Is this an OK buy, or hold out for something better?

[wquiles]

These would be my first thread micrometers:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=120327777767

So what do you guys think? Good enough or not worth buying?

Will

 

[gadget_lover]

Doing a quick search, I found what looks to be the same micrometer for 1/2 that, though it does only 0 - 1 inch. 5 anvils instead of 10, but since the anvil centers on the sides of the thread, it's quite reasonable to see 5 covering the range from 5 to 64 TPI.

http://www.shars.com/products/view/1824/01quot_Screw_Thread_Micrometer

I've read that for production use carbide anvils are much better, but since we work with parts that have such a wide tolerance, the minor wear on a tool steel tip should be of little conesequence.

Daniel

 

[Rothrandir]

I personally would never advise buying a chinese measuring tool, but there are plenty of people who do it and they work fine for them.

SPI (another cheap company I don't particularly care for) sells tips that go on standard micrometers, the benefit is being able to put them onto any size mic and getting a measurement. I wouldn't feel comfortable trying to hold tenths with them, but they're much more versatile than a thread mic. If I recall correctly, they are somewhere between $50, and $100.
The only problem might be if you only have a 0-1 mic, but need to measure threads close to or over an inch. The tips take out .450" of travel, so if you want to measure a 7/8 thread for example, you need to put them onto a 1-2" mic.

 

[wquiles]

Doing a quick search, I found what looks to be the same micrometer for 1/2 that, though it does only 0 - 1 inch. 5 anvils instead of 10, but since the anvil centers on the sides of the thread, it's quite reasonable to see 5 covering the range from 5 to 64 TPI.

http://www.shars.com/products/view/1824/01quot_Screw_Thread_Micrometer

I've read that for production use carbide anvils are much better, but since we work with parts that have such a wide tolerance, the minor wear on a tool steel tip should be of little conesequence.

Daniel

The one I posted is the price for "both" the 0-1" and the 1-2", so the price seens to be similar then, right?

Will

 

[wquiles]

I personally would never advise buying a chinese measuring tool, but there are plenty of people who do it and they work fine for them.

SPI (another cheap company I don't particularly care for) sells tips that go on standard micrometers, the benefit is being able to put them onto any size mic and getting a measurement. I wouldn't feel comfortable trying to hold tenths with them, but they're much more versatile than a thread mic. If I recall correctly, they are somewhere between $50, and $100.
The only problem might be if you only have a 0-1 mic, but need to measure threads close to or over an inch. The tips take out .450" of travel, so if you want to measure a 7/8 thread for example, you need to put them onto a 1-2" mic.

Point taken. The dial calipers that I use every single time is a much-nicer-than average MITUTOYO with carbide tips on both the inside and outside jaws - simply outstanding

For these thread mic's, I would use them only every now and then, and right now I don't have any, and I don't know if it is worth buying a nice set that would simply get little use

Will

 

[LukeA]

Point taken. The dial calipers that I use every single time is a much-nicer-than average MITUTOYO with carbide tips on both the inside and outside jaws - simply outstanding

For these thread mic's, I would use them only every now and then, and right now I don't have any, and I don't know if it is worth buying a nice set that would simply get little use

Will

Are you afraid of them losing value? You can always sell them later.

I believe I have the same calipers as you and I'm fairly certain that they'll outlast me.

 

[modamag]

Will, I got my Tesa 0-1 (B&S) for $70 of eBay. IMHO it's better than Mitutoyo for the $$$.

Regardless of which one you want, try to get one that's loaded with anvils. These are really expensive if you have to buy them individually.

The low budget route for this is 3-wires measurement :nana:

 

[precisionworks]

For these thread mic's, I would use them only every now and then,

I've never owned thread mics, as each anvil is limited to a small tpi range - the reason that two mics come with 22 anvils. It's almost as fast, and always more accurate, to use wires. Thread wires take a little getting used to, but once you use them a few times, it becomes second nature.

http://littlemachineshop.com/products/product_view.php?ProductID=1962

Less than $22 for the set

 

[gadget_lover]

I read a post recently where a guy put the ends of the wires through a glob of modelling clay to keep them orderly while he aranged his mic over them.

I have the wires but have not needed them, since I either have the mating part to test fit or I am cutting them to my own specs, which don't need a lot of precision.

Daniel

 

[Rothrandir]

I read a post recently where a guy put the ends of the wires through a glob of modelling clay to keep them orderly while he aranged his mic over them.

I have the wires but have not needed them, since I either have the mating part to test fit or I am cutting them to my own specs, which don't need a lot of precision.

Daniel

Another trick is to add a dab of some kind of grease onto the pins where they go into the thread. Does it change the measurement? Maybe, but no more than you'd be able to reliably measure anyway

 

[Torque1st]

Another trick is to add a dab of some kind of grease onto the pins where they go into the thread. Does it change the measurement? Maybe, but no more than you'd be able to reliably measure anyway

I use the grease method also.

 

[wquiles]

Thanks to your feedback, I got a set of wires instead. Now to learn how to use them - any tips?

Will

 

[precisionworks]

Will,

Take a look at:

http://www.vankeuren.com/tmo.aspx

http://www.practicalmachinist.com/vb/showthread.php?p=996009

I always mount the micrometer in a mic stand, which makes the process ten times easier.

 

[Torque1st]

Normally your part will be in the lathe when measurements are taken. Using a dab of grease will help hold the wires in place while measuring.

For ID threads make a go no-go gauge with the wires.

 

[KC2IXE]

Normally your part will be in the lathe when measurements are taken. Using a dab of grease will help hold the wires in place while measuring.

For ID threads make a go no-go gauge with the wires.

Another option for "standard" threads is to actually buy a set of thread gages - go/no go plug gages for ID, and ring gages for OD

 

[johnnymceldoo]

I chase threads alot at work, ID and OD and have never used thread mics. I use wire gages for OD or go/no go gages.