Video – Using a square
The video shows a builder using a try square and a combination square. He shows how to mark out a piece of timber at:
- 90 degrees with the try square
- 90 degrees with the combination square
- 45 degrees with the combination square.
He also shows how to check that a piece of timber has been cut square and straight by using the combination square and checking for light showing through gaps between the edge and the square.
The audio for the video is as follows:
'So, one of the ways we can use the try square is to mark a line at 90° to a piece of timber. So what we do in this case is we need to mark sure we a nice flat straight edge of the timber, we put the edge of the try square against the timber, hold it nice and tight, hold it in position, and then mark our line. What we then have is a line which is at exactly 90° to the side of the timber. The other way that we can do that is using a combination square. It also allows us to mark a line at 90°. Once again hold the square flat against the edge of the timber, hold it firmly, mark our line.
The benefit of the combination square is you can also mark a line at 45°. To do that you place this edge here of the square against the piece of timber, in the position you want to, hold it firmly, mark your line. What you have then is a perfect 45° angle here.
One other use of the try square is to check if something is already square, for example if we wanted to check if this angle here on this piece of timber was exactly 90°, we could hold the square flush against the edge of the timber, have a look along the top edge and check if there's any gaps there. You'll notice a gap by the fact that there will be light shining through.
If there's no light shining through we know that piece of timber's been cut at exactly 90°.'