Floats versus rasps versus files

[Greg Portland]

So, I have a few traditional rasps and microplanes. What functionality does a float provide that a rasp does not? Beyond the obvious tooth geometry, it appears that floats can be sharpened with a file but rasps are sharpened with a mild acid solution (i.e. floats are softer metal)?

Is there anything wrong with using a file on wood? I've used a cheap flat or mill file on wood and it seemed to do OK (some clogging).

[John Coloccia]

Nothing is wrong if it works :) Files are used on wood all the time. Generally, floats have perpendicular teeth and/or curved teeth...files are generally angled...floats generally have deeper teeth....files not. Geometry is generally a bit different. Floats tend to be a little more aggressive. Floats tend to have straight sides, and files tend to be curved. There are probably other differences I'm not articulating...I know a float when I see it, and I know a file when I see it.

They're all useful for woodworking. Don't get hung up on terminology. For example, the famous "Vixen" file (great for aggressive aluminum stock removal) would generally be called a float if you use it on wood. As another example, I would probably classify the Iwasaki carving "files"
as floats....but everyone calls them files.

The main difference in my mind is that floats tend to cut and give shavings, whereas rasps and files seem act more like abrasives on wood. When a file starts giving me shavings instead of dust, I call it a float.

[Greg Portland]

Thanks John. My microplane rasp is aggressive in soft wood but I don't like how it feels in harder woods (I've been trying to cut some claw feet). I'm debating between a good rasp with appropriate grain versus a float. This would also be used for fine M&T adjustment. How well does a float work on round objects (do the teeth grab and push the tool one way or the other)?

[george wilson]

Floats or files can have straight or tapered edges. Common American pattern MILL files have a gentle curve to the edge near the front end of their length.Floats do have MUCH larger teeth than files,and do cut much more aggressively. They can be sharpened.

Those curved tooth Japanese files,like John was very kind to send a sample of,are extremely sharp,and I'm sure they would do as well as any float. Their edges may be beveled,but the edges can be ground square.

I've made files with a milling machine before,but tool collectors kept buying them off my bench when I was in public!!

Floats are only for flat surfaces since they are flat. I have some curved surface files I bought from Woodcraft in the 60's. They have large,float(or vixen) type teeth,but they vibrate too much when only 1 point of contact is being made with their teeth. A #49 OLD USA made Nicholson would act better on curves. If you can't get an old USA one,get an Aeriou or Ligonier(?) hand cut French rasp. They cost el mucho money,though.

[Greg Portland]

Thanks for the feedback and education everyone, that helped a lot!