Features0.19 in (5 mm), 0.25 in (6 mm) and 0.38 in (10 mm) steel plateEnds are 0.38 in (10 mm) steel plate to provide a minimum of 3-1/2 full threads for conduit sizes through 2 in (51 mm)Class II enclosures must have minimum of 3-1/2 full threads at all conduit entrancesNEMA requires conduit entrances to be in top and/or bottom of enclosureTapped holes for conduit should have tapered pipe threadsCovers are 1/4 in (6 mm) thick to allow mounting of NEMA 9 pushbuttons and pilot lights, which require threaded holes (3/4 to 14 NPSM thread)Heavy duty cover hinges on enclosures when "A" is 20 in (508 mm) or moreFiber gasket, mechanically attached to cover, assures dust tight enclosureWeldnuts or collar studs provided for mounting optional panel