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Smoothing broaches

Yes, they are for burnishing a hole in a brass plate. They have have the same taper as 5 sided cutting broaches so they are intended to polish a pivot hole after fitting a new bush and cutting to size. Generally used by watchmakers.
 
So just to smooth the intersection of a countersink and a through hole would be a correct application? I have a print that calls for deburring an intersection of a .156 hole (drill point ) and a .074 hole by using a smoothing broach. I've never heard of it. Material is Monel, so wondering how well it will work. Only a few pieces of tooling, so no long term use.
 
Dunno. I think there might be a terminology problem. Not sure that a watchmakers smoothing broach is a good deburring tool. Clockmakers use oilsink cutters to debur/blend the edges of bushings.
 
I'm not into clockwork, but what I just now learned are "oilsink cutters" are frequently sold for use as micro deburring handtools.

Looking at the photo and ad copy of the smoothing broaches linked in the first post of this thread, they look like flute-less burnishing tools. They are obviously made to the same taper as clockmaker's cutting broaches, but apparently have a pentagonal cross-section with a substantial negative rake at each apex/edge. From what I found elsewhere, some burnishing broaches are made with a circular cross-section and grained lengthwise with about a 120 grit abrasive after hardening, to give them just a slight action.
 
Looking at the photo and ad copy of the smoothing broaches linked in the first post of this thread, they look like flute-less burnishing tools. They are obviously made to the same taper as clockmaker's cutting broaches, but apparently have a pentagonal cross-section with a substantial negative rake at each apex/edge. From what I found elsewhere, some burnishing broaches are made with a circular cross-section and grained lengthwise with about a 120 grit abrasive after hardening, to give them just a slight action.
I believe the technical name for them is planishing broaches. Or used to be, back in the olde dayes. Might get more hits for that term ?
 
Looks like a small ball end mill turned by hand would do the trick similar to an oilsink cutter would do. That's where I'm going to start. The smoothing broaches look like you would need plenty of clearance or a through hole to use them.
 








 
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