Furnace Grate Plug

This is a plug for a furnace grate. It's my first major 3D printing success. Designed in TinkerCAD.

It's been suggested here that the plastic shouldn't be aligned perpendicular to the stresses: http://www.reddit.com/r/3Dprinting/comments/1eoabn/3d_printing_noob_this_is_my_first_big_win/