Steel Grades

Question 1

10xx

Answer 1

Plain Carbon

Basic steel known for its versatility. Carbon content usually ranges from 0.08-0.95%
Min 1.00% max

Question 2

10Bxx

Answer 2

Plain Carbon, Boron treated for N2 control

Boron improves strength and helps form martensitic structures and prevents the formation of softer phases like ferrite during heat treatment

Question 3

11xx

Answer 3

Plain Carbon, resulfurized

Sulfur added for ease of machining

Question 4

12xx

Answer 4

Plain Carbon, resulferized and rephosphorized
Good for machining

Question 5

15xx

Answer 5

Plain Carbon/high Manganese- “Microalloy”
Mn 1.00-1.65%

Question 6

40xx

Answer 6

Molybdenum
Mo 0.2-0.25%
Structural alloy (axles, gearshafts, spindles). Has high strength, corrosion resistance, and can withstand extreme temps

Question 7

51xx

Answer 7

Cr 0.8-1.05%
High hardenability

Question 8

86xx

Answer 8

Ni 0.55%
Cr 0.50%
Mo 0.20%

Question 9

87xx

Answer 9

Ni 0.55%
Cr 0.50%
Mo 0.25%
Armor plating, comps for industrial machines, and lightweight but durable structures

Question 10

92xx

Answer 10

Si 1.40-2.00%
Mn 0.65-0.85%
Cr 0-0.65%

Question 11

13xx

Answer 11

Mn 1.75%
Higher levels of Mn allow for more flexibility in the heat treating process

Question 12

23xx

Answer 12

Ni 3.5%
Improves low temp toughness and harden ability deep with parts, corrosion and abrasion resistance, reduces distortion and cracking when quenched

Question 13

25xx

Answer 13

Ni 5.00%

Question 14

31xx

Answer 14

Ni 1.25%
Cr 0.65-0.8%
Used for food and surgical applications

Question 15

32xx

Answer 15

Ni 1.75%
Cr 1.07%

Question 16

33xx

Answer 16

Ni 3.50%
Cr 1.5-1.57%

Question 17

34xx

Answer 17

Ni 3%
Cr 0.77%

Question 19

44xx

Answer 19

Mn 0.4-0.52%

Question 20

41xx

Answer 20

Cr 0.5-0.95%
Mo 0.12-0.3%
Medium carbon ultra-high strength low alloy steel. Often called chromoly steel

Question 21

43xx

Answer 21

Ni 1.82%
Cr 0.5-0.8%
Mo 0.25%

Question 22

47xx

Answer 22

Ni 1.05%
Cr 0.45%
Mo 0.2-0.35%
Used in tube cutting, bending, forming, and machining

Question 23

46xx

Answer 23

Ni 0.85-1.82%
Mo 0.20-0.25%
Heavy duty machinery, automotive parts, and cutting tools

Question 24

48xx

Answer 24

Ni 3.50%
Mo 0.25%
Industrial thermostats due to its stable thermal expansion characteristics and high-temp operating ability

Question 25

50xx

Answer 25

Cr 0.27-0.65%

Question 26

50xxx

Answer 26

Cr 0.5% C 1.00% min

Question 27

51xxx

Answer 27

Cr 1.02% C 1.00% min

Question 28

52xxx

Answer 28

Cr 1.45% C 1.00% min

Question 29

61xx

Answer 29

Cr 0.60-0.95% V 0.10-0.015% High speed steel

Question 30

72xx

Answer 30

W 1.75% Cr 0.75%

Question 31

81xx

Answer 31

Ni 0.30% Cr 0.40% Mo 0.12%

Question 32

88xx

Answer 32

Ni 0.55% Cr 0.50% Mo 0.35% High strength weldable steel known for its resistance to corrosion

Question 33

93xx

Answer 33

Ni 3.25% Cr 1.20% Mo 0.12% High tensile strength, toughness, and fatigue resistance. Used in aerospace, automotive, and heavy machinery

Question 34

94xx

Answer 34

Ni 0.45% Cr 0.40% Mo 0.12% High strength and good formability

Question 35

97xx

Answer 35

Ni 0.55% Cr 0.20% Mo 0.20%

Question 36

98xx

Answer 36

Ni 1.00% Cr 0.80% Mo 0.25% Used in aerospace, oil and gas, and Motorsport