-7.4 is a designation in GOST for the grade also listed as 70S3А. We list 10 designations recorded for this grade, in the standards GOST. - *Designations* **10** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=d343c101-2951-44fb-9fc2-18d0104f29f1&designation=94535b4a-cc12-4452-86b9-89692b1cddf9 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gost/pk70d3-7-4.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [GOST 70S3А This grade’s own name](/materials/gost/70s3a "GOST 70S3А") ## Also known as 10 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 · 10 - [70S3А This grade’s own name](/materials/gost/70s3a "GOST 70S3А") - [70С3А Indicative](/materials/gost/70s3a "GOST 70С3А") - [PK70D3 Indicative](/materials/gost/pk70d3 "GOST PK70D3") - [PK70Kh3 Indicative](/materials/gost/pk70kh3 "GOST PK70Kh3") - [ПК70Д3-6.0 Indicative](/materials/gost/pk70d3-6-0 "GOST ПК70Д3-6.0") - [ПК70Д3-6.4 Indicative](/materials/gost/pk70d3-6-4 "GOST ПК70Д3-6.4") - [ПК70Д3-6.8 Indicative](/materials/gost/pk70d3-6-8 "GOST ПК70Д3-6.8") - **ПК70Д3-7.4 Indicative** - [ПК70Х3-6.4 Indicative](/materials/gost/pk70kh3-6-4 "GOST ПК70Х3-6.4") - [ПК70Х3-6.8 Indicative](/materials/gost/pk70kh3-6-8 "GOST ПК70Х3-6.8") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 8 elements on file · weight % What this alloy is Fe Si Mn C Iron — the balance, never listed by a standard — 95.2 % Si — 2.6 % Mn — 0.8 % C — 0.7 % Traces & impurities · 0.8 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.66–0.74 | | Si | 2.4–2.8 — Unusual | | Mn | 0.6–0.9 | | P | ≤ 0.025 | | S | ≤ 0.025 | | Cr | ≤ 0.3 | | Ni | ≤ 0.25 | | Cu | ≤ 0.2 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Nickel 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 | 0.66 - 0.74 | 0.660 | 0.740 | Range | | Si | 2.4 - 2.8 | 2.400 | 2.800 | Range | | P | max 0.025 | — | 0.025 | Max | | S | max 0.025 | — | 0.025 | Max | | Cr | max 0.3 | — | 0.300 | Max | | Mn | 0.6 - 0.9 | 0.600 | 0.900 | Range | | Ni | max 0.25 | — | 0.250 | Max | | 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: Mo. ## Physical & mechanical properties Transformation point Ac1 765 °C Exact Transformation point Ac3 780 °C Exact · Ac3(Acm) Weldability not suitable for welding As published: is not used. Flake sensitivity not susceptible As published: not predisposed Temper brittleness slightly susceptible As published: weakly predisposed 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. ## Properties by condition 3 conditions · 40 values By delivery state**no delivery state stated** source `splav` | Delivery state | HB | |---|---| | (annealing) , GOST 14959-79 | 269 | | (without heat treatment) , GOST 14959 | 302 | By heat-treated condition**no delivery state stated** source `splav` | Heat-treated condition | Rm N/mm² | Re N/mm² | A5% | Z% | |---|---|---|---|---| | Rolled stock, GOST 14959-79 | 1670 | 1470 | 6 | 25 | At temperature**no delivery state stated** source `splav` | Temperature °C | Elastic modulus GPa | Thermal expansion coefficient 10^-6/K | Thermal conductivity W/(m·K) | Specific heat capacity J/(kg·K) | |---|---|---|---|---| | 20 | 214 | — | 25 | — | | 100 | 208 | 11.4 | 26 | 480 | | 200 | 198 | 12.3 | 27 | 510 | | 300 | 192 | 12.8 | 28 | 520 | | 400 | 185 | 13.3 | 29 | 535 | | 500 | 180 | 13.7 | 29 | 565 | | 600 | 152 | 14.1 | 29 | 585 | | 700 | 139 | 14.3 | 28 | 620 | | 800 | 132 | 12.8 | 27 | 700 | Every figure holds only for the condition on its own row. Values are never merged across conditions or across sources, never averaged, and never interpolated between two rows. An em dash means no value on file — never zero. Figures are converted to the unit in the column header; the source’s own wording is kept and shown where the two differ. ## 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=d343c101-2951-44fb-9fc2-18d0104f29f1&designation=94535b4a-cc12-4452-86b9-89692b1cddf9 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gost/pk70d3-7-4.pdf "Datasheet as PDF")