Nipples - double square or normal?

Just get standard ones !

Double square are stronger, but weigh a bit more. You can usefully use longer spokes if that floats your boat but isn't actually needed. I prefer building from the inside and you can buy tools to do that both for a drill and for hand that work really well with DS nipples, but if you plan just to build with a spoke key, then unless they're cheaper they don't offer all that much.

Sorry OP can't help, but get the best you can for future adjustment and yes Brass.

BTW ...Why are they called nipples and why are other nipples called nipples, answers on a postcard;)

The last wheels I built I used the Sapim double-square. I found it a bit easier and faster to insert and then turn the nipples from the outside using a three-pronged spoke wrench than using a spokey (4-sided).

I can certainly see why machines prefer them.

I used the Sapim aluminium ones; they claim to be as good as brass. Not been used long enough yet to know if this is true.

Thanks all, suspicions confirmed - I'll go with the normal ones.

I do have a square nipple driver for my fancy (/stupid) internal nipple road wheels and agree it's nicer to use, but I can live with using a Spokey for the weight saving.

Just built a set of wheels using double square nipples using a T handle double square driver

So much nicer to build than when using a spoke key (normally use a Spokey Pro key) espcailly when building with straight pull spokes and you need your other hand for holding the spoke clamp tool in place to stop them spinning as you tension the spokes

Last wheels I built (and the next one coming soon) were sealed rim bed so it made no odds, it was all done with a spoke wrench on the outside of the rim.

I've always built with brass nipples though.

BTW …Why are they called nipples and why are other nipples called nipples, answers on a postcard;)

After pipe nipples. Next question, why are pipe nipples called pipe nipples?

the end drive nipples from Sapim and DT Swiss are so much nicer to work with.

Which is probably a major factor if you do it every day, but for a single wheelset, it really makes little difference.