--- title: "1.6523 — Case hardening steels" description: "1.6523 is the material number of the grade also listed as 20NiCrMo2-2. Category: Case hardening steels. Designations recorded for this grade: 63." canonical: https://steelequivalents.com/materials/material-no/1.6523 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/material-no/1.6523.md cs: https://steelequivalents.com/cs/materiály/číslo-materiálu/1.6523.md de: https://steelequivalents.com/de/werkstoffe/werkstoff-nr/1.6523.md es: https://steelequivalents.com/es/materiales/número-de-material/1.6523.md fr: https://steelequivalents.com/fr/matériaux/numéro-de-matériau/1.6523.md hu: https://steelequivalents.com/hu/anyagok/anyagszám/1.6523.md it: https://steelequivalents.com/it/materiali/numero-materiale/1.6523.md nl: https://steelequivalents.com/nl/materialen/materiaalnummer/1.6523.md pl: https://steelequivalents.com/pl/materiały/numer-materiału/1.6523.md pt: https://steelequivalents.com/pt/materiais/número-do-material/1.6523.md ru: https://steelequivalents.com/ru/материалы/номер-материала/1.6523.md tr: https://steelequivalents.com/tr/malzemeler/malzeme-numarası/1.6523.md zh: https://steelequivalents.com/zh/材料/材料编号/1.6523.md ja: https://steelequivalents.com/ja/材料/材料番号/1.6523.md ar: https://steelequivalents.com/ar/المواد/رقم-المادة/1.6523.md ko: https://steelequivalents.com/ko/재료/재료번호/1.6523.md pt-br: https://steelequivalents.com/pt-br/materiais/número-do-material/1.6523.md hi: https://steelequivalents.com/hi/सामग्री/सामग्री-संख्या/1.6523.md content_hash: sha256:7c5296bb23e485d3b3a4df2af9d492b495c96b85db143472144970268d3eeef8 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/material-no/1.6523 > Canonical URL: https://steelequivalents.com/materials/material-no/1.6523 > 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. Material number · Europe · 63 designations # 1.6523 1.6523 is the material number of the grade also listed as 20NiCrMo2-2. It is a material in the category Case hardening steels. We list 63 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, BS, AFNOR, UNE, ISO, JIS, GB, GOST, UNI, SS, ČSN, PN, COPANT, SRPS, AS / NZS, SFS and KS. - ***Material no.* **1.6523**** - [*Category* **Case hardening steels · 60 grades**](/categories/case-hardening-steels "Category: Case hardening steels · 60 grades") - *Designations* **63** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=46bfb13a-e831-4c1e-b982-919a85b20e77 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/material-no/1.6523.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN 20NiCrMo2-2 This grade’s own name](/materials/din-en/20nicrmo2-2 "DIN / EN 20NiCrMo2-2") - [UNS G86170 This grade’s own name](/materials/uns/g86170 "UNS G86170") - [AISI / SAE 8617 This grade’s own name](/materials/aisi-sae/8617 "AISI / SAE 8617") ## 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 63 designations · 19 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 · 3 - **1.6523 Indicative** - [20NiCrMo2-2 This grade’s own name](/materials/din-en/20nicrmo2-2 "DIN / EN 20NiCrMo2-2") - [21NiCrMo2 This grade’s own name Withdrawn](/materials/din-en/21nicrmo2 "DIN / EN 21NiCrMo2") UNS United States · 5 - [G86170 This grade’s own name](/materials/uns/g86170 "UNS G86170") - [G86200 This grade’s own name](/materials/uns/g86200 "UNS G86200") - [H86170 This grade’s own name](/materials/uns/h86170 "UNS H86170") - [H86200 This grade’s own name](/materials/uns/h86200 "UNS H86200") - [K12147 This grade’s own name](/materials/uns/k12147 "UNS K12147") AISI / SAE United States · 15 - [8615 8617 8620 8622 Indicative](/materials/aisi-sae/8615-8617-8620-8622 "AISI / SAE 8615 8617 8620 8622") - [8617 This grade’s own name](/materials/aisi-sae/8617 "AISI / SAE 8617") - [8617H This grade’s own name](/materials/aisi-sae/8617h "AISI / SAE 8617H") - [8620 This grade’s own name](/materials/aisi-sae/8620 "AISI / SAE 8620") - [8620H This grade’s own name](/materials/aisi-sae/8620h "AISI / SAE 8620H") - [8620RH This grade’s own name](/materials/aisi-sae/8620rh "AISI / SAE 8620RH") - [8622H Indicative](/materials/aisi-sae/8622h "AISI / SAE 8622H") - [8717 This grade’s own name](/materials/aisi-sae/8717 "AISI / SAE 8717") - [EX5 This grade’s own name](/materials/aisi-sae/ex5 "AISI / SAE EX5") - [G86170 Indicative](/materials/uns/g86170 "AISI / SAE G86170") - [G86200 Indicative](/materials/uns/g86200 "AISI / SAE G86200") - [H86170 Indicative](/materials/uns/h86170 "AISI / SAE H86170") - [H86200 Indicative](/materials/uns/h86200 "AISI / SAE H86200") - [J11442 Indicative](/materials/aisi-sae/j11442 "AISI / SAE J11442") - [K12147 Indicative](/materials/uns/k12147 "AISI / SAE K12147") BS United Kingdom · 9 - [20NiCrMo2-2 Indicative](/materials/din-en/20nicrmo2-2 "BS 20NiCrMo2-2") - [20NiCrMoS2-2 Indicative](/materials/din-en/20nicrmos2-2 "BS 20NiCrMoS2-2") - [362 Indicative](/materials/bs/362 "BS 362") - [805H17 Indicative](/materials/bs/805h17 "BS 805H17") - [805H20 Indicative](/materials/bs/805h20 "BS 805H20") - [805H22 Indicative](/materials/bs/805h22 "BS 805H22") - [805M20 Indicative](/materials/bs/805m20 "BS 805M20") - [806M20 Indicative](/materials/bs/806m20 "BS 806M20") - [EN362 Indicative](/materials/bs/en362 "BS EN362") AFNOR France · 3 - [20NCD2 Indicative](/materials/afnor/20ncd2 "AFNOR 20NCD2") - [20NiCrMo2 Indicative](/materials/din-en/20nicrmo2 "AFNOR 20NiCrMo2") - [22NCD2 Indicative](/materials/afnor/22ncd2 "AFNOR 22NCD2") UNE Spain · 3 - [20NiCrMo2 Indicative](/materials/din-en/20nicrmo2 "UNE 20NiCrMo2") - [20NiCrMo2-2 Indicative](/materials/din-en/20nicrmo2-2 "UNE 20NiCrMo2-2") - [20NiCrMo3-1 Indicative](/materials/une/20nicrmo3-1 "UNE 20NiCrMo3-1") ISO International · 2 - [20NiCrMo2 Indicative](/materials/din-en/20nicrmo2 "ISO 20NiCrMo2") - [20NiCrMoS2 Indicative](/materials/iso/20nicrmos2 "ISO 20NiCrMoS2") JIS Japan · 2 - [SNCM220 Indicative](/materials/ks/sncm220 "JIS SNCM220") - [SNCM220H Indicative](/materials/ks/sncm220h "JIS SNCM220H") GB China · 3 - [20CrNiMo Indicative](/materials/gb/20crnimo "GB 20CrNiMo") - [20CrNiMoH Indicative](/materials/gb/20crnimoh "GB 20CrNiMoH") - [G20CrNiMo Indicative](/materials/gb/g20crnimo "GB G20CrNiMo") GOST Russia / CIS · 2 - [20KHGNM Indicative](/materials/gost/20khgnm "GOST 20KHGNM") - [20ХГНМ Indicative](/materials/gost/20khgnm "GOST 20ХГНМ") UNI Italy · 1 - [20NiCrMo2 Indicative](/materials/din-en/20nicrmo2 "UNI 20NiCrMo2") SS Sweden · 1 - [2506 Indicative](/materials/ss/2506 "SS 2506") ČSN Czechia · 2 - [16 125 PH Indicative](/materials/csn/16125ph "ČSN 16 125 PH") - [16125 Indicative](/materials/csn/16125 "ČSN 16125") PN Poland · 2 - [20HNM Indicative](/materials/pn/20hnm "PN 20HNM") - [20HNMA Indicative](/materials/pn/20hnma "PN 20HNMA") COPANT Latin America · 1 - [8620 Indicative](/materials/aisi-sae/8620 "COPANT 8620") SRPS Serbia · 1 - [Č.7422 Indicative](/materials/srps/c-7422 "SRPS Č.7422") AS / NZS Australia / New Zealand · 4 - [8617 Indicative](/materials/aisi-sae/8617 "AS / NZS 8617") - [8617H Indicative](/materials/aisi-sae/8617h "AS / NZS 8617H") - [8620 Indicative](/materials/aisi-sae/8620 "AS / NZS 8620") - [8620H Indicative](/materials/aisi-sae/8620h "AS / NZS 8620H") SFS Finland · 2 - [21NiCrMo2 Indicative](/materials/din-en/21nicrmo2 "SFS 21NiCrMo2") - [506 Indicative](/materials/sfs/506 "SFS 506") KS South Korea · 2 - [SNCM220 Indicative](/materials/ks/sncm220 "KS SNCM220") - [SNCM220H Indicative](/materials/ks/sncm220h "KS SNCM220H") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 8 elements on file · weight % What this alloy is Fe Mn Ni Cr Iron — the balance, never listed by a standard — 97.3 % Mn — 0.8 % Ni — 0.6 % Cr — 0.5 % Traces & impurities · 0.9 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.17–0.23 | | Si | ≤ 0.4 | | Mn | 0.65–0.95 | | P | 0.025 | | S | 0.035 | | Cr | 0.35–0.7 | | Mo | 0.15–0.25 | | Ni | 0.4–0.7 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel 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 | 0,17-0,23 | 0.170 | 0.230 | Range | | Si | ≤0,40 | — | 0.400 | Max | | P | 0,025 | 0.025 | 0.025 | Exact | | S | 0,035 | 0.035 | 0.035 | Exact | | Cr | 0,35-0,70 | 0.350 | 0.700 | Range | | Mn | 0,65-0,95 | 0.650 | 0.950 | Range | | Ni | 0,40-0,70 | 0.400 | 0.700 | Range | | Mo | 0,15-0,25 | 0.150 | 0.250 | 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 · °C Predicted Ae3 804 °C Predicted Ae1 725 °C Predicted Acm 471 °C Predicted Bs 546 °C These 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 Density 7,75 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. ## Properties by condition 5 conditions · 8 values By heat-treated condition**no delivery state stated** source `splav` | Heat-treated condition | Rm N/mm² | Re N/mm² | A5% | KCU kJ/m² | |---|---|---|---|---| | , GOST 4543-71 | 1180 – 1570 | 930 | 7 | 590 | By delivery state**Soft annealed** source `steelnumber` | Delivery state | HB | |---|---| | Soft annealed | 212 | By delivery state**Treated to hardness range** source `steelnumber` | Delivery state | HB | |---|---| | Treated to hardness range | 161 – 212 | By delivery state**Treated to ferrite-pearlite structure and hardness range** source `steelnumber` | Delivery state | HB | |---|---| | Treated to ferrite-pearlite structure and hardness range | 149 – 194 | At temperature**no delivery state stated** source `steelnumber` | Temperature °C | Rm N/mm² | |---|---| | 200 | 1100 | 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. ## Heat treatment Supply condition - Carburizing - Quenching and Tempering d=15 - Quenching - Annealing or Tempering 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/azhlNWIxMTM5MTI_ "Source: www.caishuku.com") ## 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. [20NiCrMoS2-2 1.6526 Mn 0,65-0,95 · Ni 0,40-0,70 - ΔMn 0.00 - ΔNi 0.00 - 19 designations](/materials/din-en/20nicrmos2-2 "20NiCrMoS2-2")[21 NiCrMo 2 2 1.6543 Mn 0,70-0,90 · Ni 0,40-0,70 - ΔMn 0.00 - ΔNi 0.00 - 18 designations](/materials/din-en/21-nicrmo-2-2 "21 NiCrMo 2 2")[20MnNiCrMo3-2 1.6522 Mn 0,70-1,00 · Ni 0,40-0,70 - ΔMn 0.05 - ΔNi 0.00 - 14 designations](/materials/din-en/20mnnicrmo3-2 "20MnNiCrMo3-2")[20NiCrMo3 1.6527 Mn 0,70-1,00 · Ni 0,70-0,90 - ΔMn 0.05 - ΔNi 0.25 - 1 designations](/materials/din-en/20nicrmo3 "20NiCrMo3") ## 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=46bfb13a-e831-4c1e-b982-919a85b20e77 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/material-no/1.6523.pdf "Datasheet as PDF")