1.6308
1.6308 is the material number of the grade also listed as 18MnMoNi5-5. It is a material in the category Heat-resistant structural steels. We list 3 designations recorded for this grade, in the standards DIN / EN and UNS.
- Material no. 1.6308
- Category Heat-resistant structural steels · 62 grades
- Designations 3
If you came for one of these
The most-used names for this grade.About Heat-resistant structural steels
Heat-resistant structural steels are structural steels designed to retain useful strength and dimensional stability at elevated temperatures. They are used for load-bearing components in hot-service equipment where mechanical performance must be maintained during heating.
This describes the material class as a whole. Always confirm the individual grade against the standard before ordering.
Also known as
3 designations · 2 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
11 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 |
|---|---|
≤ 0.2 | |
≤ 0.4 | |
1.15–1.55 | |
0.025 | |
0.015 | |
≤ 0.3 | |
0.45–0.55 | |
0.5–0.8 | |
≤ 0.03 | |
≤ 0.3 | |
≤ 0.01 |
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 | ≤0,20 | — | 0.200 | Max |
| Si | ≤0,40 | — | 0.400 | Max |
| P | 0,025 | 0.025 | 0.025 | Exact |
| S | 0,015 | 0.015 | 0.015 | Exact |
| V | ≤0,03 | — | 0.030 | Max |
| Cr | ≤0,30 | — | 0.300 | Max |
| Mn | 1,15-1,55 | 1.150 | 1.550 | Range |
| Ni | 0,50-0,80 | 0.500 | 0.800 | Range |
| Cu | ≤0,30 | — | 0.300 | Max |
| Nb | ≤0,01 | — | 0.010 | Max |
| Mo | 0,45-0,55 | 0.450 | 0.550 | 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 Mn / Ni 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.