--- title: "EN31 — Bearing steels" description: "EN31 in BS: material number 1.3505, also listed as 100Cr6. It is a material in the category Bearing steels. Designations recorded for this grade: 61." canonical: https://steelequivalents.com/materials/bs/en31 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/bs/en31.md cs: https://steelequivalents.com/cs/materiály/bs/en31.md de: https://steelequivalents.com/de/werkstoffe/bs/en31.md es: https://steelequivalents.com/es/materiales/bs/en31.md fr: https://steelequivalents.com/fr/matériaux/bs/en31.md hu: https://steelequivalents.com/hu/anyagok/bs/en31.md it: https://steelequivalents.com/it/materiali/bs/en31.md nl: https://steelequivalents.com/nl/materialen/bs/en31.md pl: https://steelequivalents.com/pl/materiały/bs/en31.md pt: https://steelequivalents.com/pt/materiais/bs/en31.md ru: https://steelequivalents.com/ru/материалы/bs/en31.md tr: https://steelequivalents.com/tr/malzemeler/bs/en31.md zh: https://steelequivalents.com/zh/材料/bs/en31.md ja: https://steelequivalents.com/ja/材料/bs/en31.md ar: https://steelequivalents.com/ar/المواد/bs/en31.md ko: https://steelequivalents.com/ko/재료/bs/en31.md pt-br: https://steelequivalents.com/pt-br/materiais/bs/en31.md hi: https://steelequivalents.com/hi/सामग्री/bs/en31.md content_hash: sha256:3aa340f681d514e63019de5c36e3d74e4b46bf898eac4647d5d688683095e57f generated: 2026-09-22 --- > **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/bs/en31 > Canonical URL: https://steelequivalents.com/materials/bs/en31 > 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. BS · United Kingdom · 61 designations # EN31 EN31 is a designation in BS for the material held under material number 1.3505, also listed as 100Cr6. It is a material in the category Bearing steels. We list 61 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ASTM, BS, AFNOR, UNE, ISO, SAE AMS, JIS, GB, GOST, UNI, SS, ČSN, STN, COPANT, PN, MSZ, AS / NZS, STAS, BDS and KS. - [*Material no.* **1.3505**](/materials/material-no/1.3505 "Material no.: 1.3505") - [*Category* **Bearing steels · 17 grades**](/categories/bearing-steels "Category: Bearing steels · 17 grades") - *Designations* **61** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=f89daac1-83f9-4eff-942d-c4275dbcf35f&designation=0f25e7f9-c064-420e-9048-1508a9311987 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/bs/en31.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN 100Cr6 This grade’s own name · 2 grades on that route](/materials/din-en/100cr6 "DIN / EN 100Cr6") - [UNS J19965 This grade’s own name · 2 grades on that route](/materials/uns/j19965 "UNS J19965") - [BS 535A99 This grade’s own name · 3 grades on that route](/materials/bs/535a99 "BS 535A99") - [GOST SchCh15 This grade’s own name](/materials/gost/schch15 "GOST SchCh15") ## About Bearing steels Bearing steels are high-carbon steels designed for rolling-element bearings and other components exposed to repeated contact loading. They are characterised by high hardness, wear resistance and resistance to rolling-contact fatigue after suitable heat treatment. They are used for bearing rings, races and rolling elements where reliable operation under cyclic loads is required. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 61 designations · 23 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 - [1.3505 Indicative](/materials/material-no/1.3505 "DIN / EN 1.3505") - [100Cr6 This grade’s own name](/materials/din-en/100cr6 "DIN / EN 100Cr6") UNS United States · 7 - [AMS 6440 Indicative](/materials/uns/ams-6440 "UNS AMS 6440") - [G52985 Indicative](/materials/uns/g52985 "UNS G52985") - [G52986 Indicative](/materials/uns/g52986 "UNS G52986") - [G52986 / G52950 Indicative](/materials/uns/g52986-g52950 "UNS G52986 / G52950") - [J19965 This grade’s own name](/materials/uns/j19965 "UNS J19965") - [K23080 Indicative](/materials/uns/k23080 "UNS K23080") - [S-22141 Indicative](/materials/uns/s-22141 "UNS S-22141") AISI / SAE United States · 5 - [52100 Indicative](/materials/aisi-sae/52100 "AISI / SAE 52100") - [ASTM 52100 Indicative](/materials/aisi-sae/astm-52100 "AISI / SAE ASTM 52100") - [E52100 Indicative](/materials/aisi-sae/e52100 "AISI / SAE E52100") - [G52986 Indicative](/materials/uns/g52986 "AISI / SAE G52986") - [J19965 Indicative](/materials/uns/j19965 "AISI / SAE J19965") ASTM United States · 1 - [A646 Indicative](/materials/astm/a646 "ASTM A646") BS United Kingdom · 5 - [2S135 Indicative](/materials/bs/2s135 "BS 2S135") - [534A99 Indicative](/materials/bs/534a99 "BS 534A99") - [535A99 This grade’s own name](/materials/bs/535a99 "BS 535A99") - **EN31 Indicative** - [S135 Indicative](/materials/bs/s135 "BS S135") AFNOR France · 3 - [100C6 Indicative](/materials/afnor/100c6 "AFNOR 100C6") - [100Cr6 Indicative](/materials/din-en/100cr6 "AFNOR 100Cr6") - [100Cr6RR Indicative](/materials/afnor/100cr6rr "AFNOR 100Cr6RR") UNE Spain · 5 - [100 Indicative](/materials/bs/100 "UNE 100") - [100Cr6 Indicative](/materials/din-en/100cr6 "UNE 100Cr6") - [Cr6 Indicative](/materials/une/cr6 "UNE Cr6") - [F.131 Indicative](/materials/une/f-131 "UNE F.131") - [F.1310 Indicative](/materials/une/f-1310 "UNE F.1310") ISO International · 2 - [100Cr6 Indicative](/materials/din-en/100cr6 "ISO 100Cr6") - [3505 Indicative](/materials/iso/3505 "ISO 3505") SAE AMS United States / Aerospace · 2 - [6440 Indicative bar](/materials/ams/6440 "SAE AMS 6440") - [6444 Indicative bar](/materials/ams/6444 "SAE AMS 6444") JIS Japan · 2 - [SUJ2 Indicative](/materials/jis/suj2 "JIS SUJ2") - [SUJ4 Indicative](/materials/jis/suj4 "JIS SUJ4") GB China · 4 - [45G Indicative](/materials/gost/45g "GB 45G") - [Cr2 Indicative](/materials/is/cr2 "GB Cr2") - [GCr15 Indicative](/materials/gb/gcr15 "GB GCr15") - [Gr15 Indicative](/materials/gb/gr15 "GB Gr15") GOST Russia / CIS · 7 - [Šch15 Indicative](/materials/jis/sch15 "GOST Šch15") - [SchCh15 This grade’s own name](/materials/gost/schch15 "GOST SchCh15") - [ShCh15 Indicative](/materials/gost/shch15 "GOST ShCh15") - [SHKH15 Indicative](/materials/gost/shkh15 "GOST SHKH15") - [ШХ15 Indicative](/materials/gost/shkh15 "GOST ШХ15") - [ШХ15-В Indicative](/materials/gost/shkh15-v "GOST ШХ15-В") - [ШХ15-Ш Indicative](/materials/gost/shkh15-sh "GOST ШХ15-Ш") UNI Italy · 1 - [100Cr6 Indicative](/materials/din-en/100cr6 "UNI 100Cr6") SS Sweden · 1 - [2258 Indicative](/materials/ss/2258 "SS 2258") ČSN Czechia · 2 - [14100 Indicative](/materials/csn/14100 "ČSN 14100") - [14109 Indicative](/materials/csn/14109 "ČSN 14109") STN Slovakia · 1 - [14 109 Indicative](/materials/csn/14109 "STN 14 109") COPANT Latin America · 1 - [52100 Indicative](/materials/aisi-sae/52100 "COPANT 52100") PN Poland · 3 - [LH15 Indicative](/materials/pn/lh15 "PN LH15") - [ŁH15 Indicative](/materials/pn/lh15 "PN ŁH15") - [NC4 Indicative](/materials/pn/nc4 "PN NC4") MSZ Hungary · 1 - [GO3 Indicative](/materials/msz/go3 "MSZ GO3") AS / NZS Australia / New Zealand · 1 - [5210 Indicative](/materials/as-nzs/5210 "AS / NZS 5210") STAS Romania · 2 - [RUL1 Indicative](/materials/stas/rul1 "STAS RUL1") - [RUL1v Indicative](/materials/stas/rul1v "STAS RUL1v") BDS Bulgaria · 1 - [SchCh15 Indicative](/materials/gost/schch15 "BDS SchCh15") KS South Korea · 2 - [STB2 Indicative](/materials/ks/stb2 "KS STB2") - [STB4 Indicative](/materials/ks/stb4 "KS STB4") 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 C Mn Iron — the balance, never listed by a standard — 96.4 % Cr — 1.5 % C — 1 % Mn — 0.4 % Traces & impurities · 0.7 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.93–1.05 | | Si | 0.15–0.35 | | Mn | 0.25–0.45 | | P | 0.025 | | S | 0.015 | | Cr | 1.35–1.6 | | Mo | ≤ 0.1 | | Cu | ≤ 0.3 | | Al | ≤ 0.05 | | O | ≤ 0.0015 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Copper Aluminium Oxygen 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 | 0,93-1,05 | 0.930 | 1.050 | Range | | O | ≤0,0015 | — | 0.002 | Max | | Al | ≤0,050 | — | 0.050 | Max | | Si | 0,15-0,35 | 0.150 | 0.350 | Range | | P | 0,025 | 0.025 | 0.025 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | Cr | 1,35-1,60 | 1.350 | 1.600 | Range | | Mn | 0,25-0,45 | 0.250 | 0.450 | Range | | Cu | ≤0,30 | — | 0.300 | Max | | Mo | ≤0,10 | — | 0.100 | 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. ## Physical & mechanical properties Density 7,8 g/cm³ Exact Transformation point Ac1 715 °C Exact Transformation point Ac3 735 °C Exact · Ac3(Acm) Transformation point Ar3 710 °C Exact · Ar3(Arcm) Transformation point Ar1 635 °C Exact Weldability difficult to weld As published: hard weldability. Temper brittleness slightly susceptible As published: weakly predisposed 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 2 conditions · 6 values By dimension**Quenching 850°C, oil, Drawing 600°C, air** source `splav` | Dimension mm | Rm N/mm² | Re N/mm² | A5% | Z% | KCU kJ/m² | |---|---|---|---|---|---| | Ø 25 | 620 | 370 | 15 | 40 | 490 | By delivery state**no delivery state stated** source `splav` | Delivery state | HB | |---|---| | (annealing) , GOST 4543-71 | 229 | 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 **GB /T 1299-2025** Single operation Test specimen - Quenching 830–860 °C Cooling Oil Supply condition - Quenching Test specimen - Annealing Supply condition - Spheroidize annealing - Annealing 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/azhlNWIxMTk1MDU_ "Source: www.caishuku.com") ## 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=f89daac1-83f9-4eff-942d-c4275dbcf35f&designation=0f25e7f9-c064-420e-9048-1508a9311987 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/bs/en31.pdf "Datasheet as PDF")