The bar is clamped in a metal vise, so the vise is very slightly heated and that side of the bar is much cooler.
Taken using the Topdon Android attachment.
Metal is pretty reflective in IR range, so you’re mostly measuring the room temp. You could fiddle with the emissivity settings, but the best way I’ve learned to measure reflective objects is small pieces of kapton tape. Highly emissive and doesn’t greatly change the thermals, so you can trust the measurement much more. That 100F temp might be closer to 300F for all we know.
The fact that this comment exists, and that it’s the top votes, is why I’m on Lemmy.
Nice tip! When I buy a thermal cam, I’ll put in an order kapton tape too.
hm, having hacksawed lots of round stock over the years, that’s a lot less heat than we expected! then again the hacksaw blades we use are frequently thrashed hehe :)
I find this, mildly interesting…but really, is that why the hacksaws have the arched support instead of a single blade like other saws?
theres a few reasons!
first, it makes it nice n easy to replace the quite thin and bendy hacksaw blade. you got more room around it to do so!
another cool thing is it also allows you to remove the blade, insert the blade through a hole or something, then reattach the saw.
for example, take a bit of box steel, maybe like this:
(photo from here)
lets say you are in a pinch and need some angle iron, but don’t want to just take an angle grinder to it because maybe you need it to still be precise (enough). this is our end goal:
(photo from here)
first, you’d take out the hacksaw blade, which is just a thin little metal thing. after that you’d put it through the tube, and then reattach it to the saw. if the saw is now stuck inside the tube, you’re on the right track. now you may saw away!
here’s another good albeit nondescript example:
(photo from here)
above all though, we’d say the best thing about the design is that there isn’t usually even an entire inch of blade height inside whatever you’re cutting. this means there is a lot less friction and that you don’t need to keep the blade perfectly straight for every stroke beyond the first few.
plus, when the blade is well in there, you can twist the rest of the saw a little bit, and the blade will simply act as a spring and continue to cut straight! it’s pretty neat.
I agree with the other commenter about why the saw has an arched back. It’s not thermals. That blade is thin steel which is a poor path for heat. The temperature profile is mostly due to radiation and convection to the environment (semi-infinite) and has little to do with the bounds.
I assumed it was because the blades wear quickly, but I wonder if it affects great dissipation too.
Does this also affect bandsaws, with a single, thin blade that moves rapidly? Your assumption was always mine until I saw this photo, and thought about it. Chances are the replaceable blade was the motivator, and heat dissipation was a happy side-effect.
Hot take: 107° is pretty warm
So…warm take?
Luke warm.
Nah as far as I’ve heard,the proverbial Luke is not quite that warm. Neither is any literal Luke who isn’t EXTREMELY sick!
This image
I just finished cutting some 1/8" aluminum panels with an angle grinder and can attest to how hot metal gets when cutting. I kept forgetting where would be hot and got a nice burn across my arm to show for it.
Ouch, hope it mends fast.
Once I used an oscillating multi-tool to saw a 1x2 wall stud that had water damage. It hit a nail and sparked a bit, then started to smoke, and then ignited the sawdust with a little flame shooting out from the cut.
Be careful not to let the fire out of the board
If the magic smoke escapes it won’t be able to power your lights anymore
Wish I thought of thermal imagery when I used a cobalt drill to make a hole in my steel sink for a filter water tap. That shit was dangerous.
Got a dremel recently. Once I get some cutting carving bits and stuff to carve I expect to generate a lot of heat.
