Body Tube Size Guide

Jeff Roberts (Luke Strawwalker or OL JR on The Rocketry Forum)
put together a Body Tube Size Guide at:
http://forums.rocketshoppe.com/showthread.php?p=88407

Print this one out and keep it handy!
"BT" refers to the Estes sizes. "Series" (ST) refers to the older Centuri tubes.

Typically, most vendors sell the Estes BT tubes.
All the Centuri ST tubes are available from Semroc.
Some (not all) ST tubes are sold by BMS and ERockets.
Quest tubes are available from Quest only.

TIP: When you start keeping accumulated tubes in your spare parts box, write the tube name on the inside lip in pencil.
It's easy to get them mixed up - 
Quest 20mm tubes are too close to a BT-30
The Quest 40mm is a slip fit in the Estes BT-60.
The Centuri Series 10 is almost the same size as an Estes BT-50.

Carl from Semroc added this:
The Estes BT-56 is the same as the Centuri ST-13
The Estes BT-67 is the same as the Centuri ST-20
The BT-5 and the ST-5 are interchangeable

Bernard Cawley posted:
Also ST-9 and BT-50 tubes have identical inside diameters....so mounts, couplers, and for all practical purposes nose cones for one also fit the other. ST-9 has thicker walls than BT-50, yielding a slightly heavier but more robust airframe.

Thanks Bernard! I didn't know the ST-9 had the same interior diameter. 
Next time it comes up, I can replace those "crimpable" BT-50 tubes with the ST-9s!