--- title: "71Si7 — Spring steels" description: "71Si7: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/din-en/71si7 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/din-en/71si7.md cs: https://steelequivalents.com/cs/materiály/din-en/71si7.md de: https://steelequivalents.com/de/werkstoffe/din-en/71si7.md es: https://steelequivalents.com/es/materiales/din-en/71si7.md fr: https://steelequivalents.com/fr/matériaux/din-en/71si7.md hu: https://steelequivalents.com/hu/anyagok/din-en/71si7.md it: https://steelequivalents.com/it/materiali/din-en/71si7.md nl: https://steelequivalents.com/nl/materialen/din-en/71si7.md pl: https://steelequivalents.com/pl/materiały/din-en/71si7.md pt: https://steelequivalents.com/pt/materiais/din-en/71si7.md ru: https://steelequivalents.com/ru/материалы/din-en/71si7.md tr: https://steelequivalents.com/tr/malzemeler/din-en/71si7.md zh: https://steelequivalents.com/zh/材料/din-en/71si7.md ja: https://steelequivalents.com/ja/材料/din-en/71si7.md ar: https://steelequivalents.com/ar/المواد/din-en/71si7.md ko: https://steelequivalents.com/ko/재료/din-en/71si7.md pt-br: https://steelequivalents.com/pt-br/materiais/din-en/71si7.md hi: https://steelequivalents.com/hi/सामग्री/din-en/71si7.md content_hash: sha256:d7dcef9e73699354cbf582e0f8f2bd3b5422d0ab04439063ae3e7225e9c4c96c 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/71si7 > Canonical URL: https://steelequivalents.com/materials/din-en/71si7 > 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 · 1 designation # 71Si7 71Si7 is a material in the category [Spring steels](/categories/spring-steels "Spring steels"), held under material number 1.5029. Its recorded composition includes C 0.68–0.75%, Si 1.5–1.8%, P 0.035%, S 0.035% and Mn 0.6–0.8%. No cross-standard equivalents are recorded for this grade yet. Its recorded density is 7.85 g/cm³. - [*Material no.* **1.5029**](/materials/material-no/1.5029 "Material no.: 1.5029") - [*Category* **Spring steels · 52 grades**](/categories/spring-steels "Category: Spring steels · 52 grades") - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=5627b6e4-adc2-4813-b5d7-258aeead8ace&designation=bbe7462a-bc37-4610-8684-19c31decc7c5 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/71si7.pdf "Datasheet as PDF") ## 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. ## Chemical composition 5 elements on file · weight % What this alloy is Fe Si C Mn Iron — the balance, never listed by a standard — 96.9 % Si — 1.7 % C — 0.7 % Mn — 0.7 % Traces & impurities · 0.1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.68–0.75 | | Si | 1.5–1.8 | | Mn | 0.6–0.8 | | P | 0.035 | | S | 0.035 | 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 | 0,68-0,75 | 0.680 | 0.750 | Range | | Si | 1,50-1,80 | 1.500 | 1.800 | Range | | P | 0,035 | 0.035 | 0.035 | Exact | | S | 0,035 | 0.035 | 0.035 | Exact | | Mn | 0,60-0,80 | 0.600 | 0.800 | Range | 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 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 1.5, a shared category, and a published range for Si / Mn 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. [38Si7 1.5023 Si 1,50-1,80 · Mn 0,50-0,80 - ΔSi 0.00 - ΔMn 0.05 - 7 designations](/materials/din-en/38si7 "38Si7")[46Si7 1.5024 Si 1,50-1,80 · Mn 0,50-0,80 - ΔSi 0.00 - ΔMn 0.05 - 11 designations](/materials/din-en/46si7 "46Si7")[51Si7 1.5025 Si 1,50-1,80 · Mn 0,50-0,80 - ΔSi 0.00 - ΔMn 0.05 - 9 designations](/materials/din-en/51si7 "51Si7")[60Si7 1.5027 Si 1,50-1,80 · Mn 0,70-1,00 - ΔSi 0.00 - ΔMn 0.15 - 18 designations](/materials/din-en/60si7 "60Si7")[65Si7 1.5028 Si 1,50-1,80 · Mn 0,70-1,00 - ΔSi 0.00 - ΔMn 0.15 - 17 designations](/materials/din-en/65si7 "65Si7")[38Si6 1.5022 Si 1,40-1,60 · Mn 0,50-0,80 - ΔSi 0.15 - ΔMn 0.05 - 1 designations](/materials/din-en/38si6 "38Si6") ## 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=5627b6e4-adc2-4813-b5d7-258aeead8ace&designation=bbe7462a-bc37-4610-8684-19c31decc7c5 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/71si7.pdf "Datasheet as PDF")