I think it could be related to breach, too, though that's just my opinion, not borne out by the etymologies.
1. Mach.an elongated, tapered, serrated cutting tool for shaping and enlarging holes.
2. a spit for roasting meat.
3. a gimlet for tapping casks.
4. (in a lock) a pin receiving the barrel of a key.
5. Also,broach' spire". Archit.an octagonal spire rising directly from a tower without any intervening feature.
6. Masonry.a pointed tool for the rough dressing of stone.
7. brooch.
—v.t.
1. to enlarge and finish with a broach.
2. to mention or suggest for the first time: to broach a subject.
3. to draw (beer, liquor, etc.), as by tapping: to broach beer from a keg.
4. to tap or pierce.
5. Masonry.to shape or dress (a block of stone).
—v.i.
1. Naut.(of a sailing vessel) to veer to windward.
2. to break the surface of water; rise from the sea, as a fish or a submarine.
From: http://dictionary.infoplease.com/broach
