Please note we are currently unable to dispatch to Northern Ireland.

Please note that grilles and louvres made to order have a current lead time of 10-12 working days. We have been informed by the manufacturer that this is due to a material shortage. We apologise for the inconvenience this may cause.

450mm Width 100mm Depth

Ventilation Ducting  | Rectangular Ductwork | Square to Rounds Pattern Only | 450mm Width |  450mm Width 100mm Depth

Square to Round - Pattern Only - 450mm Width 100mm Depth

Note: this product is the pattern only. Fully fabricated square to rounds are available here..

The pattern will be supplied in two halves and will include a 50mm straight section on the square end.

Please use the drop down menus below to select the diameter of the round end and the style. There is also the option to include the spot weld laps. When we manufacture square to rounds we always include these laps to join the two halves and to enable the spigot to be attached. Depending on how you intend to use the pattern they may not be required; for example if it is to be used as a template for a heavier gauge steel that you intend to fully weld you won't want the laps.

If you wish to fine-tune the size please use the 'Other info' box below. Unless requested otherwise, the length of the square to round will be determined by us in accordance with standard ductwork specification.

Note that with offset square to rounds the flat side will correspond with the 'width' side. If you require the other side to be the flat side i.e the 'depth' side as shown in the drawing, go back and make the width the depth and vice-versa.



Include laps?

Any other info or specific requirement (optional):


Square to Round - Pattern Only - 450mm Width 100mm Depth

Your Basket


View BasketCheckout
Best Sellers

100 dia 90° Pressed Bends with Seals

100 dia 90 Pressed Bends with Seals


600mm 30x30 Cantilever Support

600mm 30x30 Cantilever Support


PU S1 Clear Extraction Hose 10m Length

PU S1 Clear Extraction Hose 10m Length

M8 Back Plate Threaded Rod Hanger

M8 Back Plate Threaded Rod Hanger


100mm dia Chrome Exhaust Valve

100mm dia Chrome Exhaust Valve