The speed square was invented in 1925 by albert swanson.
Smallwood roofing square instructions.
Home construction tools steel aluminium squares roofing rafter square smallwood 390 390b black anodised aluminium rafter square 620 x 450 90 96.
Look on the first line of the roofing square to determine the length of common rafters per foot run.
If the span in this example is 9 75 m 32 feet multiply 35 28 cm 13 89 inches by 4 8 m 16 feet and you get 565 cm 222 24 inches or a rafter length or 5 65 m 18 52 feet.
For rafters made in 2 x 6 s or larger lay the square body flush with the bottom edge of the rafter and mark along top edge of the square body.
Swanson was a carpenter in a small town outside of chicago.
Finance subject to status.
As a protractor for easily finding and marking various common angles especially roof rafter pitches and angles for stair stringers the vertical supports on a stairway.
A carpenter s framing square includes some tables stamped right into the tool itself.
Purlin housing angle on the side of hip or valley use the value on line 6 by moving the decimal point one place to the right.
As a miter square for accurately marking 45 angles and.
Rebuilding america one square at a time.
In our example using a 25 common pitch use 2 708 mm on the tongue of the square and 10 on the body.