Square Manhole Covers Item No Clear Opening (A) mm Over Bass (B) mm Depth (C) mm Loading ton S-2001 640 800 34 1.5 S-2002 547 700 41 4 S-2003 540 700 27 1.5 S-2004 470 630 38 4 S-2005 490 605 25 1.5 S-2006 445 535 24 0.2 S-2007 300 375 18 0.2 S-2008 215 280 20 0.2