SAE 8620 Alloy Steel – Equivalent, Chemical Composition, Properties and Uses

by AMC

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Posted on December 12, 2023 at 12:57 PM

SAE 8620 Alloy Steel (UNS G86200) – Equivalent, Chemical Composition, Properties and Uses

SAE 8620 is a highly sought-after steel alloy, recognized for its impressive combination of strength, hardness, and resistance to wear. This alloy, known as SAE 8620 Alloy Steel, is widely utilized in manufacturing components for automobiles, machinery, and defense equipment. In this blog post, we will explore the various applications of UNS G86200 steel and highlight its remarkable properties. Additionally, we'll discuss how it can undergo heat treatment and machining for diverse applications.

SAE 8620 Alloy Steel Chemical Composition

Element	Content (%)
Iron, Fe	96.895-98.02
Manganese, Mn	0.700-0.900
Nickel, Ni	0.400-0.700
Chromium, Cr	0.400-0.600
Carbon, C	0.180-0.230
Silicon, Si	0.150-0.350
Molybdenum, Mo	0.150-0.250
Sulfur, S	≤ 0.0400
Phosphorous, P	≤ 0.0350

SAE 8620 Alloy Steel Physical Properties

Properties	Metric	Imperial
Density	7.85 g/cm3	0.284 lb/in³

AISI 8620 Mechanical Properties

Properties	Metric	Imperial
Tensile strength	530 MPa	76900 psi
Yield strength	385 MPa	55800 psi
Elastic modulus	190-210 GPa	27557-30458 ksi
Bulk modulus (typical for steel)	140 GPa	20300 ksi
Shear modulus (typical for steel)	80 GPa	11600 ksi
Poisson’s ratio	0.27-0.30	0.27-0.30
Izod Impact	115 J	84.8 ft.lb
Hardness, Brinell	149	149
Hardness, Knoop (converted from Brinell hardness)	169	169
Hardness, Rockwell B (converted from Brinell hardness)	80	80
Hardness, Vickers (converted from Brinell hardness)	155	155
Machinability (hot rolled and cold drawn, based on 100 machinability for AISI 1212 steel)	65	65

SAE 8620 Thermal Properties

Properties	Metric	Imperial
Thermal conductivity	46.6 W/mK	323 BTU in/hr.ft².°F

SAE 8620 Steel Equivalent

AISI 8620	AMS 6274	AMS 6276	AMS 6277	AMS 6375	ASTM A29
ASTM A322	ASTM A331	ASTM A506	ASTM A507	ASTM A513	ASTM A519
ASTM A646	ASTM A752	ASTM A829	MIL S-8690	SAE J1397	SAE J404
AFNOR 20 NCD 2	AFNOR 22 NCD 2	DIN 1.6523	UNI 20 NiCrMo 2	JIS SNCM 21	JIS SNCM 21 H
B.S. 805 H 20	B.S. 805 M 20	AMS 6274G	AMS 6276C	AMS 6277A	ASTM A505
MIL SPEC MIL-S-16974	SAE J404	SAE J770

AISI 8620 Steel Uses

The versatility of AISI 8620 steel renders it a top choice for various applications. Predominantly, it is employed in the manufacturing of automotive components, specifically gears and shafts. Beyond the automotive sector, AISI 8620 is frequently utilized in crafting components for agricultural machinery and in general engineering applications. The exceptional wear resistance of this steel makes it particularly well-suited for a diverse array of automotive parts. These include camshafts, drive shafts, transmission cases, differential housing assemblies, axle housings, flywheels, connecting rods, crankshafts, and steering knuckles.

SAE 8620 Corrosion Resistance

Corrosion resistance is a standout feature of AISI 8620 alloy, primarily attributable to its elevated chromium content. This steel exhibits remarkable resistance to corrosion, enduring exposure to harsh environments like seawater or acid rain. This quality extends its applicability to marine contexts and other settings prone to corrosive elements. Moreover, the heightened chromium content contributes to effective oxidation resistance, enabling the steel to perform well at elevated temperatures, reaching up to 650°F (343°C).

AISI 8620 Heat Treatment

AISI 8620 lends itself well to heat treatment, with options for quenching or normalizing depending on the specific mechanical properties desired for the intended application. In the quenching process, the steel is heated beyond its critical temperature and then rapidly cooled in oil or water. Conversely, normalizing involves heating the steel above its critical temperature and allowing it to cool slowly in still air. The chosen method, coupled with subsequent tempering, can yield varying tensile strengths for SAE 8620, spanning from 545 MPa (79 ksi) to 795 MPa (115 ksi).

SAE 8620 Steel Machining

AISI 8620 stands out for its ease of machining, a quality attributed to its low carbon content and the presence of additional alloys like molybdenum. These characteristics contribute to reduced cutting forces during machining operations. This makes AISI 8620 particularly well-suited for precision components that demand tight tolerances or intricate profiles, such as those found in firearms applications or aircraft components where precision is paramount. Additionally, its relatively low sulfur content enhances machinability by minimizing tool wear during cutting operations, resulting in heightened production efficiency and lower costs per part produced.

Conclusion:

AISI 8620 emerges as a preeminent steel in today's market, distinguished by its impressive amalgamation of strength, hardness, and wear resistance. This versatile alloy finds application across diverse sectors, including automotive components, agricultural machinery, defense equipment, firearms components, aircraft parts, and marine applications. Its high chromium content ensures excellent corrosion resistance, while its machinability sets it apart—allowing for efficient production with minimal tool wear. With proper heat treatment, AISI 8620 can attain tensile strengths ranging from 545 MPa (79 ksi) to 795 MPa (115 ksi), making it an optimal choice for precision components demanding exacting tolerances. In sum, AISI 8620 stands as an exceptional steel alloy, delivering outstanding performance across a spectrum of applications.

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