You are probably right about the metal and wood bi-metal blades, and I
should have maybe been more specific in that I was talking about the
metal sawing bi-metal blades, that I use on my band saw, I have hung a
second motor plus a jack shaft on my band saw, to bring the speed of
the blade down to be able to saw metal on my band saw.
And those metal sawing blades need more beam strength and are thicker
as well, TPI are many more than 3 or 4, however I would expect that
there are blades with that number of TPI, but the Idea that there be at
least 3 teeth in the piece that is cut, would indicate the piece to be
at more than 1" thick, seems slow going with that few cutting edges,
but there are of course exceptions.
The metal sawing blades have mostly 12 or many more TPI.
The silicon steel instead of bi-metal is I think a result of the use of
smaller wheels and less HP, bi-metal are normally made with just the
front edge of the band being harder, the rest just more flexible steel,
making thus the name BI-METAL, however that harder edge is still
vulnerable to breaking, shortening the life of the band, silicon steel
has added wear resistance build in and is less likely to break, making
it the better choice for smaller saws IMO.
And as almost always there are exceptions, like very abrasive wood
etc., just my 2cents
My setup for sawing metal on a wood bandsaw
http://homepage.mac.com/l.vanderloo/PhotoAlbum22.html
Have fun and take care
Leo Van Der Loo
robo hippy wrote:
This is a real head scratcher for me Leo, all I have ever used are bi
metal blades, and the only time I have any trouble with them is when
they are dull. I use 1/2 inch by 3 tpi on my small saw (PM industrial
1hp ), and a 1 1/4 inch blade with about 3/4 inch spaces between teeth.
Maybe they make bimetal wood and metal blades.
robo hippy
wrote:
Hi Prometheus
The problem with the bi-metal blades is to many TPI and not enough set
on them for sawing wet wood, they'll bind up and do just not work well
sawing wet wood I found, the once or twice I tried sawing wood on my
saw with the Bi-metal in place, also most BI-metal bands are wider than
thicker than the wood bands, they need more power and bigger wheel
sizes.
One other thing that does make a big difference is the saw speed in
metal sawing or wood sawing, where the wood sawing blades feed at
approx. 10X the speed of steel blades, as speed goes up so does the
friction and heat, but if you can find some bi-metal bands that do have
the 3 or 4 TPI with a good wide set than it might be more economical to
use one of those.
Have fun and take care
Leo Van Der Loo
http://homepage.mac.com/l.vanderloo/PhotoAlbum22.html
Prometheus wrote:
On 18 Jan 2007 08:23:33 -0800, "robo hippy"
wrote:
I am lucky to have a Lennox blade dealer here in town, and can get
anything that I need from him. For general bowl blank roughing a
bimetal blade works best. They last a lot longer than other blades.
While I haven't used anything else, I have several friends who have
switched to them and this is what they have told me. They are a utility
blade and good for rough work. I do have a carbide tipped blade that
costs about double what a bimetal blade does (150 inch by 1 1/4 blade
$75 to $180). I did use one for bowl blanks for a while just to see how
they did. They work fine, but don't seem to last any longer. They are
made for resawing board stock, and the dealer said that they are a must
have if you are planning to resaw your own veneers. I can get a surface
that needs almost no sanding with them, but are overkill for bowls.
robo hippy
I spent a lot of time in front of industrial bandsaws over the years,
and the conclusion I came to was the same as above- the Lennox
bi-metal blades will cut almost as long and just as well as carbide
tipped, and cost less. They're just plain tough, and if they can cut
steel 24 hours a day for a week or better, I can't imagine that there
are many woods that are going to hurt them much!