tender for aluminium chequered sheet for coaching stock size: 3310 mm x 880 mm x 2.03mm (height of elevated ridges is not included ). height of elevated ridges-0.89+/- 0.2mm. material and specification : rdsos str no-c-8217 (rev.2), of sept ., 2013. remarks:for pattern of chequered sheet clause-4.3 of above specification has to befollowed .