The image above represents knoop hardness number. To calculate knoop hardness number, two essential parameters are needed and these parameters are Load Applied (P) and Length of Indenter Tip (l).
The formula for calculating knoop hardness number:
HK = 14.2P/l²
Where:
HK = Knoop Hardness Number
P = Load Applied
l = Length of Indenter Tip
Given an example;
Find the knoop hardness number when the load applied is 21 and the length of indenter tip is 3.
This implies that;
P = Load Applied = 21
l = Length of Indenter Tip = 3
HK = 14.2P/l²
That is, HK = 14.2(21)/(3)²
HK =Â (298.2)/(9)
HK = 33.13
Therefore, the knoop hardness number is 33.13.
Read more: How to Calculate and Solve for Vicker’s Hardness Number | Mechanical Properties
Calculating the Load Applied when the Knoop Hardness Number and the Length of Indenter Tip are Given
P = HK(l2) / 14.2
Where:
P = Load Applied
HK = Knoop Hardness Number
l = Length of Indenter Tip
Let’s solve an example;
Given that, the knoop hardness number is 14 and the length of indenter tip is 2. Find the load applied?
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This implies that;
HK = Knoop Hardness Number = 14
l = Length of Indenter Tip = 2
P = HK(l2) / 14.2
P = 14(22) / 14.2
So, P = 14(4) / 14.2
P = 56 / 14.2
P = 3.94
Therefore, the load applied is 3.94.
Calculating the Length of Indenter Tip when the Knoop Hardness Number and the Load Applied are Given
l = √14.2P / HK
Where:
l = Length of Indenter Tip
HK = Knoop Hardness Number
P = Load Applied
Let’s solve an example;
Find the length of indenter tip when the knoop hardness number is 8 and the load applied is 6.
This implies that;
HK = Knoop Hardness Number = 8
P = Load Applied = 6
l = √14.2P / HK
l = √14.2 (6) / 8
So, l = √85.2 / 8
l = √10.65
l = 3.26
Therefore, the length of indenter tip is 3.26.
Read more:Â How to Calculate and Solve for Brinell Hardness Number | Mechanical Properties
How to Calculate Knoop Hardness Number With Nickzom Calculator
Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the knoop hardness number.
To get the answer and workings of the knoop hardness number using the Nickzom Calculator – The Calculator Encyclopedia. First, you need to obtain the app.
You can get this app via any of these means:
Web – https://www.nickzom.org/calculator-plus
To get access to the professional version via web, you need to register and subscribe to have utter access to all functionalities.
You can also try the demo version via https://www.nickzom.org/calculator
Android (Paid) – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator
Android (Free) – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator
Apple (Paid) – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8
Once, you have obtained the calculator encyclopedia app, proceed to the Calculator Map, then click on Materials and Metallurgical under Engineering.
Now, Click on Mechanical Properties under Materials and Metallurgical
Now, Click on Knoop Hardness Number under Mechanical Properties
The screenshot below displays the page or activity to enter your values, to get the answer for the knoop hardness number according to the respective parameter which is the Load Applied (P) and Length of Indenter Tip (l).
Now, enter the values appropriately and accordingly for the parameters as required by the Load Applied (P) is 21 and Length of Indenter Tip (l) is 3.
Finally, Click on Calculate
As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the knoop hardness number and presents the formula, workings and steps too.
