Hi Reuel
From somebody in the EU; jigs in the UK have long required a 30mm guide bush and use a
1/2in (12.7mm) cutter - European mainland jigs seem to require the 30mm guide bush, but a 12mm cutter (except Festool jigs). Here we generally see only the UK market (1/2in cutter) jigs. Neither combination is problematic for us as regards tooling. Take a look at this listing from
Wealden Tool - product TX1412.7M Ø12 .7 (1/2in) x 52mm long is TX1412M is Ø12 x 52mm long, both on 1/2in shanks. Other manufacturers offer similar cutters, although I personally prefer the KWO Versofix removeable-tip (single flute) cutters like the
K69420 for worktop mason's mitre joints. Whilst that listing doesn't show it, KWO also sell a Ø12 x 50mm long Versofix and they accommodate 12mm (metric) shanks in addition to the 1/2in British/American "standard". Because of this
de facto standard here in Europe new 1/2in routers are pretty much all delivered with a 30mm guide bush in the box
These 50mm cutters are all very well, but more recently we've also had to contend wuth "super thick" honetcombed worktops at 60mm. At present the only people doing cutters for them appear to be Trend and Titman
I don't know if KWO (H Schumacher & Sohn) has an outlet in Australia, but they now have a very good distributor in the UK who's web site is
here. Maybe they could tell you about Australian distribution, if any, should you be interested
Regards
Phil