Lee Valley Magnetic Straightedge
The magnetic straightedge combines a chrome-plated steel rule with a magnetic body to produce a simple, yet highly versatile, drawing aid. Each of the seven slots is bottomed with a pair of 3/8" rare-earth magnets, which securely hold the rule in place, while allowing it to slide freely. The leading rabbet allows the rule to be positioned with an offset.
The aluminum body has slots at all the common drafting triangle angles: 45°, 30° and 60°, etc., in addition to 90° for use as a square.
This tool is not a precision engineer’s square. A small clearance between the slot and the rule is needed, but the deviation is guaranteed to be no more than 2° in any slot.
As a straightedge: The tool can be confi gured as a straightedge by placing the rule in the rabbet against the three magnets. In this position, the body lifts the rule off the paper slightly, preventing felt pens from bleeding ink onto the paper.
As a T-square: The central 90° slot allows the tool to be confi gured as a small T-square. The graduations and adjustable projection mean it can also be used to draw parallel lines.
As a triangle: In addition to the linear graduations, the rule has also been etched with the following angular graduations: 30°, 45°, 60°, 90°, 120°, 135°, and 150°. These angles correlate to the slots in the body. To determine which angles are being provided by a chosen slot, place the rule in the slot and slide it until the etched line is parallel to the body.
As a depth gauge: The three magnets in the rabbet allow the tool to be used as a depth gauge. Either end of the body can be used, as can either linear scale. The 90° slot can also be used for the same purpose.