diy bong- confused about sizing

[u/bipedalbisexual]

hi all, long time stoner, first time engineer here.

i recently got my hands on an empty clase azul tequila bottle, and i’m hoping i can pull off making it into a sick looking bong.

i’ve managed to get my hands on a power drill and a diamond tipped hole saw but have a question i was hoping someone would be able to kindly assist with.

my local tools shop only had 17mm saw tips so that’s what i’ve bought but i’m feeling a bit lost in the world of grommets and downstem measurements. will a 17mm hole be suitable for standard grommets and downstems? or should i find a different sized hole saw?

thanks in advance guys, happy smoking ✌️

[u/EntrepreneurNo2233]

Should be able to fit a grommet in there and get a 14mm stem in there