Test: testing the cutting blade’s samples

Objective: The client's company specializes in the manufacturing of cutting tools for logging. A need to measure the hardness of cutting blades of the instruments surged.

Testing target: cutting blades of the logging tools with the thickness equal to 1,5-2 mm. 

Hypothesis and the preparation for the experiment: to inform the customer about the hardness tester's performance, we asked them to provide us with two samples for testing. On delivery, we commenced the experiment.

The samples have a small thickness (1,5 – 2 mm), which's why our laboratory team's professionals opted for a UCI TKM-459CE hardness tester. They used two models - "A" and "H" with test loads equal to 50H and 10H, respectively.

Peculiarities: Ultrasonic Contact Impedance Method (or method of UCI), which is the base of the TKM-459CE operation, requires the thickness of the tested object to be equal to at least 5 mm – according to the DIN 50159 standard. Otherwise, the measurement results may become distorted.

There are many ways to obtain the necessary thickness rate. Our experts had chosen to rub the blades to the base using the "Tsiatim" lubricant. You can see the result in the photos below.

Detailed requirements to tested objects, the thickness of which is not satisfactory, are listed in the Manual that comes together with hardness testers manufactured by the research and production company "Mashproject."

The measurements provided the following data:

	Model "A"	Model "H"
Sample 1
Readings, HRC	62,7; 63,8; 62,6; 62,7; 62,7	64,5; 63,5; 63,1; 63,7; 64,1
Average, HRC	62,9	63,8
Sample 2
Readings, HRC	62,1; 64,8; 65,1; 64,8; 63,7	64,0; 64,6; 65,5; 64,6; 65,7
Average, HRC	64,1	64,9

Our customer found the tests' results satisfying and decided that the best choice for him would be the model "A" of our UCI hardness tester.

Our recommendations: despite the small difference in results obtained with two probes, we would advise using model "H" to satisfy the costomer's needs because its test load is lighter, and the imprint left by the indenter is much slighter.

Below you can see the main features of the "A" and "H" models:

Properties		Model «А»	Model «H»
Test load		50H (5 kg/11,02 lb)	10H (1 kg/2,2 lb)
Lengh/indenter diameter		148 / 26 mm	148 / 26 mm
Weight/roughness rate of the tested object		1 kg / Ra 1,6	1 kg / Ra 0,8
Min diameter of the testing spot		1 mm	1 mm
Average possible diameters of imprints (mm) left on the product surface
Examples of hardness rate readings	42,5 HRC	0,13	0,07
	63,0 HRC	0,09	0,05
Conventional average values of the imprints' depth (mm), that were left on the tested object's surface
Examples of hardness values	42,5 HRC	0,037	0,020
	63,0 HRC	0,025	0,014

Address professionals from research and production company "Mashproject" to choose the best instruments for your technical needs.