What size is the rear axle bolt?

I have to replace my rear axle due to cross threading it while tightening the chain. Anyway once that happened, I could only screw or unscrew the axle bolt a little and ended up rounding off both the right nut that comes off and the left one that is attached to the axle. Eventually, I had to file down the nuts and to to large cresent wrenches and heat to get the nut off. While I wait on the axle to be sent, thought I would buy a long ring wrench to hold the left side more securely so it won't slip as I loosen or tighten the rt. axle nut...however I don't now the size any more. It appears the right nut is 19 mm. and the nut attached to the axle that you have to hold to keep it from turning is 14 mm. but I'm not sure any more since they are filed and rounded off on the old axle. Anyone know these sizes? Thanks