Cutting Alumina

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Andrew Robinson
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Re: Cutting Alumina

Post by Andrew Robinson »

Richard Hull wrote:Harbor freight is a great place to buy tooling. It is 100% chi-com and you will not pass the tools down to your children, but for the price and particular service the average home owner might expect from them, they are great!
Except when it comes to multimeters Richard haha ;)
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Richard Hull
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Re: Cutting Alumina

Post by Richard Hull »

The Harbor Freight multimeters are highly accurate at the list price of $5.99 each. (or free)

Andrew refers to a weekend test at a friends home. He noted that the meter on the AC range read voltage from a battery. There is no problem here of course. The solution is simple...Never read a DC battery voltage on the AC range. Try using the DC range were the battery's voltage will be accurate to about +/- .004 volts. This is the average of 5 of the harbor freight meter's error against a Weston standard cell that I ran. My $250.00 fluke was no more or less accurate when run against the cell. I suggest reserving the use of the AC range on the meters to measuring AC voltages where they perform just great.

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Andrew Robinson
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Re: Cutting Alumina

Post by Andrew Robinson »

Haha yeah. Why was he measuring with the AC setting to begin with? I'm guessing he just wasn't paying attention to the meter setting?
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Re: Cutting Alumina

Post by AFW »

Do you have a campus glassblower? If so, he will probably have a diamond saw suitable for the diameter of your tubing.
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Re: Cutting Alumina

Post by ian_krase »

You might be able to just burn through it at the cost of inexpensive normal cutoff wheels. Or score and snap it, potentially.

Also, concentrated NaOH (drano?) will dissolve alumina though I suspect this would be very slow even if heated.
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Dennis P Brown
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Re: Cutting Alumina

Post by Dennis P Brown »

For small diameter Alumina (3/8 inch and under) I have never bothered to use my diamond band saw - rather, I scored it with a triangular file, and broke it by a forceful pull and bend. I then obtained a nice break that just needed some clean up using sand paper on a solid surface. So, methods do depend on size.
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Rich Feldman
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Re: Cutting Alumina

Post by Rich Feldman »

Welcome to the forums, Ian.

Ian and Dennis, thanks for hint about familiar score-and-break method on narrow alumina tubes. I've seen video of an expert snapping a large (maybe 2" diameter) glass tube that way.

Here's a older forum thread about ceramic and handyman tools. I bet the McMaster alumina tubing cuts about the same as old porcelain sinks. In my limited experience, it never hurts to use plenty of water with abrasive wheels on ceramic. viewtopic.php?f=18&t=9988&p=67082
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Re: Cutting Alumina

Post by ian_krase »

Isn't alumina-silica or other type of ceramic usually significantly softer than straight alumina?
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Re: Cutting Alumina

Post by John Futter »

Ian
I think you should be posting in the new user area
you are not adding very much to this old thread
Alumina alumina silica are just about as hard as each other, alumina silica has better resistance to thermal shock
Both need diamond tools to do a GOOD JOB and as has been mentioned a good supply of water to keep the tools from burning up
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