Sea-Tac nut and bolt...I've even ordered crankshaft bearing from them once when the dealer was going to have to order it from Japan.
They have different locations in Seattle area - I think its a different company than seattle nut and bolt - and don't think they have a website...but they can get anything fastener related, if you're looking for something special, or need something in bulk...or if in and/or around Seattle area.
Sea - Tac Nut & Bolt Inc
928 S 140th St
Burien, WA 98168