This aluminum hard line equals the following equivalent 1:1 size at each scale.

1/25 scale = 1 1/2"
1/16 scale = 15/16"
1/12 scale = 3/4"
1/8 scale  =  1/2"

Depending on your scale, typical uses are coolant, fuel and oil lines.  Also, at larger scales, A/C lines to/from the compressor and fuel supply and return lines to/from the fuel cell or gas tank.

This solid core aluminum is easy to bend and shape to your installation. Drill the end out to simulate a hollow pipe.

Use Pro Tech Fittings sized at .060. These will have to be drilled out slightly.

We're about half of the price you'll find elsewhere.
Each package contains one coil of .059 x 18"