Busch Precision Parallel Straight Edges - BSB-6108; Busch Precision Parallel Straight Edges - BSA-6100; Busch Precision Cast Iron Parallel Straight Edge, Size 1" x 2" x 24" - BSB-6102; Busch Precision Cast Iron Parallel Straight Edge, Size 1.5" x 3" x 36" - BSB-6103; Busch Precision Parallel Straight Edge … Ht. Two numbers Grade 1 parallel straight edges of the same length can be offered as matched pair, at extra cost, ensuring equality of overall depth within the tolerance on parallelism for the respective length of straight edge. You can also make a parallel straight edge by mounting 4 small pulleys on your bar and threading it in an H pattern, going from lower-left, up to then across the straight edge to the right side and continuing up to top-right, across to the top left, down to the straight edge … Weight, lbs. Tolerance per Foot : … Other articles where Parallel straightedge is discussed: drafting: Equipment: protractor, and compass; the parallel straightedge is an alternative to the T square. For those who work with a … Actual dimensions of straight edges … Every Mayline parallel ruling straightedge bar begins with a durable black phenolic laminate base where a transparent blade is inset for see-through registration and fine line quality. Level machinery, check surface flatness, and scribe work positions. The drafting machine, introduced about 1930, allows a straightedge to be moved while maintaining any desired angle between it and the edge … Parallel Straightedges . Lg. Wd. The top and bottom faces are precision ground within 0.0001" per 12".