Polished stainless bolts look good on our cars. The cost one polished bolt can discourage a builder from using them. I checked the cost of some 1/4 -28 1 1/4 inch carriage bolts polished stainless steel about 3.00 a bolt. I bought what I needed un polished at 38 cents a bolt and spent a small amount of time with bolts chucked in hand held drill and using sand paper to 2500 grit paper had what I needed done in short time . They are really bright and shiny. In looking for 2000 grit sand paper found a automotive paint shop that sells to automotive body repair shops. They have all the goodies anyone would want on display. Air tools hand tools and candy paint are there. Also the needed sand paper. Cost of doing the bolts needed was about 70% cheaper than buying pre polished bolts.