Rockwell hardness delay for reading

[LCoop]

I have bought new Grizzly RH tester years ago. It reads spot on with test blocks. It sits in my clean room that's not the same temp of my knife shop. So basically it or the oil is not as warm as it should be. I have put it in a plastic bag with a heat lamp to warm it up. Bottom line it reads the same whether it's warm or cold. I've tested it multiple times with cold or warm with test blocks. It reads quicker if warm but the same if cold. Bottom line it reads the exact same but the ONLY difference is time it takes for the reading. So I'm saying the ONLY reason to have a not too quick reading is it may damage the pointer. Other wise the reading is the same it just may take longer. Thoughts?
I've done this test for years so you will be hard pressed to convince me otherwise.

 

[J. Hoffman]

Do you have a question or are you just stating your experiences?

 

[Stacy E. Apelt - Bladesmith]

If the delay is too long, you can change ta thinner oil in the dashpot.
If it doesn't bother you, you are correct ... it does not matter as long as it is slow enough to avoid the indenter slamming down into the test piece.

 

[LCoop]

Just stating experience I suppose. But I see often on here when talk of hardness testers are brought up it's usually stressed that the time span of applying weighs is critical for fine tuning of the tester. In fact in my experience just as long as it's not TOO fast as it will damage the indenter.

 

[kc custom]

Mine is a Grizzly. Works the same.

Ken

 

[Thescrawnylumberjack]

The only issue I have with mine not being in a temperature regulated space is that in the winter when it’s 20 degrees outside the needle doesn’t want to move at all. Besides that it’s usually spot on.

 

[ScarFoot]

For those of us that have original Wilson Rockwell machines, the instructions are very clear (and very thorough) about the length of time a test should take. It’s not so much about fine tuning as ensuring you’re operating it the way it was intended. Longer tests theoretically shouldn’t change the reading but it allows more time for something to affect the test.

 

[FullyTangy]

For those of us that have original Wilson Rockwell machines, the instructions are very clear (and very thorough) about the length of time a test should take. It’s not so much about fine tuning as ensuring you’re operating it the way it was intended. Longer tests theoretically shouldn’t change the reading but it allows more time for something to affect the test.

And it would indicate that something in the chain of force is out of spec / alignment.

 

[LCoop]

If I know I'm going to do a lot of testing the next day I'll cover it with a tent blanket and put a heat lamp near it for the night. My worry is IF I change the oil viscosity it would drop too fast in the heat of the summer.

y For those of us that have original Wilson Rockwell machines, the instructions are very clear (and very thorough) about the length of time a test should take. It’s not so much about fine tuning as ensuring you’re operating it the way it was intended. Longer tests theoretically shouldn’t change the reading but it allows more time for something to affect the test.

Understood. But test results through multiple years prove different for me. it may take longer but the results are the same.

 

[bladegrinder]

I would never change the viscosity of the oil to try and change the dwell time. there's a knob, on mine anyhow, that can be turned to adjust time dwell time. it's located on the oil reservoir.

 

[ScarFoot]

If I know I'm going to do a lot of testing the next day I'll cover it with a tent blanket and put a heat lamp near it for the night. My worry is IF I change the oil viscosity it would drop too fast in the heat of the summer.

Understood. But test results through multiple years prove different for me. it may take longer but the results are the same.

I’m not doubting your results I’m simply saying that there is an intended way to operate the machine. When people post questions or are having issues with their testers not reading accurately or consistently it’s a valid question to ask how long a test takes and recommend adjusting as needed. If the machine isn’t operating or being operated as intended there is a chance of errant readings. That’s one of the few adjustments recommended for the user to make in the manual.