Sizes range from 30mm to 150mm diameter in 10mm increments
sizes are quoted inside diameter in millimeters.
To establish the outside diameter add 5 millimeters to each size.
Eg;- 30mm ID = 35mm OD.
120mm ID = 125mm OD
ducting is made from electro galvanized steel sheet metal with the base
thickness 0.3mm thick
We use a custom made former to produce our standard lengths
or to your custom lengths
We also make these and they are 3mm to 4mm larger than each standard size and
screw on like a bolt and nut.
Plastic end caps are available also and these push into the end of each standard
These can be fixed to the form work to hold the duct in place or to seal off the
end to stop concrete from getting in the duct.
They are available for each size up to 140mm.