From left to right....deep bowl work, venturi/near seat work, roof to guide shaping. For the iron factory crap I use lefty there and round/broaden the runner corners 'dead air in tight cormers' and get between the wall and guide-big flow gains
You could use them for your choice of course..that's just where I'd use them...and I like dbl cut versions but do use those too, the 1/2 head diameter is great for between the guide/wall as said.
