--- title: "E4340 Mod — Quenched and tempered steels" description: "E4340 Mod in AISI / SAE: material number 1.6562, also listed as 40NiCrMo8-4. It is a material in the category Quenched and tempered steels." canonical: https://steelequivalents.com/materials/aisi-sae/e4340-mod language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/aisi-sae/e4340-mod.md cs: https://steelequivalents.com/cs/materiály/aisi-sae/e4340-mod.md de: https://steelequivalents.com/de/werkstoffe/aisi-sae/e4340-mod.md es: https://steelequivalents.com/es/materiales/aisi-sae/e4340-mod.md fr: https://steelequivalents.com/fr/matériaux/aisi-sae/e4340-mod.md hu: https://steelequivalents.com/hu/anyagok/aisi-sae/e4340-mod.md it: https://steelequivalents.com/it/materiali/aisi-sae/e4340-mod.md nl: https://steelequivalents.com/nl/materialen/aisi-sae/e4340-mod.md pl: https://steelequivalents.com/pl/materiały/aisi-sae/e4340-mod.md pt: https://steelequivalents.com/pt/materiais/aisi-sae/e4340-mod.md ru: https://steelequivalents.com/ru/материалы/aisi-sae/e4340-mod.md tr: https://steelequivalents.com/tr/malzemeler/aisi-sae/e4340-mod.md zh: https://steelequivalents.com/zh/材料/aisi-sae/e4340-mod.md ja: https://steelequivalents.com/ja/材料/aisi-sae/e4340-mod.md ar: https://steelequivalents.com/ar/المواد/aisi-sae/e4340-mod.md ko: https://steelequivalents.com/ko/재료/aisi-sae/e4340-mod.md pt-br: https://steelequivalents.com/pt-br/materiais/aisi-sae/e4340-mod.md hi: https://steelequivalents.com/hi/सामग्री/aisi-sae/e4340-mod.md content_hash: sha256:82d35ef4b4f432838f2151c5e94028f9c8d182ab67c86dc262403b97a897a656 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/aisi-sae/e4340-mod > Canonical URL: https://steelequivalents.com/materials/aisi-sae/e4340-mod > 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. AISI / SAE · United States · 33 designations # E4340 Mod E4340 Mod is a designation in AISI / SAE for the material held under material number 1.6562, also listed as 40NiCrMo8-4. It is a material in the category Quenched and tempered steels. We list 33 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ASTM, BS, AFNOR, SAE AMS, GOST, UNI, PN and MKE. - [*Material no.* **1.6562**](/materials/material-no/1.6562 "Material no.: 1.6562") - [*Category* **Quenched and tempered steels · 133 grades**](/categories/quenched-and-tempered-steels "Category: Quenched and tempered steels · 133 grades") - *Designations* **33** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=95b93c8a-977b-4b13-8b34-bf4abb4f212b&designation=aeda8507-1240-4449-a3f3-5e7c8d87c82b "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/aisi-sae/e4340-mod.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN 40 NiCrMo 8 4 This grade’s own name](/materials/din-en/40nicrmo8-4 "DIN / EN 40 NiCrMo 8 4") - [UNS G43370 This grade’s own name · 2 grades on that route](/materials/uns/g43370 "UNS G43370") - [AISI / SAE 4337 This grade’s own name · 3 grades on that route](/materials/aisi-sae/4337 "AISI / SAE 4337") ## About Quenched and tempered steels Quenched and tempered steels are heat-treated steels designed to combine high strength with useful toughness and ductility. They are used for heavily loaded components such as shafts, gears, fasteners and structural machine parts where resistance to mechanical stress is required. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 33 designations · 11 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 - [40 NiCrMo 8 4 This grade’s own name](/materials/din-en/40nicrmo8-4 "DIN / EN 40 NiCrMo 8 4") - [40NiCrMo8-4 This grade’s own name](/materials/din-en/40nicrmo8-4 "DIN / EN 40NiCrMo8-4") UNS United States · 5 - [G43370 This grade’s own name](/materials/uns/g43370 "UNS G43370") - [G43376 This grade’s own name](/materials/uns/g43376 "UNS G43376") - [G43406 Indicative](/materials/uns/g43406 "UNS G43406") - [H43406 This grade’s own name](/materials/uns/h43406 "UNS H43406") - [K24064 This grade’s own name](/materials/uns/k24064 "UNS K24064") AISI / SAE United States · 6 - [4337 This grade’s own name](/materials/aisi-sae/4337 "AISI / SAE 4337") - [4340 Indicative](/materials/aisi-sae/4340 "AISI / SAE 4340") - [E4337 This grade’s own name](/materials/aisi-sae/e4337 "AISI / SAE E4337") - [E4340 Indicative](/materials/aisi-sae/e4340 "AISI / SAE E4340") - **E4340 Mod Indicative** - [E4340H This grade’s own name](/materials/aisi-sae/e4340h "AISI / SAE E4340H") ASTM United States · 2 - [A322 Indicative](/materials/astm/a322 "ASTM A322") - [A331 Indicative](/materials/astm/a331 "ASTM A331") BS United Kingdom · 2 - [817M40 Indicative](/materials/bs/817m40 "BS 817M40") - [S155 Indicative](/materials/bs/s155 "BS S155") AFNOR France · 1 - [40 NCD 7 Indicative](/materials/afnor/40-ncd-7 "AFNOR 40 NCD 7") SAE AMS United States / Aerospace · 8 - [6257 Indicative bar forging](/materials/ams/6257 "SAE AMS 6257") - [6359 Indicative plate sheet strip](/materials/ams/6359 "SAE AMS 6359") - [6409 Indicative bar forging](/materials/ams/6409 "SAE AMS 6409") - [6414 Indicative bar forging](/materials/ams/6414 "SAE AMS 6414") - [6415 Indicative bar forging](/materials/ams/6415 "SAE AMS 6415") - [6417 Indicative bar tube](/materials/ams/6417 "SAE AMS 6417") - [6419 Indicative bar tube](/materials/ams/6419 "SAE AMS 6419") - [6484 Indicative bar forging](/materials/ams/6484 "SAE AMS 6484") GOST Russia / CIS · 2 - [40ChN2MA Indicative](/materials/bds/40chn2ma "GOST 40ChN2MA") - [40KhN2MA Indicative](/materials/gost/40khn2ma "GOST 40KhN2MA") UNI Italy · 2 - [40 NiCrMo 7 Indicative](/materials/uni/40nicrmo7 "UNI 40 NiCrMo 7") - [NCM 4 Indicative](/materials/uni/ncm-4 "UNI NCM 4") PN Poland · 2 - [34HNM Indicative](/materials/pn/34hnm "PN 34HNM") - [40HNMA Indicative](/materials/pn/40hnma "PN 40HNMA") MKE Türkiye · 1 - [Ç 4340 Indicative](/materials/mke/c-4340 "MKE Ç 4340") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 9 elements on file · weight % What this alloy is Fe Ni Cr Mn Iron — the balance, never listed by a standard — 95.5 % Ni — 1.8 % Cr — 0.8 % Mn — 0.8 % Traces & impurities · 1.1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.37–0.44 | | Si | 0.2–0.35 | | Mn | 0.7–0.9 | | P | 0.02 | | S | 0.015 | | Cr | 0.7–0.95 | | Mo | 0.3–0.4 | | Ni | 1.65–2 | | Al | 0.005–0.05 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Aluminium 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 | 0,37-0,44 | 0.370 | 0.440 | Range | | Al | 0,005-0,050 | 0.005 | 0.050 | Range | | Si | 0,20-0,35 | 0.200 | 0.350 | Range | | P | 0,02 | 0.020 | 0.020 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | Cr | 0,70-0,95 | 0.700 | 0.950 | Range | | Mn | 0,70-0,90 | 0.700 | 0.900 | Range | | Ni | 1,65-2,00 | 1.650 | 2.000 | Range | | Mo | 0,30-0,40 | 0.300 | 0.400 | 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 computed from composition · °C Predicted Ae3 741 °C Predicted Ae1 711 °C Predicted Acm 619 °C Predicted Bs 501 °C These four temperatures are a CALCULATION from this grade's own composition, using the published Li, Niebuhr, Meekisho & Atteridge (1998) model — never a measurement, and computed from the UPPER BOUND of each element's specified range, not a mid-range figure. Where this grade also has a measured transformation point (Ac1, Ac3, Ar1, Ar3) on file, it is shown separately, in Physical & mechanical properties, and is never replaced by the predicted figures here — Ae (predicted, equilibrium) and Ac/Ar (measured, on heating or cooling) are different physical quantities and can differ by tens of degrees; a mismatch between the two is not an error in either. ## 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 1.6, a shared category, and a published range for Ni / Cr 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. [38NiCrMoV7-3 1.6926 Ni 1,60-2,00 · Cr 0,65-0,95 - ΔNi 0.02 - ΔCr 0.02 - 1 designations](/materials/din-en/38nicrmov7-3 "38NiCrMoV7-3")[41SiNiCrMoV7-6 1.6928 Ni 1,20-1,70 · Cr 0,60-1,00 - ΔNi 0.38 - ΔCr 0.02 - 7 designations](/materials/din-en/41sinicrmov7-6 "41SiNiCrMoV7-6")[40NiCrMo6 1.6565 Ni 1,40-1,70 · Cr 0,90-1,40 - ΔNi 0.28 - ΔCr 0.32 - 56 designations](/materials/din-en/40nicrmo6 "40NiCrMo6") ## 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=95b93c8a-977b-4b13-8b34-bf4abb4f212b&designation=aeda8507-1240-4449-a3f3-5e7c8d87c82b "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/aisi-sae/e4340-mod.pdf "Datasheet as PDF")