They've always mystified me too. Something to do with focusing the gas to allow the torch to be further from the workpiece than normal (which sounds like a good idea for DIY). But not the standard stuff you normally be given when you ask for TIG torch bits.Are there any pictures of gas lens'?
Sounds like something we all need then.
I'l look into it.
Can i use my normal ceramic's though? I.e. my number 5 etc.