On Sat, 13 Jul 2013 21:51:42 -0500, "Terry Coombs"
wrote:

"Bob La Londe" wrote in message
...
"BQ340" wrote in message
...
On 7/13/2013 9:39 PM, Terry Coombs wrote:
I'm making a brake line tee for a guy , and I'm having trouble getting
an
acceptable fit . The compression nut reads 9.85 mm x 1mm pitch . The tap
I
bought measures 10.10 ... and the nut is way too loose in the threads .
I'm
wondering if this auto parts store tap is oversize ... might be OK for a
bolt thru a bracket or something , but I'm not using it for this job .
Is
there a chart somewhere that has size data for taps by fit class ?


Flare fittings should be used for brakes, not compression.

For a brake line its typically a double flare fitting. Also, amazingly
enough if you "over" tighten them they are more likely to leak then if you
under tighten them.



Yup , double flare . Looks like a little button on the end of the tube .

Nope, that's a compression fitting. http://tinyurl.com/pz9afu5
25 seconds into the video, you'll see the brass sleeve/button.


Bob
, you wouldn't happen to know the included angle of that seat ? Looks like a
135 deg bit would work , 118 is too steep , it only contacts on the outside
edge . I can grind a bit to any angle in between , thanks to my neighbor .
He gave me a DD500X for fixing his older model.

Terry, I'm not sure you have the proper picture on the task.
Here's the picture for a double flared tube. The seat must be a
convex shape, not concave, so the bit will have to have a cone rather
than a point. http://tinyurl.com/o9mxa69 And the nut will have an
inner flare to the tip to mate the bell of the tube.

When I was wrenching, I only saw the Japanese style, not the Euro.
http://tinyurl.com/pnhvbdo Which is the one you're working on?

--
However beautiful the strategy, you should occasionally look at the results.
-- Sir Winston Churchill