20Ch
20Ch is a designation in BDS for the material held under material number 1.7027, also listed as 20Cr4. It is a material in the category Case hardening steels. We list 25 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, BS, AFNOR, ISO, JIS, GB, GOST, PN, SRPS, MSZ and BDS.
If you came for one of these
The most-used names for this grade.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
25 designations · 13 standards · nothing hidden- 20ChIndicative
- 20KHIndicative
- 20XIndicative
- 20ХIndicative
- ст.20XIndicative
- 20ChIndicative
Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here.
Chemical composition
9 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 |
|---|---|
0.17–0.23 | |
≤ 0.4 | |
0.6–0.9 | |
0.025 | |
0.015 | |
0.9–1.2 | |
≤ 0.3 | |
≤ 0.05 | |
≤ 0.002 |
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 | 0,17-0,23 | 0.170 | 0.230 | Range |
| O | ≤0,0020 | — | 0.002 | Max |
| Al | ≤0,05 | — | 0.050 | Max |
| Si | ≤0,40 | — | 0.400 | Max |
| P | 0,025 | 0.025 | 0.025 | Exact |
| S | 0,015 | 0.015 | 0.015 | Exact |
| Cr | 0,90-1,20 | 0.900 | 1.200 | Range |
| Mn | 0,60-0,90 | 0.600 | 0.900 | Range |
| Cu | ≤0,30 | — | 0.300 | 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
3 conditions · 47 valuessplav| Delivery state | RmN/mm² | A5% | HB |
|---|---|---|---|
| Pipe, GOST 8731-87 | 431 | 16 | — |
| (annealing) , GOST 4543-71 | — | — | 179 |
| (cold-worked) , GOST 4543-71 | — | — | 229 |
| Bar GOST 10702-78 | — | — | 163 |
splav| Dimensionmm | RmN/mm² | ReN/mm² | A5% | Z% | KCUkJ/m² |
|---|---|---|---|---|---|
| Ø 15 | 780 | 635 | 11 | 40 | 590 |
splav| Temperature°C | Densityg/cm³ | Elastic modulusGPa | Thermal expansion coefficient10^-6/K | Thermal conductivityW/(m·K) | Specific heat capacityJ/(kg·K) |
|---|---|---|---|---|---|
| 20 | 7.83 | 216 | — | 42 | — |
| 100 | 7.81 | 213 | 10.5 | 42 | 496 |
| 200 | 7.78 | 198 | 11.6 | 41 | 508 |
| 300 | — | 193 | 12.4 | 40 | 525 |
| 400 | 7.71 | 181 | 13.1 | 38 | 537 |
| 500 | — | 171 | 13.6 | 36 | 567 |
| 600 | 7.64 | 165 | 14 | 33 | 588 |
| 700 | — | 143 | — | 32 | 626 |
| 800 | — | 133 | — | 31 | 706 |
4 further values are held for this grade under a condition the source did not name — a bound with no quantity attached. They are withheld rather than shown against a guessed condition.
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
GJB 1220
- Quenching880 °C
- Quenching780–820 °CQuenchant Water or Oil
- Tempering200 °CCooling Water or Air
Supply condition
- Soft annealingAll product forms
- Spheroidize annealing
- Solution annealing
- Soft annealingBar and Wire rod
- Soft annealingAll product forms
- Soft annealing16<t≤100
- Quenching and temperingd≤100
- Normalizing and Temperingd≤100
- Carburizing
- Quenching and Temperingd=15
- Quenching
- Annealing and Tempering and NormalizingSupply condition
- Spheroidize annealingPlate and Strip
- Annealing or TemperingSteel product
- Quenching and TemperingTest specimen30
- Carburizing and Quenching and Tempering≤60
- Quenching and TemperingTest specimen15
- 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
Similar grades — and why
Selection rule, stated so you can disagree with it: same number class 1.7, a shared category, and a published range for Cr / Mn 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.
Cr 0,90-1,20 · Mn 0,60-0,90
- ΔCr 0.00
- ΔMn 0.00
- 1 designations
Cr 0,90-1,20 · Mn 0,60-0,90
- ΔCr 0.00
- ΔMn 0.00
- 7 designations
Cr 0,90-1,20 · Mn 0,60-0,90
- ΔCr 0.00
- ΔMn 0.00
- 23 designations
Cr 0,90-1,20 · Mn 0,60-0,90
- ΔCr 0.00
- ΔMn 0.00
- 3 designations
Cr 0,70-1,00 · Mn 0,60-0,90
- ΔCr 0.20
- ΔMn 0.00
- 2 designations
Cr 0,70-1,00 · Mn 0,60-0,90
- ΔCr 0.20
- ΔMn 0.00
- 36 designations
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.