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.
If you came for one of these
The most-used names for this grade.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 hiddenEvery 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
Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade.
| Element | % by weight |
|---|---|
0.37–0.44 | |
0.2–0.35 | |
0.7–0.9 | |
0.02 | |
0.015 | |
0.7–0.95 | |
0.3–0.4 | |
1.65–2 | |
0.005–0.05 |
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 publishedsource 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 · °CThese 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
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.
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.