--- title: "K23745 — Nitriding steels" description: "K23745 in UNS: material number 1.8506, also listed as 34CrAlS5. It is a material in the category Nitriding steels. 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Compare it to detect a real > content change; `generated` moves on every render and is not a change signal. UNS · United States · 2 designations # K23745 K23745 is a designation in UNS for the material held under material number 1.8506, also listed as 34CrAlS5. It is a material in the category Nitriding steels. We list 2 designations recorded for this grade, in the standards DIN / EN and UNS. - [*Material no.* **1.8506**](/materials/material-no/1.8506 "Material no.: 1.8506") - [*Category* **Nitriding steels · 11 grades**](/categories/nitriding-steels "Category: Nitriding steels · 11 grades") - *Designations* **2** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=5e9456ec-2e97-4a70-9d95-d600987845da&designation=14f7aca2-5810-4977-b585-135fcd9f0fb4 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/uns/k23745.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN 34CrAlS5 This grade’s own name](/materials/din-en/34crals5 "DIN / EN 34CrAlS5") ## About Nitriding steels Nitriding steels are alloy steels designed for nitriding, a surface-hardening treatment that produces a hard, wear-resistant surface while retaining a tough supporting core. They are used for gears, shafts, dies and other components requiring resistance to wear, repeated loading and dimensional change in service. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 2 designations · 2 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 Withdrawn designation no longer current — a separate column from the two above, so a name can be same grade and withdrawn at once.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 · 1 - [34CrAlS5 This grade’s own name](/materials/din-en/34crals5 "DIN / EN 34CrAlS5") UNS United States · 1 - **K23745 This grade’s own name** Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 7 elements on file · weight % What this alloy is Fe Cr Al Mn Iron — the balance, never listed by a standard — 96.3 % Cr — 1.2 % Al — 1 % Mn — 0.8 % Traces & impurities · 0.8 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.3–0.37 | | Si | 0.15–0.4 | | Mn | 0.6–0.9 | | P | 0.1 — Unusual | | S | 0.07–0.11 — Unusual | | Cr | 1–1.3 | | Al | 0.8–1.2 | Carbon Silicon Manganese Phosphorus Sulfur Chromium 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 | 0,30-0,37 | 0.300 | 0.370 | Range | | Al | 0,80-1,20 | 0.800 | 1.200 | Range | | Si | 0,15-0,40 | 0.150 | 0.400 | Range | | P | 0,1 | 0.100 | 0.100 | Exact | | S | 0,07-0,11 | 0.070 | 0.110 | Range | | Cr | 1,00-1,30 | 1.000 | 1.300 | Range | | Mn | 0,60-0,90 | 0.600 | 0.900 | 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, 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 1.8, a shared category, and a published range for Cr / Al 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. [34CrAlMo5-10 1.8507 Cr 1,00-1,30 · Al 0,80-1,20 - ΔCr 0.00 - ΔAl 0.00 - 14 designations](/materials/din-en/34cralmo5-10 "34CrAlMo5-10")[34CrAl6 1.8504 Cr 1,20-1,50 · Al 0,80-1,10 - ΔCr 0.20 - ΔAl 0.05 - 2 designations](/materials/din-en/34cral6 "34CrAl6") ## 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=5e9456ec-2e97-4a70-9d95-d600987845da&designation=14f7aca2-5810-4977-b585-135fcd9f0fb4 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/uns/k23745.pdf "Datasheet as PDF")