Measuring the maximum temperature of an edge during belt sanding: initial results

Once again, thanks for doing this!

I hate to continue with the requests, but I'd like to see the results of the same test with continuous movement across the belt as you go. 20 seconds in one spot is somewhat extreme application here. A five count is a long time to spend in one place, and even with slow steady movement I'd not expect any specific point on the blade to be in continuous contact for more than 3 seconds on a 1" belt.
 
Cyrano said:
In response to suggestions from bluntcut, I repeated my experiment using real blade steel and a fine-grit belt.

This photo shows the effective magnification of my microscope at its highest setting (nominally 230X), using the calibration target provided with the scope:
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Thank you for your work you've put into this. I'm interested as I have a worksharp now.

So what's supposed to be the take away from this?
 
Thanks for taking the time to do this !

I agree with hh... See if you can keep it moving like you would in a normal sharpening session. Also, what speed are we talking about here in sfpm?
 
Has anybody pointed out that temperature and heat aren't the same thing? You can have a very high temperature without much heat.
 
postoak said:
Has anybody pointed out that temperature and heat aren't the same thing? You can have a very high temperature without much heat.
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Why is that important? I thought that the temperature of the metal determined when it changed state significantly, like with tempering or annealing.

Brian.
 
Can you explain what you're seeing and what your conclusions are? Twenty seconds of firm pressure with a fine-grit belt is more than I'd ever do while sharpening, but I tend to be extra careful with fine-grit belts.

Thanks for continuing to do these experiments.
 
bgentry said:
Why is that important? I thought that the temperature of the metal determined when it changed state significantly, like with tempering or annealing.

Brian.
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It may, but you could raise a few molecules to a high temperature and yet not affect the surrounding areas -- high temperature, low heat.
 
We are discussing heat at the apex of the edge-the part with the least heat capacity.
I think as a steam and refrigeration engineer for 45 years I know what heat is.
 
With respect, apparently not. Heat is the transfer of energy without work or transfer of matter. Temperature can be used to calculate heat transfer but they are two very different things.
 
Joe_Lane said:
With respect, apparently not. Heat is the transfer of energy without work or transfer of matter. Temperature can be used to calculate heat transfer but they are two very different things.
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Isn't friction considered work; in this scenario?
 
This is a great thread!

I can say this: I've used paper wheels for about 1-2 years now and I have ruined an edge or two when in my early learning stages.

My wheels spin at 2,000 rpm and I would consider one of the wheels to be a "medium" grit. When sharpening the blade on a Leatherman (420 steel I believe) I noticed some blue color at the edge. This was moving the blade across the wheels in a normal sharpening motion, and the apex had no more than 2 full seconds of contact with the spinning wheels.

I don't know how fast the WSKO spins, but I thought it was worth mentioning for any paper wheel users.
 
Joe_Lane said:
With respect, apparently not. Heat is the transfer of energy without work or transfer of matter. Temperature can be used to calculate heat transfer but they are two very different things.
Click to expand...
:) lookup temperature in any dictionary, definition is measurement of heat/hot or cold
 
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