I drill 1mm as deep as needed to get the gas to the jet: then the jet itself is 1~3mm through the final wall of brass. A good set-up will drill 5 holes before I lose the drill. (They are not strong enough to cope with the break-through - and the lathe gives very little back-pressure "feel" at that size of hole). A bad set-up won't drill. The jets are typical 7mm long, hex brass either 3/16" (3/16" x 40 thread) or 1/4" AF. (for 1BA) - With thread to suit the jet holder. (1BA is used in UK as a standard by some suppliers).
I buy no 5 (0.20mm) and no 3 (0.15mm) jets - cheaper than drills for me! But I mostly use no 8 (0.20mm) or 12 (0.30mm) jets - or larger number drill sizes - for my ceramic burners.
It's just a bit of fun (challenge?) - to keep me from following the misses around the house!
K2
I buy no 5 (0.20mm) and no 3 (0.15mm) jets - cheaper than drills for me! But I mostly use no 8 (0.20mm) or 12 (0.30mm) jets - or larger number drill sizes - for my ceramic burners.
It's just a bit of fun (challenge?) - to keep me from following the misses around the house!
K2