relation between strength and hardness of material
relation between strength and hardness of material
(OP)
hello
Can anyone please explain me the relation between strentgh and hardness of the material?
Can anyone please explain me the relation between strentgh and hardness of the material?





RE: relation between strength and hardness of material
RE: relation between strength and hardness of material
On the other hand, there are different types of strength (other than tensile strength) and hardness (other than indention hardness). For example, there is impact strength, compressive strength, chemical strength, magnetic strength, and so on. The correlation between these other types of strength to the indention hardness is much less than that for tensile strength (for some, there is no correlation).
As far as hardness goes, many a machinist has told me that 321 stainless is difficult to machine because it is so hard. 321 SS has relatively low indentation hardness (and correspondingly, tensile strength), however. The machinists know what they are talking about, however, they just do not mean indention hardness when they say that 321 is hard, they mean that it dulls their tools more quickly and gives them more pushback than low-allloy steels. The correlation between this type of hardness and those other types of strength is even more nebulous.
RE: relation between strength and hardness of material
RE: relation between strength and hardness of material
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.
RE: relation between strength and hardness of material
'Impact Strength' is also a common expression but can be misleading as most Impact test measure the energy absorbed and the results of these tests is a much better guide to a materials's toughness rather than strength.
In many cases toughness and strength are mutually exclusive properties and this is when more data is needed to make the correct choices.
I don't understand the idea that there are different types of hardness. I have always thought that hardness is just hardness.
Stainless Steels such as 321 can be difficult to machine but this is due the manner in which they work harden and using the correct machining conditions and lubricants is important to ensure good results. When set up correctly 321 machines well.
For the vast majority of families of metallic materials hardness correlates very well to tensile strength.
RE: relation between strength and hardness of material
Yield strength does not follow hardness or tensile strength very closely.
UTS / Yield strength / UTS/YS
1015 HR 61 45.5 1.34
N 61.5 47 1.31
Annealed 56 41.25 1.36
1040 HR 90 60 1.50
N 85.5 54.25 1.58
Annealed 75.25 51.25 1.47
1340 N 121.25 81 1.50
Annealed 102 63.25 1.61
4130 N 97 63.25 1.53
Annealed 81.25 52.5 1.55
4140 N 148 95 1.56
Annealed 95 60.5 1.57
mil spec 23284
class 1 95 75 1.27
class 2 80 55 1.45
class 3 75 45 1.67
class 4 60 35 1.71
class 5 105 75 1.40
class 6 110 90 1.22
RE: relation between strength and hardness of material