• Micro-Flat Datums Private Limited

Straight Edges, Cast Iron

Microflat cast iron straight edges are widely used for setting and levelling machinery and for checking and spotting bearing surfaces during hand scrapping operations. Properly supported, they may be used with various indicating devices to check surf flatness of large machined areas like surface tables, machine tables and beds, machine ways, etc. Salient features: offered in two types, viz., bow shaped or camel back type a I-section or parallel type, made generally as per IS-5268-1991; bow shaped straight edges are provided with pads on their bow for supporting engineer's level; made from close grained cast iron castings conforming to grade FG-220 of IS-210; casting duly stress relieved; offered in hand scrapped finish to various grades, i.e., grade-0, grade-1 and grade-2; standard sizes, dimensions, flatness a parallelism tolerances, etc., stated in the table; high spots uniformly distributed; proportion of bearing area of the working surface not less than 20% for grade-0 and grade-1 and not less than 10% for grade-2 straight edges; flatness of side faces – any 300 mm length flat within 25 microns for grade-0 and 1 within 50 microns for grade-2; squareness of working surfaces and side faces when checked with side face laid on grade-1 surface plate, for grade-0 and 1 – within 8 microns per 25 mm, for grade-2 – within 15 microns per 25 mm; parallelism of side faces, for grades 0 and 1 – not exceeding 30 microns per 300 mm and 60 microns over total length, for grade 2 – not exceeding 60 microns per 300 mm and 120 microns for over any total length; supplied with rexine cover for protection of working surfaces; and actual dimensions of straight edges may be more than those stated.