Related Object Info
Barth's cutting speed slide rule
Wood rule with four slides, faced with off-white paper on top. The top and bottom slides are fixed; the second and third slides move to left and right.
Printed on the bottom edge of the top slide is a scale for "CLASS NUMBER OF MATERIAL," carrying values from 0 to 40. On the top edge of the second, moveable slide are two arrows pointing towards the top slide. The left-most arrow is labeled, "CAST IRON"; the right-most arrow is labeled, "STEEL."
On the bottom edge of the second, moveable slide is printed a scale for "CUTTING SPEED PER MIN.," with values ranging from 10' to 400'. The third, moveable slide is divided horizontally into sections for "STEEL" (on left), and "CAST IRON" (on right). In each section are two scales, stacked vertically. The top scale, for "FEED," carries values descending from 0.25'' to 0.01''. The bottom scale for, "DEPTH OF CUT," has values ranging from 1/32'' to 2''.
The fourth, fixed slide is likewise divided horizontally into sections for "STEEL" (on left), and "CAST IRON" (on right). In each section, the top edge of the slide is printed with a scale for "LIFE OF TOOL," carrying values descending from 2 HRS. to 10 MIN.5'' 0.01''