--- title: "C78D2 — Spring steels" description: "C78D2: 5 equivalent designations across 3 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/din-en/c78d2 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/din-en/c78d2.md cs: https://steelequivalents.com/cs/materiály/din-en/c78d2.md de: https://steelequivalents.com/de/werkstoffe/din-en/c78d2.md es: https://steelequivalents.com/es/materiales/din-en/c78d2.md fr: https://steelequivalents.com/fr/matériaux/din-en/c78d2.md hu: https://steelequivalents.com/hu/anyagok/din-en/c78d2.md it: https://steelequivalents.com/it/materiali/din-en/c78d2.md nl: https://steelequivalents.com/nl/materialen/din-en/c78d2.md pl: https://steelequivalents.com/pl/materiały/din-en/c78d2.md pt: https://steelequivalents.com/pt/materiais/din-en/c78d2.md ru: https://steelequivalents.com/ru/материалы/din-en/c78d2.md tr: https://steelequivalents.com/tr/malzemeler/din-en/c78d2.md zh: https://steelequivalents.com/zh/材料/din-en/c78d2.md ja: https://steelequivalents.com/ja/材料/din-en/c78d2.md ar: https://steelequivalents.com/ar/المواد/din-en/c78d2.md ko: https://steelequivalents.com/ko/재료/din-en/c78d2.md pt-br: https://steelequivalents.com/pt-br/materiais/din-en/c78d2.md hi: https://steelequivalents.com/hi/सामग्री/din-en/c78d2.md content_hash: sha256:5361f1a0cb7c7230cd10a38a99eb12cd41054bbbbd0645cbda6321800ef46339 generated: 2026-09-22 --- > **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/din-en/c78d2 > Canonical URL: https://steelequivalents.com/materials/din-en/c78d2 > 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. DIN / EN · Europe · 5 designations # C78D2 C78D2 is a material in the category [Spring steels](/categories/spring-steels "Spring steels"), held under material number 1.1252. Its recorded composition includes C 0.76–0.8%, Si 0.1–0.3%, Cr ≤ 0.1%, Mn 0.5–0.7% and Cu ≤ 0.15%. We list 4 designations recorded for this grade, in the standards UNS and AISI / SAE. Its recorded density is 7.85 g/cm³. - [*Material no.* **1.1252**](/materials/material-no/1.1252 "Material no.: 1.1252") - [*Category* **Spring steels · 52 grades**](/categories/spring-steels "Category: Spring steels · 52 grades") - *Designations* **5** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=5a7365c4-7cb7-4688-bf1e-6990ceb32f20&designation=a8553e5a-aba9-4077-a9db-3ae9edc43e18 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/c78d2.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [UNS G10740 This grade’s own name · 6 grades on that route](/materials/uns/g10740 "UNS G10740") - [AISI / SAE 1074 This grade’s own name · 7 grades on that route](/materials/aisi-sae/1074 "AISI / SAE 1074") ## About Spring steels Spring steels are alloy steels designed to store and release elastic energy repeatedly without permanent deformation. They are characterised by a combination of strength, hardness and resilience, making them suitable for springs, clips, washers and other components subjected to repeated flexing or shock. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 5 designations · 3 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. DIN / EN Europe · 1 - **C78D2 This grade’s own name** UNS United States · 2 - [G10740 This grade’s own name](/materials/uns/g10740 "UNS G10740") - [G10750 This grade’s own name](/materials/uns/g10750 "UNS G10750") AISI / SAE United States · 2 - [1074 This grade’s own name](/materials/aisi-sae/1074 "AISI / SAE 1074") - [1075 This grade’s own name](/materials/aisi-sae/1075 "AISI / SAE 1075") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 11 elements on file · weight % What this alloy is Fe C Mn Si Iron — the balance, never listed by a standard — 98 % C — 0.8 % Mn — 0.6 % Si — 0.2 % Traces & impurities · 0.4 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.76–0.8 | | Si | 0.1–0.3 | | Mn | 0.5–0.7 | | P | 0.02 | | S | 0.025 | | Cr | ≤ 0.1 | | Mo | ≤ 0.03 | | Ni | ≤ 0.1 | | Cu | ≤ 0.15 | | Al | ≤ 0.01 | | N | 0.007 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Copper Aluminium Nitrogen 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 | 0,76-0,80 | 0.760 | 0.800 | Range | | N | 0,007 | 0.007 | 0.007 | Exact | | Al | ≤0,01 | — | 0.010 | Max | | Si | 0,10-0,30 | 0.100 | 0.300 | Range | | P | 0,02 | 0.020 | 0.020 | Exact | | S | 0,025 | 0.025 | 0.025 | Exact | | Cr | ≤0,10 | — | 0.100 | Max | | Mn | 0,50-0,70 | 0.500 | 0.700 | Range | | Ni | ≤0,10 | — | 0.100 | Max | | Cu | ≤0,15 | — | 0.150 | Max | | Mo | ≤0,03 | — | 0.030 | 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 This grade's composition falls outside the published model's validated range (a low-alloy composition window), so no transformation temperature is predicted here. ## Physical & mechanical properties Density 7,85 g/cm³ Exact 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. ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.1, a shared category, and a published range for Mn / Si that overlaps this grade’s. These are neighbours in composition space — they are not equivalents, and none is claimed to be interchangeable with this grade. [C76D2 1.1253 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.00 - ΔSi 0.00 - 5 designations](/materials/din-en/c76d2 "C76D2")[C86D2 1.1265 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.00 - ΔSi 0.00 - 6 designations](/materials/din-en/c86d2 "C86D2")[C85S 1.1269 Mn 0,40-0,70 · Si 0,15-0,35 - ΔMn 0.05 - ΔSi 0.05 - 33 designations](/materials/din-en/c85s "C85S")[C60S 1.1211 Mn 0,60-0,90 · Si 0,15-0,35 - ΔMn 0.15 - ΔSi 0.05 - 8 designations](/materials/din-en/c60s "C60S")[C67S 1.1231 Mn 0,60-0,90 · Si 0,15-0,35 - ΔMn 0.15 - ΔSi 0.05 - 42 designations](/materials/din-en/c67s "C67S")[C75S 1.1248 Mn 0,60-0,90 · Si 0,15-0,35 - ΔMn 0.15 - ΔSi 0.05 - 21 designations](/materials/din-en/c75s "C75S") ## 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=5a7365c4-7cb7-4688-bf1e-6990ceb32f20&designation=a8553e5a-aba9-4077-a9db-3ae9edc43e18 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/c78d2.pdf "Datasheet as PDF")