Materials: Carbon Steel

Features and applications of common carbon steel alloys

Low carbon steels generally contain less than 0.25% carbon and cannot be strengthened by heat-treating (strengthening can only be accomplished through cold working). The low carbon material is relatively soft and weak, but has outstanding ductility and toughness. In addition, it is machineable, weld-able, and is relatively inexpensive to produce.

Medium carbon steels have carbon concentrations between 0.25% and 0.60%. These steels may be heat-treated by austenizing, quenching, and then tempering to improve their mechanical properties. On a strength-to-cost basis, the heat-treated medium carbon steels provide tremendous load carrying ability.

An iron-based mixture is considered to be an alloy steel when manganese is greater than 1.65%, silicon over 0.5%, copper above 0.6%, or other minimum quantities of alloying elements such as chromium, nickel, molybdenum, vanadium, or tungsten are present. An enormous variety of distinct properties can be created for the steel by substituting these elements in the recipe to increase hardness, strength, or chemical resistance.

Alloy	UNS Designation	Principal Design Features	Applications
1010	G10100	1010 is a plain carbon steel with a nominal 0.10% carbon content. It is a relatively low strength steel, but it may be quenched and tempered for increased strength.	Used for applications such as cold headed fasteners and bolts.
1018	G10180	1018 is among the most available grades in the world. Despite its unimpressive mechanical properties, the alloy is easily formed, machined, welded, and fabricated. Due to its higher manganese content, it can, in thin sections, be hardened to RC 42.	Often employed in high volume screw machine parts applications, such as shafts, spindles, pins, rods, sprocket assemblies, and an incredibly wide variety of component parts.
1020	G10200	1020 is a commonly used plain carbon steel. It has a nominal carbon content of 0.20% with approximately 0.50% manganese. It has a good combination of strength and ductility and may be hardened and carburized.	Used for simple structural applications such as cold formed fasteners and bolts. It is often used in the case hardened condition.
1022	G10220	1022 has a slightly higher carbon and manganese content plain carbon steel than 1020. It is used for its somewhat greater strength while still having good ductility.	Used for moderate strength structural applications such as cold formed fasteners and bolts. It is often used in the case hardened condition.

Alloy

UNS Designation

Principal Design Features

Applications

1010

G10100

1010 is a plain carbon steel with a nominal 0.10% carbon content. It is a relatively low strength steel, but it may be quenched and tempered for increased strength.

Used for applications such as cold headed fasteners and bolts.

1018

G10180

1018 is among the most available grades in the world. Despite its unimpressive mechanical properties, the alloy is easily formed, machined, welded, and fabricated. Due to its higher manganese content, it can, in thin sections, be hardened to RC 42.

Often employed in high volume screw machine parts applications, such as shafts, spindles, pins, rods, sprocket assemblies, and an incredibly wide variety of component parts.

1020

G10200

1020 is a commonly used plain carbon steel. It has a nominal carbon content of 0.20% with approximately 0.50% manganese. It has a good combination of strength and ductility and may be hardened and carburized.

Used for simple structural applications such as cold formed fasteners and bolts. It is often used in the case hardened condition.

1022

G10220

1022 has a slightly higher carbon and manganese content plain carbon steel than 1020. It is used for its somewhat greater strength while still having good ductility.

Used for moderate strength structural applications such as cold formed fasteners and bolts. It is often used in the case hardened condition.

Alloy	UNS Designation	Principal Design Features	Applications
1030	G10300	1030 is a higher carbon (0.30%) manganese steel in the plain carbon steel alloy family. It provides greater strength than the lower grades while still retaining reasonable ductility.	Generally used in the quenched and tempered condition for strength. Applications include machinery parts where strength and hardness are requisite.
1040	G10400	1040 has a higher (0.40%) carbon content for greater strength than the lower carbon alloys. It is hardenable by heat treatment, quench and tempering to develop 150 to 250 ksi tensile strength.	Used for crankshafts, couplings, and cold headed parts.
1045	G10450	1045 is a medium carbon steel used when greater strength and hardness is desired than in the rolled condition.	Used in gears, shafts, axles, bolts, studs, and machine parts.
1060	G10600	1060 is one of the higher carbon content (0.60%) steels. It is more difficult to fabricate than the lower carbon grades.	Used for hand tools such as screwdrivers, pliers, and similar items.

Alloy

UNS Designation

Principal Design Features

Applications

1030

G10300

1030 is a higher carbon (0.30%) manganese steel in the plain carbon steel alloy family. It provides greater strength than the lower grades while still retaining reasonable ductility.

Generally used in the quenched and tempered condition for strength. Applications include machinery parts where strength and hardness are requisite.

1040

G10400

1040 has a higher (0.40%) carbon content for greater strength than the lower carbon alloys. It is hardenable by heat treatment, quench and tempering to develop 150 to 250 ksi tensile strength.

Used for crankshafts, couplings, and cold headed parts.

1045

G10450

1045 is a medium carbon steel used when greater strength and hardness is desired than in the rolled condition.

Used in gears, shafts, axles, bolts, studs, and machine parts.

1060

G10600

1060 is one of the higher carbon content (0.60%) steels. It is more difficult to fabricate than the lower carbon grades.

Used for hand tools such as screwdrivers, pliers, and similar items.

Alloy	UNS Designation	Principal Design Features	Applications
4130	G41300	4130 is a low alloy steel containing molybdenum and chromium as strengthening agents. The carbon content is nominally 0.30%, and with this relatively low carbon content, the alloy is excellent from the fusion weldability standpoint. The alloy can be hardened by heat treatment.	Used in structural applications such as aircraft engine mounts and welded tubing applications.
4140	G41400	4140 is one of the chromium, molybdenum, manganese alloy steels noted for toughness, good torsional strength, and good fatigue strength.	Used in a tremendous variety of applications.
4340	G43400	4340 is a heat treatable, low alloy steel containing nickel, chromium, and molybdenum. It is known for its toughness and capability of developing high strength in the heat treated condition, while retaining good fatigue strength.	Typically used for aircraft landing gear, power transmission gears and shafts, and other structural parts.

Alloy

UNS Designation

Principal Design Features

Applications

4130

G41300

4130 is a low alloy steel containing molybdenum and chromium as strengthening agents. The carbon content is nominally 0.30%, and with this relatively low carbon content, the alloy is excellent from the fusion weldability standpoint. The alloy can be hardened by heat treatment.

Used in structural applications such as aircraft engine mounts and welded tubing applications.

4140

G41400

4140 is one of the chromium, molybdenum, manganese alloy steels noted for toughness, good torsional strength, and good fatigue strength.

Used in a tremendous variety of applications.

4340

G43400

4340 is a heat treatable, low alloy steel containing nickel, chromium, and molybdenum. It is known for its toughness and capability of developing high strength in the heat treated condition, while retaining good fatigue strength.

Typically used for aircraft landing gear, power transmission gears and shafts, and other structural parts.

Alloy	UNS Designation	C (max)	Mn (max)	P (max)	S (max)	Si	Cr	Ni	Mo
1010	G10100	0.08-0.13%	0.30-0.60%	0.04%	0.05%	–	–	–	–
1018	G10180	0.15-0.20%	0.60-0.90%	0.04%	0.05%	–	–	–	–
1020	G10200	0.18-0.23%	0.30-0.60%	0.04%	0.05%	–	–	–	–
1022	G10220	0.18-0.23%	0.70-1.00%	0.04%	0.05%	–	–	–	–

Alloy

UNS Designation

C (max)

Mn (max)

P (max)

S (max)

1010

G10100

0.08-0.13%

0.30-0.60%

0.04%

0.05%

–

1018

G10180

0.15-0.20%

0.60-0.90%

0.04%

0.05%

–

1020

G10200

0.18-0.23%

0.30-0.60%

0.04%

0.05%

–

1022

G10220

0.18-0.23%

0.70-1.00%

0.04%

0.05%

–

Alloy	UNS Designation	C (max)	Mn (max)	P (max)	S (max)	Si	Cr	Ni	Mo
1030	G10300	0.28-0.34%	0.60-0.90%	0.04%	0.05%	–	–	–	–
1040	G10400	0.37-0.44%	0.60-0.90%	0.04%	0.05%	–	–	–	–
1045	G10450	0.43-0.50%	0.60-0.90%	0.04%	0.05%	–	–	–	–
1060	G10600	0.55-0.65%	0.60-0.90%	0.04%	0.05%	–	–	–	–

Alloy

UNS Designation

C (max)

Mn (max)

P (max)

S (max)

1030

G10300

0.28-0.34%

0.60-0.90%

0.04%

0.05%

–

1040

G10400

0.37-0.44%

0.60-0.90%

0.04%

0.05%

–

1045

G10450

0.43-0.50%

0.60-0.90%

0.04%

0.05%

–

1060

G10600

0.55-0.65%

0.60-0.90%

0.04%

0.05%

–

Alloy	UNS Designation	C (max)	Mn (max)	P (max)	S (max)	Si	Cr	Ni	Mo
4130	G41300	0.28-0.33%	0.40-0.60%	0.035%	0.04%	0.15-0.35%	0.80-1.10%	—	0.15-0.25%
4140	G41400	0.38-0.43%	0.75-1.00%	0.035%	0.04%	0.15-0.35%	0.80-1.10%	—	0.15-0.25%
4340	G43400	0.38-0.43%	0.60-0.80%	0.035%	0.04%	0.15-0.35%	0.70-0.90%	1.65-2.00%	0.20-0.30%

Alloy

UNS Designation

C (max)

Mn (max)

P (max)

S (max)

4130

G41300

0.28-0.33%

0.40-0.60%

0.035%

0.04%

0.15-0.35%

0.80-1.10%

—

0.15-0.25%

4140

G41400

0.38-0.43%

0.75-1.00%

0.035%

0.04%

0.15-0.35%

0.80-1.10%

—

0.15-0.25%

4340

G43400

0.38-0.43%

0.60-0.80%

0.035%

0.04%

0.15-0.35%

0.70-0.90%

1.65-2.00%

0.20-0.30%

Alloy	UNS Designation	Typical Mechanical Properties
1010	G10100	53	44	20	40	105
1018	G10180	64	54	15	40	126
1020	G10200	64	54	24	54	126
1022	G10220	69	58	15	40	137

Alloy

UNS Designation

Typical Mechanical Properties

Tensile (ksi)

Yield (ksi)

Elongation (% in 2″)

Reduction of Area (%)

Brinell Hardness

1010

G10100

105

1018

G10180

126

1020

G10200

126

1022

G10220

137

Alloy	UNS Designation	Typical Mechanical Properties
1030	G10300	76	64	12	35	149
1040	G10400	90	80	12	35	170
1045	G10450	91	77	12	35	179
1060	G10600	118	70	17	34	241

Alloy

UNS Designation

Typical Mechanical Properties

Tensile (ksi)

Yield (ksi)

Elongation (% in 2″)

Reduction of Area (%)

Brinell Hardness

1030

G10300

149

1040

G10400

170

1045

G10450

179

1060

G10600

118

241

Alloy	UNS Designation	Typical Mechanical Properties
4130	G41300	80	56	28	57	149
4140	G41400	150	90	20	45	285
4340	G43400	110	66	23	49	197

Alloy

UNS Designation

Typical Mechanical Properties

Tensile (ksi)

Yield (ksi)

Elongation (% in 2″)

Reduction of Area (%)

Brinell Hardness

4130

G41300

149

4140

G41400

150

285

4340

G43400

110

197

Materials: Carbon Steel

Features and applications of common carbon steel alloys

Low Carbon Steels – Principal Design Features & Applications

Medium Carbon Steels – Principal Design Features & Applications

Alloy Steel – Principal Design Features & Applications

Low Carbon Steels – Chemical Properties

Medium Carbon Steel Chemical Properties

Alloy Steel Chemical Properties

Low Carbon Steels – Mechanical Properties

Medium Carbon Steels – Mechanical Properties

Alloy Steels – Mechanical Properties