--- title: "4320RH — Case hardening steels" description: "4320RH in AISI / SAE: material number 1.5919, also listed as 17CrNi6-6. Category: Case hardening steels. Designations recorded for this grade: 29." canonical: https://steelequivalents.com/materials/aisi-sae/4320rh language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/aisi-sae/4320rh.md cs: https://steelequivalents.com/cs/materiály/aisi-sae/4320rh.md de: https://steelequivalents.com/de/werkstoffe/aisi-sae/4320rh.md es: https://steelequivalents.com/es/materiales/aisi-sae/4320rh.md fr: https://steelequivalents.com/fr/matériaux/aisi-sae/4320rh.md hu: https://steelequivalents.com/hu/anyagok/aisi-sae/4320rh.md it: https://steelequivalents.com/it/materiali/aisi-sae/4320rh.md nl: https://steelequivalents.com/nl/materialen/aisi-sae/4320rh.md pl: https://steelequivalents.com/pl/materiały/aisi-sae/4320rh.md pt: https://steelequivalents.com/pt/materiais/aisi-sae/4320rh.md ru: https://steelequivalents.com/ru/материалы/aisi-sae/4320rh.md tr: https://steelequivalents.com/tr/malzemeler/aisi-sae/4320rh.md zh: https://steelequivalents.com/zh/材料/aisi-sae/4320rh.md ja: https://steelequivalents.com/ja/材料/aisi-sae/4320rh.md ar: https://steelequivalents.com/ar/المواد/aisi-sae/4320rh.md ko: https://steelequivalents.com/ko/재료/aisi-sae/4320rh.md pt-br: https://steelequivalents.com/pt-br/materiais/aisi-sae/4320rh.md hi: https://steelequivalents.com/hi/सामग्री/aisi-sae/4320rh.md content_hash: sha256:b67d4800ffac7e6df61d1cea2da11694af4cb438bb36c3c1744753baaa7ac4ad 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/4320rh > Canonical URL: https://steelequivalents.com/materials/aisi-sae/4320rh > 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 · 29 designations # 4320RH 4320RH is a designation in AISI / SAE for the material held under material number 1.5919, also listed as 17CrNi6-6. It is a material in the category Case hardening steels. We list 29 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, AFNOR, JIS, GB, GOST, ČSN, PN, COPANT, SRPS and BDS. - [*Material no.* **1.5919**](/materials/material-no/1.5919 "Material no.: 1.5919") - [*Category* **Case hardening steels · 60 grades**](/categories/case-hardening-steels "Category: Case hardening steels · 60 grades") - *Designations* **29** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=19edb9d9-8f84-46f6-9ede-b70bfc881ba5&designation=a4e50ebe-484c-45f9-95ea-e8be8935871d "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/aisi-sae/4320rh.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN 15CrNi6 This grade’s own name · 2 grades on that route](/materials/din-en/15crni6 "DIN / EN 15CrNi6") - [UNS G43200 This grade’s own name](/materials/uns/g43200 "UNS G43200") - [AISI / SAE 4320 This grade’s own name · 2 grades on that route](/materials/aisi-sae/4320 "AISI / SAE 4320") ## About Case hardening steels Case hardening steels are steels designed to develop a hard, wear-resistant surface while retaining a tough and ductile core. They are used for components such as gears, shafts and other machine parts exposed to contact wear and cyclic loading. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 29 designations · 12 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 - [15CrNi6 This grade’s own name](/materials/din-en/15crni6 "DIN / EN 15CrNi6") - [17CrNi6-6 This grade’s own name](/materials/din-en/17crni6-6 "DIN / EN 17CrNi6-6") UNS United States · 4 - [4320 Indicative](/materials/aisi-sae/4320 "UNS 4320") - [G43200 This grade’s own name](/materials/uns/g43200 "UNS G43200") - [G46170 This grade’s own name](/materials/uns/g46170 "UNS G46170") - [H43200 This grade’s own name](/materials/uns/h43200 "UNS H43200") AISI / SAE United States · 5 - [3115 Indicative](/materials/aisi-sae/3115 "AISI / SAE 3115") - [4320 This grade’s own name](/materials/aisi-sae/4320 "AISI / SAE 4320") - [4320H This grade’s own name](/materials/aisi-sae/4320h "AISI / SAE 4320H") - **4320RH This grade’s own name** - [4617 This grade’s own name](/materials/aisi-sae/4617 "AISI / SAE 4617") AFNOR France · 1 - [16NC6 Indicative](/materials/afnor/16nc6 "AFNOR 16NC6") JIS Japan · 2 - [SNCM420 Indicative](/materials/jis/sncm420 "JIS SNCM420") - [SNCM420H Indicative](/materials/jis/sncm420h "JIS SNCM420H") GB China · 4 - [20CrNi3 Indicative](/materials/gb/20crni3 "GB 20CrNi3") - [20CrNi3A Indicative](/materials/gb/20crni3a "GB 20CrNi3A") - [A42202 Indicative](/materials/gb/a42202 "GB A42202") - [A42203 Indicative](/materials/gb/a42203 "GB A42203") GOST Russia / CIS · 2 - [20ChN3A Indicative](/materials/gost/20chn3a "GOST 20ChN3A") - [20KhN3A Indicative](/materials/gost/20khn3a "GOST 20KhN3A") ČSN Czechia · 3 - [16220 Indicative](/materials/csn/16220 "ČSN 16220") - [16321 Indicative](/materials/csn/16321 "ČSN 16321") - [16321 PH Indicative](/materials/csn/16321-ph "ČSN 16321 PH") PN Poland · 2 - [15HN Indicative](/materials/pn/15hn "PN 15HN") - [20HN3A Indicative](/materials/pn/20hn3a "PN 20HN3A") COPANT Latin America · 1 - [4320 Indicative](/materials/aisi-sae/4320 "COPANT 4320") SRPS Serbia · 1 - [Č.5420 Indicative](/materials/srps/c-5420 "SRPS Č.5420") BDS Bulgaria · 2 - [20ChN3A Indicative](/materials/gost/20chn3a "BDS 20ChN3A") - [20KhN3A Indicative](/materials/gost/20khn3a "BDS 20KhN3A") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 10 elements on file · weight % What this alloy is Fe Cr Ni Mn Iron — the balance, never listed by a standard — 95.8 % Cr — 1.5 % Ni — 1.5 % Mn — 0.6 % Traces & impurities · 0.7 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.12–0.18 | | Si | ≤ 0.25 | | Mn | 0.4–0.7 | | P | 0.02 | | S | 0.015 | | Cr | 1.35–1.65 | | Ni | 1.35–1.65 | | Cu | ≤ 0.2 | | Al | 0.025–0.05 | | N | 0.012 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Nickel Copper Aluminium Nitrogen 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 | 0,12-0,18 | 0.120 | 0.180 | Range | | N | 0,012 | 0.012 | 0.012 | Exact | | Al | 0,025-0,050 | 0.025 | 0.050 | Range | | Si | ≤0,25 | — | 0.250 | Max | | P | 0,02 | 0.020 | 0.020 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | Cr | 1,35-1,65 | 1.350 | 1.650 | Range | | Mn | 0,40-0,70 | 0.400 | 0.700 | Range | | Ni | 1,35-1,65 | 1.350 | 1.650 | Range | | Cu | ≤0,20 | — | 0.200 | 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: 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. ## Heat treatment Supply condition - Carburizing - Quenching and Tempering d=25 - Quenching Conditions the standard permits on delivery. No temperature or medium is published for these, so no order and no alternation is implied. Source: [www.caishuku.com](https://www.caishuku.com/detail/azhlNWIxMTk3NDA_ "Source: www.caishuku.com") ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.5, a shared category, and a published range for Cr / 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. [15CrNi6 1.5918 Cr 1,40-1,70 · Ni 1,40-1,70 - ΔCr 0.05 - ΔNi 0.05 - 5 designations](/materials/din-en/15crni6 "15CrNi6") ## 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=19edb9d9-8f84-46f6-9ede-b70bfc881ba5&designation=a4e50ebe-484c-45f9-95ea-e8be8935871d "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/aisi-sae/4320rh.pdf "Datasheet as PDF")