anyone know the correct answer?

maybe it's time to go back to elementary school but i'm seeing conflicting reports here online. some sources say its 10 and other sources say 24.3.

so how many millimeters are in an inch?

Please reveal these sources!

Not trying to put anybody on blast Gary. Just looking for the correct answer. Thanks again.

25.4

https://www.unitconverters.net/length/mm-to-inches.htm
https://www.metric-conversions.org/l...-to-inches.htm

Ok. Does anyone sell pinch rollers that are 22 mm? The biggest I can find on eBay is 13 mm

I mis-read your intent and earnestness. I actually thought that this was the beginning of a humor thread, in that the answer (25.4mm per inch) is so readily available.

My flabber is ghasted...

What do you need a pinch roller for? 22mm sounds big for a cassette deck but too small for a normal tape machine.

If it's for a cassette deck, consider Russell Industries. They don't have much info online but you can call them with the model number and they can cross it.

If it's for a regular tape machine, try getting the old one recapped with new rubber by Terry's Rubber Rollers. Cheaper than replacement, and you can keep the old bearings rather than risk replacing them with unknown ones.
--scott

It’s for a webcor reel to reel. It’s just smaller than an inch in diameter.

Is it really possible that pinch roller replacements for real to reel units are that rare? I’m flabbergasted.

Hahaha! Seriously would like to know too

22mm is 7/8" exactly by the way, 13mm is 0.3mm over 1/2" which is 12.7mm, cheers.

Actually it's 22.225mm. For those who are very anaahl like myself.

I think consumer gear like that is not apt to get much support, no. Terry's Rubber Rollers will rebuild it for you. It'll likely cost more than a Webcor machine is worth, but that is how these things go.
--scott

I don’t grok how 22.225 or 24-ish is being offered.
There are some numbers we just have to learn after 10 yrs old.
Yards in a mile: 1,760. Feet in a yard:3 Inches in a foot:12. Grams in a pound:454 and feet in a meter: 3.289811. There are others like π (pi) αnd Euler’s constant.

So 3ft x 12 is 36 inches plus 3.477 (0.289811 x 12) makes 39.477 inches in a meter, another useful baseline number.

We want millimetres per inch or thousandths of a meter per inch.
We know 1 meter = 39.477inches. Divide by a thousand to get inches/millimeter
0.039477, whose reciprocal, millimeters/inch, is 25.331206 millimeters.
This is usually accepted as 25.4-ish or 2.54 centimeters.
This is what we do after a hurricane and the net is down.

it is 25.4 per inch, but if you want to use imperial, just use imperial instead, don't mix the two, nobody that I know of who works in any of the trades including architects ever uses yards anymore, it's pretty much obsolete thesedays.

amen.

We learned something else, 1 m = 100 cm = 1000 mm, 1 km = 1000m.
Moreover, 1 g = 1 cubic cm of water, 1 liter = 1000 g water = 10x 10 cm.
1 ton = 1000 kg.
and so on.

When there is a hurrican we send prayers over the Atlantic.

I was going through customs into New York and they asked what I was doing and I said I was an electrical engineer and so they asked me how many watts were in a horsepower and I had to say "Well... it depends what country you're in... It the US it is 746, In Sweden 735, and in Russia 720...." and the man just boggled but he let me through anyway.
--scott

Thanks for the hurricane prayers - Trinidad needs it about now.

On this side of the great pond we have a mix of old metric, SI and avverdewpwa, sometimes in the same vehicle. Ppl think in pounds and feet here but still encounter cubic meters and CCs, so we can't take a puritan approach to not mixing. Half the tellers in any supermarket cannot make change using base 10, so ounces or grams isn't the issue - arithmetic is.

When I think of stress and deflection it's in foot/lbs not newton-meters; same with pressures, psi, kips or MegaPascals, we have to use them all.
With PCs and now smart phones, conversion is trivial, it's staying focused on the final answer, that's the job.

Ah, horse power, an old Dobbin walking round and round at 2 1/2 mph ((5280'/60)2.5=220ft/min) exerting a steady pull of 150lbs for 8 hours a day. That's all I remember now but I know there are conversions defining a Watt as 40-odd lbs/foot in one minute and Volt per Amp per Sec.
I think a man raising a bucket on a pulley was a 10th of the horse's power per 8 hour day.
I agree that once you need to answer abstract questions and get beyond m3 & m4 we need to standardise on SI units, then convert back to ethnic units if wanted later.

Glad not to have to do this on a slide rule anymore but I have a couple tucked away in their pleatherette holsters
WalterT

I used to work in a facility that had psi, psf, torr, inches of mercury, inches of water, millimeters of mercury, bars, and one gauge that was calibrated in my absolute favorite measure: pounds per square centimeter.
--scott