--- title: "Ck 75 — Spring steels" description: "Ck 75 in DIN / EN: material number 1.1248, also listed as C75S. It is a material in the category Spring steels. Designations recorded for this grade: 21." canonical: https://steelequivalents.com/materials/din-en/ck-75 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/din-en/ck-75.md cs: https://steelequivalents.com/cs/materiály/din-en/ck-75.md de: https://steelequivalents.com/de/werkstoffe/din-en/ck-75.md es: https://steelequivalents.com/es/materiales/din-en/ck-75.md fr: https://steelequivalents.com/fr/matériaux/din-en/ck-75.md hu: https://steelequivalents.com/hu/anyagok/din-en/ck-75.md it: https://steelequivalents.com/it/materiali/din-en/ck-75.md nl: https://steelequivalents.com/nl/materialen/din-en/ck-75.md pl: https://steelequivalents.com/pl/materiały/din-en/ck-75.md pt: https://steelequivalents.com/pt/materiais/din-en/ck-75.md ru: https://steelequivalents.com/ru/материалы/din-en/ck-75.md tr: https://steelequivalents.com/tr/malzemeler/din-en/ck-75.md zh: https://steelequivalents.com/zh/材料/din-en/ck-75.md ja: https://steelequivalents.com/ja/材料/din-en/ck-75.md ar: https://steelequivalents.com/ar/المواد/din-en/ck-75.md ko: https://steelequivalents.com/ko/재료/din-en/ck-75.md pt-br: https://steelequivalents.com/pt-br/materiais/din-en/ck-75.md hi: https://steelequivalents.com/hi/सामग्री/din-en/ck-75.md content_hash: sha256:162560a5d77ace4b00b9ce5e13615d418f7d631c4371800a009f1572877dcd4a 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/ck-75 > Canonical URL: https://steelequivalents.com/materials/din-en/ck-75 > 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 · 21 designations # Ck 75 Ck 75 is a designation in DIN / EN for the material held under material number 1.1248, also listed as C75S. It is a material in the category Spring steels. We list 21 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, BS, AFNOR, JIS, GOST, ČSN, ABNT NBR, STN, PN and STAS. - [*Material no.* **1.1248**](/materials/material-no/1.1248 "Material no.: 1.1248") - [*Category* **Spring steels · 52 grades**](/categories/spring-steels "Category: Spring steels · 52 grades") - *Designations* **21** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=6a1cc436-d57c-427b-87bd-c73190ff627b&designation=942845bb-1301-4485-b8e4-bd9c8cf87efc "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/ck-75.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN C75S This grade’s own name](/materials/din-en/c75s "DIN / EN C75S") - [UNS G10700 This grade’s own name · 7 grades on that route](/materials/uns/g10700 "UNS G10700") - [AISI / SAE 1070 This grade’s own name · 7 grades on that route](/materials/aisi-sae/1070 "AISI / SAE 1070") ## 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 21 designations · 12 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 · 2 - [C75S This grade’s own name](/materials/din-en/c75s "DIN / EN C75S") - **Ck 75 This grade’s own name Withdrawn** UNS United States · 4 - [G10700 This grade’s own name](/materials/uns/g10700 "UNS G10700") - [G10740 This grade’s own name](/materials/uns/g10740 "UNS G10740") - [G10750 This grade’s own name](/materials/uns/g10750 "UNS G10750") - [G10780 This grade’s own name](/materials/uns/g10780 "UNS G10780") AISI / SAE United States · 5 - [1070 This grade’s own name](/materials/aisi-sae/1070 "AISI / SAE 1070") - [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") - [1078 This grade’s own name](/materials/aisi-sae/1078 "AISI / SAE 1078") - [1080 Indicative](/materials/aisi-sae/1080 "AISI / SAE 1080") BS United Kingdom · 1 - [CS80 Indicative](/materials/bs/cs80 "BS CS80") AFNOR France · 2 - [C75RR Indicative](/materials/afnor/c75rr "AFNOR C75RR") - [XC 75 Indicative](/materials/afnor/xc-75 "AFNOR XC 75") JIS Japan · 1 - [S 75 CM Indicative](/materials/jis/s75cm "JIS S 75 CM") GOST Russia / CIS · 1 - [75 Indicative](/materials/gost/75 "GOST 75") ČSN Czechia · 1 - [12081 Indicative](/materials/csn/12081 "ČSN 12081") ABNT NBR Brazil · 1 - [1074 Indicative](/materials/aisi-sae/1074 "ABNT NBR 1074") STN Slovakia · 1 - [12081 Indicative](/materials/csn/12081 "STN 12081") PN Poland · 1 - [75 Indicative](/materials/gost/75 "PN 75") STAS Romania · 1 - [OLC 75A Indicative](/materials/stas/olc-75a "STAS OLC 75A") 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 C Mn Cr Iron — the balance, never listed by a standard — 97.3 % C — 0.8 % Mn — 0.8 % Cr — 0.4 % Traces & impurities · 0.8 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.7–0.8 | | Si | 0.15–0.35 | | Mn | 0.6–0.9 | | P | 0.025 | | S | 0.025 | | Cr | ≤ 0.4 | | Mo | ≤ 0.1 | | Ni | ≤ 0.4 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel 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 | 0,70-0,80 | 0.700 | 0.800 | Range | | Si | 0,15-0,35 | 0.150 | 0.350 | Range | | P | 0,025 | 0.025 | 0.025 | Exact | | S | 0,025 | 0.025 | 0.025 | Exact | | Cr | ≤0,40 | — | 0.400 | Max | | Mn | 0,60-0,90 | 0.600 | 0.900 | Range | | Ni | ≤0,40 | — | 0.400 | Max | | Mo | ≤0,10 | — | 0.100 | 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. ## Properties by condition 6 conditions · 7 values By thickness**Soft annealed** source `steelnumber` | Thickness mm | Rm N/mm² | A80% | |---|---|---| | 0.3 – 3 | 640 | 15 | By thickness**Cold rolled** source `steelnumber` | Thickness mm | Rm N/mm² | |---|---| | 0.3 – 3 | 1170 | By thickness**Quenched and tempered** source `steelnumber` | Thickness mm | Rm N/mm² | |---|---| | 0.3 – 3 | 1200 – 1900 | By delivery state**Soft annealed** source `steelnumber` | Delivery state | HV | |---|---| | Soft annealed | 200 | By delivery state**Cold rolled** source `steelnumber` | Delivery state | HV | |---|---| | Cold rolled | 320 | By delivery state**Quenched and tempered** source `steelnumber` | Delivery state | HV | |---|---| | Quenched and tempered | 370 – 580 | 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. ## 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. [C60S 1.1211 Mn 0,60-0,90 · Si 0,15-0,35 - ΔMn 0.00 - ΔSi 0.00 - 8 designations](/materials/din-en/c60s "C60S")[C67S 1.1231 Mn 0,60-0,90 · Si 0,15-0,35 - ΔMn 0.00 - ΔSi 0.00 - 42 designations](/materials/din-en/c67s "C67S")[C85S 1.1269 Mn 0,40-0,70 · Si 0,15-0,35 - ΔMn 0.20 - ΔSi 0.00 - 33 designations](/materials/din-en/c85s "C85S")[C78D2 1.1252 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.15 - ΔSi 0.05 - 5 designations](/materials/din-en/c78d2 "C78D2")[C76D2 1.1253 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.15 - ΔSi 0.05 - 5 designations](/materials/din-en/c76d2 "C76D2")[C86D2 1.1265 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.15 - ΔSi 0.05 - 6 designations](/materials/din-en/c86d2 "C86D2") ## 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=6a1cc436-d57c-427b-87bd-c73190ff627b&designation=942845bb-1301-4485-b8e4-bd9c8cf87efc "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/ck-75.pdf "Datasheet as PDF")