Offered in two types viz. Bow shaped or Camel Back type and I-Section or Parallel type, made generally as per IS-5268- 1991.
Bow shaped Straight Edges are provided with pads on their bow for support Engineer Level.
Made from close grained Cast Iron Castings conforming to Grade FG-220 of IS-210. Casting duly stress relieved.
Offer in hand-scraped finish to various Grades.
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 accuracy Straight Edges.
Flatness of side faces: Any 300 mm length flat within 25 microns for Grade-0, Grade-1 and 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 Grades-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 over any total length.
Supplied with rexine cover for protection of working surfaces.