1.1 x 0.9 mm

Two dimensions that tell you everything about the tube

The outside diameter measures 1.1 mm and the inside one 0.9 mm, so the wall is a tenth of a millimeter thick. The material is brass, which cuts, bends and solders well and which, unlike plastic, takes a load without sagging even in a thin section. The drawn surface is smooth and, once degreased, holds paint with no further preparation.

A range that fits into itself

The whole range of sizes goes up in steps of two tenths of a millimeter and the wall stays the same. Because of that, the outside diameter of a smaller size matches the inside diameter of the next larger one exactly, so the pieces can be slid into each other like a telescope. That principle comes in for stepped barrels, for extending antennas, for the hydraulic rams of landing gear or for making a reinforced root where a thin tube on its own would not hold. In the larger sizes the muzzle of a weapon with a hint of a bore is suggested the same way.

How to work with it

Do not cut it with pliers or with scissors, because the end would be squashed into an oval. The best way is to score the circumference with the tip of a knife while rolling it slowly on a surface and then snap the piece off, or to use a small saw and true the burrs up with a file. Clean the inside out with a drill so that the muzzle stays round. It is glued with super glue, but a more dependable joint comes from soft soldering. Degrease the surface before painting and apply a primer intended for metal, otherwise the film will rub off during assembly. This size takes a bend, but only over a smooth curve; at a sharp kink the wall collapses inwards and the section flattens.