203-4
203-4 is a designation in BS for the material held under material number 2.4630, also listed as NiCr20Ti. It is a material in the category High-temperature steels / aviation variant. We list 10 designations recorded for this grade, in the standards DIN / EN, UNS, BS and AFNOR.
If you came for one of these
The most-used names for this grade.About High-temperature steels / aviation variant
High-temperature aviation steels are heat-resistant materials designed to retain strength and structural stability during prolonged exposure to elevated temperatures. Their alloying provides resistance to creep, oxidation, and thermal degradation, making them suitable for aircraft engine and other hot-section components.
This describes the material class as a whole. Always confirm the individual grade against the standard before ordering.
Also known as
10 designations · 4 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
12 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 |
|---|---|
0.08–0.15 | |
≤ 1 | |
≤ 1 | |
0.03 | |
0.02 | |
18–21 | |
Balance | |
≤ 5 | |
≤ 0.5 | |
0.2–0.6 | |
≤ 0.005 | |
≤ 5 |
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 | 0,08-0,15 | 0.080 | 0.150 | Range |
| Si | ≤1,00 | — | 1.000 | Max |
| P | 0,03 | 0.030 | 0.030 | Exact |
| S | 0,02 | 0.020 | 0.020 | Exact |
| Ti | 0,20-0,60 | 0.200 | 0.600 | Range |
| Cr | 18,0-21,0 | 18.000 | 21.000 | Range |
| Mn | ≤1,00 | — | 1.000 | Max |
| Fe | ≤5,00 | — | 5.000 | Max |
| Co | ≤5,00 | — | 5.000 | Max |
| Ni | Rest/Bal. | 65.695 | 81.670 | Balance |
| Cu | ≤0,50 | — | 0.500 | Max |
| Pb | ≤0,005 | — | 0.005 | 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
Not enough recorded composition to predict a transformation temperature for this grade — missing: Ni, Mo.
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.
Properties by condition
1 conditions · 1 valuessteelnumber| Delivery state | HB |
|---|---|
| Solution annealed | 230 |
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 2.4, 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.