Alloy Steel

4140 Annealed Alloy Steel

4140 Annealed steel bar is a medium carbon, chromium-molybdenum alloy steel that has a high hardenability. This grade is also widely used for forging. 4140 steel also has good fatigue and impact resistance after heat treating. The average hardness for 4140 annealed is 185/200 BHN, but it can be hardened to RC 54.

Applications

Typical applications for this grade include drill collars, pins, axles, bolts, and shafts.

Requirements

Common specifications for this grade:

• ASTM A29
• ASTM A322
• ASTM A108
• ASTM A331

Shapes and Sizes

Peterson Steel supplies 4140 steel bar in a wide range of sizes. The shapes available for this grade include:

• Rounds (HR, CF & F&RT)
• Squares
• Hexagons
• Decarb Free Plate (Blanchard ground & stress relieved)

Standard “4140 Grade” Chemical Composition

Carbon	0.38-0.43
Manganese	0.75-1.00
Phosphorus (max)	0.035
Sulfur (max)	0.040
Silicon	0.15-0.35
Chromium	0.80-1.10
Molybdenum	0.15-0.25

4140 Heat Treated Alloy Steel

4140 Heat Treated is a medium carbon, chromium-molybdenum alloy steel. 4140 HT is the most commonly used high tensile steel with endless applications including everything from gears and pumps to various applications in the automotive and construction industry. 4140 HT has a typical hardness of 28/32 HRC. This grade can also be surface hardened to increase wear resistance.

Application

Typical applications for this grade include drill collars, pins, axles, bolts, and shafts.

Requirements

Common specifications for this grade:

• ASTM A29
• ASTM A322
• ASTM A108
• ASTM A193 Gr B7
• ASTM A434

Shapes and Sizes

Peterson Steel supplies 4140 HT steel bar in a wide range of sizes (METRIC INCLUDED).The shapes available for this grade include:

• Rounds (HR,  F&RT and TG&P)
• Decarb Free Plate (Blanchard ground & stress relieved)

Standard “4140 Grade” Chemical Composition

Carbon	0.38-0.43
Manganese	0.75-1.00
Phosphorus (max)	0.035
Sulfur (max)	0.040
Silicon	0.15-0.35
Chromium	0.80-1.10
Molybdenum	0.15-0.25

 

8620 Alloy Steel

8620 is a low nickel – chromium – molybdenum medium hardenability, case hardening (carburizing) steel, generally supplied in the as rolled condition with a maximum Brinell hardness of 280 (RC30). Characterized by good core strength and toughness in small to medium sections with case hardness up to RC62 when carburized, hardened and tempered. 8620 can also be used (un-carburized) as a high tensile steel, which when suitably hardened and tempered can be utilized for various applications requiring good tensile strength and reasonable toughness.

Applications

Arbors, Bearings, Bushings, Cam Shafts, Differential Pinions, Guide Pins, King Pins, Pistons, Pins, Splined Shafts, Ratchets, Sleeves etc…

Requirements

Common specifications for this grade:

• ASTM A29
• ASTM A322

Shapes and Sizes

Peterson Steel supplies 8620 steel bar in a wide range of sizes. The shapes available for this grade include:

• Rounds (HR, CF & F&RT)

Standard “8620 Grade” Chemical Composition

Carbon	0.17-0.23
Manganese	0.60-0.95
Phosphorus (max)	0.040
Sulfur (max)	0.040
Silicon	0.10-0.40
Chromium	0.35-0.75
Nickel	0.35-0.75
Molybdenum	0.15-0.25

4340 Annealed Alloy Steel

4340 is a medium-carbon nickel-chromium-molybdenum steel alloy with excellent tensile strength, toughness, and fatigue resistance. Since the material usually comes in the annealed condition, additional heat treatments (oil quenching and tempering, or normalizing and tempering) can produce parts with even higher strength and fatigue resistance. 4340 is a wear-resistant material with especially good abrasion resistance, shock- and -impact resistance, and excellent atmospheric corrosion resistance. The alloy also possesses very good ductility, especially in the annealed condition, where it can be easily formed and machined. Applications 4340 finds use in heavy machinery, specifically for the manufacturing of transmission parts, such as heavy-duty shafts, gears, and axles. Requirements Common specifications for this grade:

• ASTM A29
• ASTM A304
• ASTM A322
• ASTM A331

Shapes and Sizes Peterson Steel supplies 4340 steel bar in a wide range of sizes. The shapes available for this grade include:

• Rounds (HR & F&RT)

Standard “4340 Grade” Chemical Composition

Carbon	0.37-0.43
Manganese	0.60-.80
Phosphorus (max)	0.035
Sulfur (max)	0.040
Silicon	0.15-0.30
Chromium	0.70-.90
Nickel	1.65-2.00
Molybdenum	0.20-0.30

52100 Alloy Steel

52100 is a high-carbon chromium alloy steel, which, because of its versatility, is used in a variety of mechanical applications. In the annealed condition this steel is comparatively easy to machine, yet very high hardness and abrasion resistance can be developed by heat treatment to make the steel particularly suitable for applications requiring extreme wear resistance. In addition, 52100 alloy steel can be heat treated to high levels of tensile strength and fatigue strength.

Applications

Anti-Friction Bearings & Rollers, Slitting Rolls, Spacers and Knives, Seals, Sleeves & Bushings, Tools, Dies & Molds, Engine & Hydraulic Parts.

Requirements

Common specifications for this grade:

• ASTM A29
• ASTM A108
• ASTM A295
• ASTM A322

Shapes and Sizes

Peterson Steel supplies 52100 steel bar in a wide range of sizes. The shapes available for this grade include:

• Rounds (HR, CF)

Standard “52100 Grade” Chemical Composition

Carbon	0.93-1.05
Manganese	0.25-0.45
Phosphorus (max)	0.025
Sulfur (max)	0.015
Silicon	0.15-0.35
Chromium	1.35-1.60
Nickel	0.25
Copper	0.30
Molybdenum	0.10