What is 8620 Steel? Complete Guide 2025

Are you still looking for the right material for your engineering parts project? If so, material 8620 steel is the best choice for machined parts in automotive, machinery and aerospace applications.

AISI 8620 alloy is known for its high corrosion and wear resistance and strength, which makes it the ideal option for transmission components and load-bearing parts. It is mostly employed in oils rigs for drilling. There is a lot more about SAE 8620 steel if you are working with this material. This article will help you understand its core strength and all the possible applications for nay project.

What is 8620 Steel?

AISI 8620 is kwon as low carbon alloy. It has chromium, nickel and molybdenum as alloying elements in its chemical composition which is the reason for its high core strength. It is normally employed in anneal condition with high hardness up to 255HB. When this alloy in its case hardening conditions it has high wear resistance. Compared to other grades of 8000 series, SAE 8620 steel shows better core strength, toughness, and corrosion resistance.

Is 8620 Carbon Steel?

Yes, SAE 8620 steel is a low carbon steel. it also has Ni, Cr and Mo in its chemical composition. It has better properties in carburized form.

Is 8620 Steel Magnetic?

Yes, material 8620 steel is magnetic and can be magnetized. What’s more, it is even the great electromagnetic material It is famous for its high hardness due to case hardening and high core strength.

What Are the Common Forms of 8620 Stainless Steel Material?

The common form and size of AISI 8620 alloy is as:

Material 8620 alloy steel round bar is the best original materials for CNC turning into sleeves and drive shaft.

8620 steel flat bars or blocks are suitable for CNC milling to manufacture bearing blocks, precision housing, etc.

8620 steel square bars is usually machined into transmission shaft with keyway by milling and broaching.

Material Standards and Equivalent Material

Material standards and Equivalent grades for SAE 8620 steel are as:

Advantages and Disadvantages of 8620 Alloy Steel

Advantages of AISI 8620 alloy

• High durability and core strength: 8620 is famous for its high strength. this is due to presence of nickel and chromium which makes it suitable for many applications which require strength and durability.
• In annealed state, 8620 steel has good machinability because the hardness is about 180-230. When machining 8620 material, the cutting force is lower and the tool life can be extended.
• Material 8620 alloy steel has excellent case-hardening capability, which can improve the wear resistance of parts, making it best for components such as gears. Also, the fatigue resistance can be enhanced and the service life of parts can be extended.
• High mechanical properties: SAE 8620 steel offers robust mechanical features like wear resistance, corrosion resistance, core strength, hardness due to its unique chemical composition.

Disadvantages of AISI 8620 alloy

• Low weldability: after post-carburizing and quenching, the welding of AISI 8620 alloy can be challenging and requires special equipment and skilled labor. Also, welding can decrease the mechanical features of SAE 8620 steel.
• High temperature oxidation: oxidation can occur at elevated temperatures which can reduce the service life of alloy. heat treatments are necessary to overcome this issue.
• Low Hardness: If 8620 alloy steel is not subjected to heat treatment, its hardness is relatively low.

What is 8620 Stainless Steel Used for: Applications and Parts

There are many applications of ASIS 8620 alloy.

Gear Manufacturing

8620 steel’s high toughness, wear resistance and core strength due to case hardening make it ideal for gears manufacturing. It can withstand heavy loads and friction. It is a common to use in automotive transmission and industrial machineries.

Automotive parts

Automobile parts like crankshafts, camshafts or connecting tods are mostly made of SAE 8620 steel. It can withstand high loads and strain which is ideal for critical engine components.

Structural components

8620 is employed in construction where a combination of strength and ductility are required. In mechanical systems, it is employed in shafts, pins and axle and other important parts.

Heavy Machineries

Machinery like mining equipment, agricultural, construction and transportation are mostly made of AISI 8620 alloy due to high wear resistance and toughness.

Composition and Microstructure

Chemical composition has a great impact on microstructure. 8620 chemical composition and microstructure details are as:

Chemical Composition

Presence of Cr, Ni and Mo are reasons for high corrosion resistance, toughness and wear resistance, respectively. Low carbon can increase ductility, but carburizing increases its hardness.

Microstructure

SAE 8620 steel is a low carbon alloy to mainly contains pearlite and ferrite in its microstructure. It is normally in the form of a hot bar rolled and cold processed to contain proeutectoid and Widmanstätten ferrite.

Corrosion Resistance

The outstanding feature of SAE 8620 steel is its corrosion resistance. presence of chromium increases its endurance to many environments. It is a common material to use in oils rigs for better corrosion properties.

Atmospheric corrosion

It has better resistance to environmental corrosion. It can survive outdoor environments without losing its mechanical properties and other reliable features.

Aqueous corrosion

This alloy has outstanding resistance to harsh environments like salty water and seawater. It is used in pumping and drilling of oil.

High-temperature corrosion

Heat treatment is required before exposing this alloy to high temperatures to avoid oxidation. Otherwise, elevated temperature can be damaging to the properties of this alloy.

Specific chemical environments

It has high resistance to acid rain. AISI 8620 alloy can be exposed to harsh environments.

Physical Properties

The physical properties of SAE 8620 steel are as:

Mechanical Properties

The mechanical properties of AIS 8620 alloy are as:

Manufacturing and Process

The manufacturing processes for 8620 are as:

Forming

Forming of SAE 8620 steel can be done by conventional method before and after the heat treatment.

Welding

Gas or arc welding can be done on alloy 8620 in as rolled condition. Preheating is required at 400F

Machining 8620 Steel

Machining before heat treatment can be done on 8620. After heat treatment or case hardening, it must be minimum to retain the results of heat treatment.

Grinding

Grinding after heat treatment for 8620 can be challenging. It is recommended not to perform grinding after case hardening of AISI 8620.

How to heat treat 8620 steels

The heat treatment of AIS 8620 alloy are as:

Quenching and tempering

Summarize Differences Between of 8620 Stainless Steel Properties

The properties of AIS 8620 alloy are as:

Design Considerations for 8620 Stainless Steel CNC Parts

8620 stainless steel rust

AISI 8620 steel has quite low rust resistance because it lacks of Cr element, therefore, it is easy to rust in damp or outdoor environments.

Mechanical requirements

Heat treatment increases the mechanical properties of 8620. Case hardening adds the hardness in SAE 8620 steel.

Corrosion resistance requirements

Corrosion resistance of 8620 is very high and it can survive harsh conditions.

processing considerations

AISI 8620 alloy can be processed with any conventional methods. However, after heat treatment, different factors must be considered and usually it is not recommended to undergo processing after heat treatment.

Cost-effectiveness

AISI 8620 is a cost-effective material. This is due to chemical composition which does not contain expensive elements in heavy amounts.

AISI 8620 VS Other Material

4140 vs 8620 steel

The core difference between 4140 and 8620 steel is their hardness. 4140 steel is hardened and tempered steel, while 8620 steel is carburizing steel. AISI 8620 has a harder surface, but 4140 is stronger throughout its entire body. Therefore,4140 has higher hardness than 8620.

4320 steel vs 8620

Both of them are carburizing steel, but 4320 steel is usually considered the stronger verision of 8620 steel. Compared with 8620, 4320 alloy steel has higher Nickel content, which can make it much stronger. So, 4320 has higher wear resistance and abrasion resistance than 8620.

8620 vs 8630 steel

8620 and 8630 have almost the same properties. The key difference between them is the carbon content. 8620 alloy steel contains about 0.18-0.23% content, while 8630 contains higher carbon element up to 0.28-0.33%.

8620 vs 9310 steel

They are different because of the alloy composition and performance. 9310 steel has abouth 0.08-0.13% carbon content, which is lower than that of 8620 steel. However, 9310 contain significantly higher Ni, Cr and Mo content. Therefore, after carburizing, 9301 has high shock resistance and can endure more stress than 8620.

Conclusion

Material 8620 is a low-alloy carburizing steel, widely used in automotive, aerospace,industrial and heavy-duty components due to its excellent surface hardness and toughness after carburizing. It is ideal for gears, shafts, bushings, and other parts because it can achieve a hard, wear-resistance surface. 8620 steel is also called SAE 8620, AISI 8620, or UNS G8620. If you are looking for material for manufacturing parts subjected to load, friction or impact, 8620 steel is your best option. Tuofa CNC steel machining service can ensure the precision and quality of your parts, what’s more, complex design can be accepted