- Made generally as per JB/T7974-1999
- Made from close grained plain cast iron conforming to Grade FG:220 of IS: 210 (equivalent to GG20/ FT20 / 30-A). Higher grades also offered on request.
- Castings stress relieved to relieve internal stresses.
- Sizes upto 2000 x 1000 mm offered in four Grades of flatness accuracies viz Grades 0, 1, 2 & 3 as stated in table.
- Hand scraped surface finish for Grades 0, 1 and 2 flatness accuracies & smooth machined / rough ground / scraped surface finish for Grade 3 flatness accuracies.
- Rigidity requirements as per IS: 2285 ensured in case of Surface Plates of Grades 0, 1 and 2 only.
- Flatness determination done by grid method as per clause 4.3.1 of JB/T7974-1999 China standards on Engineering Metrology "Methods of Testing Straightness, Flatness and Perpendicularity".
- Flatness accuracy checked by Electronic level. Computer print out of the contour of top working surface is furnished.
- Plates up to 630 x 630 mm provided with handles for lifting. Larger plates provided with cored holes in peripheral ribbing for lifting by mechanical means.
- Column type C. I. Floor stands or M.S. Fabricated stands with leveling screws supplied at extra charge, if required.
- Special features like grid slots for location, tapped holes and T-slots can be provided on working surface, if required.
-
Cast iron bed plates Precision: According to the national standards measurement examination regulations execution,
respectively is 1,2,3, fine polish.
-
Specification (mm) Flatness tolerance (um) Grade1 Grade2 Grade 3 Finihs plane 400x400 12 24 600x400 14 28 800x500 16 32 80 900x600 16 32 80 1000x750 18 36 90 1000x1000 20 39 96 1500x1000 25 48 120 2000x1000 26 52 129 2000x1500 56 140 2000x2000 60 152 230 2500x1500 68 168 248 3000x1000 174 248 3000x2000 184 275 3000x3000 210 300 4000x1000 210 300 4000x2000 219 310 4000x3000 240 360 5000x2000 255 375 5000x3000 287 420 6000x2000 293 430 6000x3000 308 460 8000x2000 370 520 8000x3000 382 570