A-A-52300
Style 2. The outer row of figures shall read clockwise from zero to 90 degrees; 90 to zero degrees; zero to 90 degrees; and 90 to zero degrees, starting at the left in line with the horizontal axis. The inner row of figures shall read clockwise from zero to 360 degrees, starting at the left in line with the horizontal axis.
Materials:
Material shall be as specified herein.
Brass. Brass shall be a flat rolled sheet up to and including 0.188-inch in thickness. Brass sheet tempered to half-hard shall be acceptable.
Plastic. Plastic protractors shall be made out of acrylic, methacrylate, or any other plastic material that provides similar durability.
Graduations, letters, and numbers. All graduations, letters, and numbers shall be cut, stamped, printed, photoprinted, etched, or indented. Graduation lines shall be uniform, shall be between 0.004 and 0.010-inch wide, and shall have a tolerance of ± 5minutes of arc. Graduations, letters, and numbers shall not project above the surface of the brass or plastic. Unless otherwise specified, cut, stamped, etched, or indented graduations, letters, and numbers shall be filled with permanent black ink or paint.
Degrees. The graduation marks for protractors reading in degrees shall be of not less than four lengths; the shortest length denoting 0.5 and the longest denoting each 10-degree increment. Graduation marks shall be numbered every 10 degrees in two rows of figures. The 0.5-degree graduation is not required on 4-inch protractors.
Crossbar. Each protractor shall have a crossbar formed by removing a semicircular segment or segments from the protractor so that the width of the crossbar and the section between the concentric arcs are equal. A vertical line shall be formed on the crossbar, intersecting the horizontal axis, to indicate the vertical axis of the protractor.
Brass protractors. Brass protractors shall be flat and shall be between 0.03125 and 0.0625-inch thick except that 4-inch protractors shall be more than 0.015625-inch, but less than 0.0625-inch thick. The horizontal axis shall be along either edge of the crossbar. A vertical line shall be formed on the crossbar to indicate the vertical line shall be formed on the crossbar to indicate the vertical axis of the protractor. The line shall be formed by the same method as that used for the graduations.
Plastic protractors. Plastic protractors shall be flat and shall be between 0.0625 and 0.125-inch thick. Graduations shall be on the bottom surface of the plastic and shall be readily distinguishable through the thickness of the plastic. Letters and numbers may be on either surface of
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business