Alloy Steel Shaft

Sin Shun Huat offers and supplies special steels for special requests and demands. One of the significant product is Alloy Steel Shaft. Alloy steel contains small amount of variety alloy elements such as manganese, molybdenum, chromium and etc, where these elements are the key in determining the properties of different grades of Alloy Steel.


We generally offer two different Alloy Steel Shafts: AISI 4140 Round Bar and AISI 4340 Round Bar. AISI 4140 Alloy Steel Shaft is commonly known as 709 Shafts, while 705 Shafts for AISI 4340.Both of these Alloy Steel Shafts are classified as low-alloy steels, showing that two alloys are essentially the same. These alloys have a very high percentage similarity (can be up to 98%) of their average alloy composition in common. However, AISI 4340 is slightly better (tougher) than AISI 4140 in comparing the toughness because AISI 4340 contains Nickel.


Both Alloy Steel Shafts can be used in gears and shafts or other equipment or structural parts. AISI 4140 Alloy Steel Shafts are more typical acquired due to the cost variances. AISI 4340 Alloy Steel Shafts then can be used on heavy duty parts that subject to the toughness demand and/or strictness, such as aircraft landing gears.


4140 EN19 SCM440H 1.7225
4340 EN24 SNCM447H 1.6565
Material C Si Mn Ni Cr Mo S P
AISI 4140 0.40% 0.20% 0.80% 1.00% 0.20% 0.025% 0.025%
AISI 4340 0.40% 0.25% 0.70% 1.80% 0.80% 0.25% 0.025% 0.025%

Average Alloy Composition – Average Values %

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