BB replacement, do I need a lock ring?
 

I'm rebuilding an old 10 speed into a fixie for my GF. It originally had Cotter pin Cranks, but I'm going to replace the BB with square one and also put on some bare nuckle cranks. I bought a 73x113 shimano sealed cartridge BB, from a store and it fits great. Now I'm putting it in and wondering if I did it correct. It fits snuggly with all the parts included. I don't know whether I need to put on the old lock ring from the cotter pin cranks, or if this BB doesn't need one. I feel like the left side is naked without a lock ring. but It won't thread on either side?
a quick answer would be greatly appreciated.
kirk

No Lockring needed. As long as you have everything Snugged up properly the interference fit will keep it good.

thanks awesome, thats what i was guessing