Compare steel SCM440H and SCM440

24/09/2021

On the market, besides the SCM440 steel label, there also appears the SCM440H steel line that is rated as superior in terms of quality. So exactly 2 different steel grades in this difference? Let's also compare SCM440H and SCM440 solid steel with Sevit right below.

When mentioning SCM440 steel, everyone will know it because of its popularity in mechanical engineering. However, on the market today, besides the SCM440 steel grade, there is also the SCM440H steel line.
So, there are some similarities and differences between them. Please also compare SCM440H and SCM440 solid steel in the following article.
1. SCM440 and SCM440H steel profile
a. SCM440 steel
- The material is manufactured according to JIS G 4053 standards of Japan.
- SCM440 steel is Cr - Mo steel with resistance to oxidation corrosion and especially in salty environment, good heat resistance, very good tensile strength. SCM440 steel is often used to make gears, pump shafts and machine parts in the oil and gas, marine industries, ...

Comparison of solid steel SCM440H and SCM440
b. Steel SCM440H
- Is a steel grade produced according to JIS G 4052 standards of Japan.
- SCM440H steel has a special round shape suitable for use as machine parts under load, impact and abrasion.
2. Compare SCM440H and SCM440 solid steel for chemical composition

Stt	Thành phần hóa học	SCM440 (%)	SCM440H (%)
1	Cacbon	0,38 – 0,43	0,37 – 0,44
2	Silic	0,15 – 0,35	0,15 – 0,35
3	Mangan	0,6 – 0,85	0,55 – 0,9
4	Photpho	≤ 0,03	≤ 0,03
5	Lưu huỳnh	≤ 0,03	≤ 0,03
6	Niken	-	≤ 0,25
7	Crom	0,9 – 1,2	0,85 – 1,25
8	Molipden	0,15 – 0,3	0,15 – 0,35
9	Đồng

With SCM440H on the above chemical composition, we can see the most obvious difference between these two steel lines is the following:
- Carbon content: Carbon is the most important element, deciding mainly on organization, properties (mechanical properties) and use of steel. Carbon has the most influence on HRC hardness. Quantitatively, it is assumed that carbon increase by 0.01%, HRC hardness will increase by about 25 units. The carbon content in steel SCM440H is slightly higher than SCM440, so it leads to higher hardness and cutting processing also depends on this factor.
- Manganese content: Manganese is added to steel as Fero Manganese to de-oxidize steel in a liquid state to eliminate harmful FeO. Manganese has a good influence on mechanical properties, when dissolved in ferrite, it increases the strength and hardness thus increasing the mechanical properties of steel. In addition, Manganese also has the effect of mitigating the harmful effects of Sulfur. Manganese content in steel SCM440H is slightly higher than SCM440 so it leads to higher durability.
- Chromium content: Chromium is a common chemical element for alloying, being a medium carbide. Chromium increases synthesis properties, it also has the effect of improving durability at high temperatures because it produces fine carbides when ram is secreted at 2500 ° C. In addition, chromium also increases the anti-oxidant properties due to the formation of very durable Cr2C3. Therefore, the chromium content of SCM440H steel is slightly higher than SCM440H, which helps SCM440H's antioxidant ability better.
- Molipden content: The added molybdenum additive will increase the local wear hole resistance and better crack cracking. Molipden helps combat the effects of chloride. Therefore, the content of Molipden in steel SCM440H is better than SCM440 will help SCM440H's corrosion resistance better.
3. Compare SCM440H and SCM440 solid steel in terms of properties
a. Characteristics of steel SCM440
Based on the table of basic chemical components, SCM440 steel has the following typical characteristics:
- High deformation resistance and abrasion resistance;
- Homogeneous hardness on all dimensions;
- Easily machined by wire;
- Tensile strength of about 10.0;
- The load, abrasion and impact resistance of SCM440 steel is greatly improved and superior to carbon steel S45C, S50C, S55C.

SCM440 solid steel
b. Characteristics of solid steel SCM440H
- Good resistance to deformation;
- Resistant to good load, durable, abrasion resistant and withstand working intensity even during use;
- Good cutting processing;
- Hardness before heat treatment of solid steel SCM440H from 10 HRC - 13 HRC.
4. Compare SCM440H and SCM440 solid steel for application
With the above-mentioned mechanical properties, SCM440 and SCM440H steels are often used in mechanical processing.
a. SCM440 steel
- SCM440 steel is suitable for machine parts with high load capacity, high abrasion resistance and impact such as gears, motor shaft, screws, bolts;
- In addition, SCM440 steel is commonly used in the manufacture of automobile engines, motorcycles and industrial machine parts;
- SCM440 steel is also suitable for making mold steel (plastic molds, rice husk molds, ...);
- Anchor bolts for telecommunication broadcasting stations;
- Operation shafts used in sugar cane presses of a sugar factory;
- Rolling shafts and pinions in a system of steel rolling mills;
b. SCM440H solid steel
- SCM440H steel is often used in shipbuilding, factory structures, wharves, mechanics, civil engineering, boats, decks, trains.
- In particular, SCM440H solid steel is often used in the manufacturing industry - in the mold manufacturing industry, precision mechanical processing, load-bearing details such as screws, bolts, shafts, gears, .. .
Hopefully the article "Comparison of solid steel SCM440H and SCM440" will help readers have a closer look at these two steel lines to get a suitable choice. If you want more detailed advice on the type of industrial steel, readers can contact 0332 91 61 61 or chat online with us.
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