Glossary
Short answers to basic questions about sheet metal.
What is sheet metal?
Sheet metal is thin, flat metal made by rolling. It is supplied as sheets or wound into coils. We work with steel sheet that is galvanized or colour-coated.
What is trapezoidal sheet?
Trapezoidal sheet is sheet metal formed into regular ribs. It is named after their cross-section, which is a trapezoid. This shape makes it stiffer than flat sheet of the same thickness.
It is used for roofs and facade cladding on industrial buildings, family houses, garages and farm buildings. We make trapezoidal sheet from coils in lengths of 0.1 – 12 m.
What do T18, T29 and T50 mean?
The letter T stands for trapezoid and the number after it is the profile height in millimetres: T18 is 18 mm high, T29 is 29 mm and T50 is 50 mm.
| Profile | Height | Covering width | Thickness |
|---|---|---|---|
| T18 | 18 mm | 1,072 mm / 804 mm | 0.40 – 0.80 mm |
| T29 | 29 mm | 1,029 mm / 735 mm | 0.40 – 1.00 mm |
| T50 | 50 mm | 1,040 mm / 780 mm | 0.40 – 1.00 mm |
Covering width is given for a coil 1,250 mm and 1,000 mm wide. All dimensions and drawings are on the trapezoidal sheet page.
What is the difference between trapezoidal and corrugated sheet?
The difference is the shape. Trapezoidal sheet has ribs with straight sides and a flat top, while corrugated sheet has rounded waves. Our lengths differ too: we make trapezoidal sheet up to 12 m long and corrugated sheet in a standard length of 2,000 mm.
What is corrugated sheet?
Corrugated sheet is sheet metal with regular rounded waves. We make it with a transverse wave from flat galvanized sheet, 0.50 – 0.55 mm thick. The standard length is 2,000 mm, and shorter lengths are available by agreement. See flat and corrugated sheet.
What is flat sheet?
Flat sheet is straight, unformed sheet metal, usually cut into panels. We make it 0.40 – 1.5 mm thick, 1,000 – 1,250 mm wide and from 10 to 3,000 mm long, or to the customer's requirements. See flat and corrugated sheet.
What is galvanized sheet?
Galvanized sheet is steel sheet with a layer of zinc, which increases its resistance to corrosion. Read more about the materials we work with.
What is colour-coated sheet?
Colour-coated sheet, also called lacquer-coated sheet, has a coloured surface finish in RAL colours. We make trapezoidal sheet and tinsmith products both galvanized and colour-coated.
What is a sheet metal coil?
A coil is a long strip of sheet metal wound into a roll. It is the starting material from which flat sheets are cut and trapezoidal sheet is formed. If you have your own coil, we can process it: coil reprocessing.
What is covering width?
Covering width is the width a sheet actually covers once laid. Neighbouring sheets overlap, so it is smaller than the total width of the sheet. For example, T18 has a total width of 1,125 mm and a covering width of 1,072 mm. Use the covering width when working out how many sheets a roof needs.
How much does trapezoidal sheet weigh?
The weight depends on the profile, thickness and sheet width. At a thickness of 0.50 mm it is roughly:
| T18 | 4.66 – 4.98 kg/m² |
|---|---|
| T29 | 4.86 – 5.44 kg/m² |
| T50 | 4.81 – 5.13 kg/m² |
Weights for other thicknesses are in the tables on the trapezoidal sheet page.
What are tinsmith products?
Tinsmith products are formed sheet metal parts used to finish roofs and facades, such as edgings, window sills and valleys. We make them from galvanized and colour-coated sheet. The full list is under tinsmith products.