I ordered a set of speed bleeders for my car but the ones they sent me are a different thread size for the replacement calipers I purchased, needless to say I ordered them by make and year instead of bleeder size. They offer 3 different thread sizes for the same size bleeder 10mm. I need one with a courser thread than the one they sent but I'm not sure if it's the 1.25 or 1.5, how can I measure it??

 

Go buy two bolts from anywhere in those thread sizes and see which fits.

 

yeah I thought of that just thought maybe there was another way. Do they make some sort of guage to measure thread size?

 

I think they make a flat plastic gauge that'll tell you about the bolt. I'm not 100% sure but I think you can get them at a local hardware store.

Looks like these.

http://www.atlanticfasteners.com/technical/gauges.html

David

 

If you know of a machine shop locally, go there and they could measure it for you. Or go to sears, they have them too.

 

Thread pitch is measure by TPI (threads per inch) for standard hardware, or (on a limb), thread spacing for metric. So a 1.25 pitch metric bolt will have 8 threads in 10mm.
You can use a knife or any thin straight edge to count teeth.