Abstract: A tool for selectively marking a surface in specific desired increments for use in a variety of mechanical arts. The tool has a ruled face and indicates selected increments by illuminating light emitting devices corresponding to the locations to be marked.

Abstract: An apparatus for measuring compound angles. This apparatus makes use of the standard T-bevel square, which is capable of measuring only a single angle. The invention is a compound angle blade with a split collet joint. The compound blade attaches by replacing the bolt of the T-bevel with fastening means attached to the split collet joint of the invention. This fastening means secures both the compound angle blade and the standard T-bevel square blade. The split collet joint which is attached perpendicularly to the main body of the T-bevel moves in a 360 degree radius parallel to the main body of the T-bevel. The compound angle blade is capable of rotation in approximately a 180 degree radius relative to the split collet joint. The combination of the rotation of the split collet joint and the compound angle blade allows for compound angle measurements both perpendicular and askew relative to the angle of the standard T-bevel. The angles of both blades are fixed by the same fastening action.

Abstract: An extendable level consists of two interslidable parts having a track and slide strips in a simple construction, wherein there is always a planar relationship between the level edges. The slidable extension rests within the length of the main body when unextended.