Tube sizing

[Jim Burr]

If I wanted to buy brass tubing for a blank, say a Sierra/Mesa blank..would I buy a size based on the drill size, 23/64th, I think or is there another measurement to consider?
For future reference..what measurement determines the tube size?
Thanks guys!:biggrin:

 

[navycop]

Give this a look. It might help. http://content.penturners.org/library/general_reference/bushingsandtubes.pdf

 

[mredburn]

You can order the Sierra tubes from Exotics. Of course it depends on what type of pen your wanting to build. THere are several vendors that sell brass tubes in 10 inch lengths. 7mm,8mm,3/8, and 10mm. Exotics sells several sizes of kit replacement tubes that you can use to build your own pens. K&S engineering sell brass tubes in several sizes if you want to go that route.

 

[Dorno]

All the info you are ever going to need is on that file that mike has attached it is so handy and congratulaions once again to those who compiled it.

Cheers ian

 

[beck3906]

Be careful if you're considering buying brass tubing like what you find in hobby shops and different places. The critical dimension is the thickness of the tube wall. Most hobby shop brass tube is thicker than tubes used for pen tubing.

I tried this years ago and ended up cracking turned blanks when I tried assembling the pen. Because the tube walls were thicker, the components were much tighter and ended up cracking the blank when I tried forcing the component in.

 

[azamiryou]

If you are using kit parts, you need to match the inside diameter (ID) to the kit parts. For most kits, the outside diameter (OD) doesn't matter*, you just have to have a drill bit that makes the correct sized hole. I have no idea how close the ID tolerances need to be, but I'd think pretty close for press-fit parts. The ID could probably be a hair bigger if you don't mind having to glue the pen parts in.

*If the kit includes parts that press onto the outside of the tube, such as the center band in a "no tenon (NT)" Euro, the the OD is important, too.

 

[mredburn]

I make all my parts to be epoxied in. There is a large amount of freedom in bieng able to try the fit and finish before final assembly. Yes If you use the hobby shop tubes you will need to either sand or drill the tube out a little or turn down the press fit part and glue it in or both. Or you can make your own caps and centerbands out of other materials and throw the kit parts away. You can use that as a small step towards custom building your own pens.

 

[renowb]

Yes, this is very informative. Has it been upgraded with the new kits?

Give this a look. It might help. http://content.penturners.org/library/general_reference/bushingsandtubes.pdf