subject line says it all... any good rule of thumb and advice ?
I want to make sure I am buying the right blades for the bandsaw I am
about to order.
It will be cutting aluminum plate = 1.5 " thick and tubing and
extrusions (~ 0.25" wall)

bruno

I cut Aluminum with at 3000 SF/M with a 1" bi metal blade on a Delta 14"
2 hp band saw, which is a set up for ripping wood.

How I get away with it, is I push hard for 2 seconds, wait 10 seconds,
push hard for 2 seconds, etc.

That way the Aluminum never gets too hot.

--
Accidental creation should not be taught as a fact.
Intelligent creation should not be banned from teachings as
unconstitutional.

You didn't ask, but Machinery Handbook, 25th edition (page 1061) gives 500
sfm for cutting aluminum using coolant.
If cutting dry, reduce by about 30 percent.

Then on page 1057, there is a tooth selection wheel chart. Their example of
a 4 inch pipe with a 3 inch inside diameter
indicates a 4/6 variable pitch blade for the job. It seems your 0.25 wall
thickness tubing would need a somewhat finer
pitch.

Hope this helps!
Ace


"bschwand" wrote in message
oups.com...
subject line says it all... any good rule of thumb and advice ?
I want to make sure I am buying the right blades for the bandsaw I am
about to order.
It will be cutting aluminum plate = 1.5 " thick and tubing and
extrusions (~ 0.25" wall)

bruno

bschwand wrote:

subject line says it all... any good rule of thumb and advice ?
I want to make sure I am buying the right blades for the bandsaw I am
about to order.
It will be cutting aluminum plate = 1.5 " thick and tubing and
extrusions (~ 0.25" wall)

bruno

Not enough info Bruno, the subject line tells nothing of the saw you
are intending to buy.

Horizontal, vertical, hydraulics, power feed, size?

My personal pick for that stuff is a 4 or so pitch blade at about
3000-5000 feet per minute on a big vertical metal saw that looks like
what a basic wood bandsaw wants to be when it grows up. Works for me on
thick and thin stock, but you want to feed into the blade gently with
the stuff that's thinner than the gap between the teeth. It wont strip
off the teeth, but it'll get real noisy and a bit messy of a cut if you
push it in too fast. (that's my work saw) I have a wood bandsaw that was
given to me for home use, It will be used at the same sppeds as it would
be used for wood, once it is set up. The rolls of Starrett blade stock I
have at work are labeled as being for wood and non ferrous metals.

I doubt a Harbour freight $99 horizontal unit will be up to that. The
rule of thumb is supposedly you want to keep two or three teeth on the
stock at any time, and this seems good advice for a saw not equipped
with a reliable hydraulic feed limiter and coolant.

What kind of saw you lookin' at?

Cheers
Trevor Jones

The rule is 3 teeth in the cut, so for 1/4" wall you'd need at least 12 tpi, can
probably get away with 10.

For 1½" plate, however, you'd want 2 tpi, a real difference.

Normal speed for a bandsaw blade on aluminum is 800 sfpm. Feed rate is whatever
your saw can handle, depends on the saw.

GWE

Yabut the tube has two 1/4" walls being cut at the same time so...6 tpi!!!


"Grant Erwin" wrote in message
...
The rule is 3 teeth in the cut, so for 1/4" wall you'd need at least 12
tpi, can probably get away with 10.

For 1½" plate, however, you'd want 2 tpi, a real difference.

Normal speed for a bandsaw blade on aluminum is 800 sfpm. Feed rate is
whatever your saw can handle, depends on the saw.

GWE

"Tom Gardner" wrote in message
. net...
Yabut the tube has two 1/4" walls being cut at the same time so...6 tpi!!!

Nah.... three teeth across any given cross-section! Otherwise, you get
grab'n'chatter.

In real life, coarser (sharp) teeth and light cutting pressure works really
nicely for 6061.

I cut through a total cross-section of a few hundred square inches of 6061 a
month making moulds for fireworks components. Dry cutting at 800fpm with a
fresh 10tpi blade works for everything down to about 1/8" walls, so long as
I watch the down-pressure on the thinner material. As long as at least two
teeth are fully supported in each cut area, chatter and surface finish
aren't too bad.

LLoyd

Tom Gardner wrote:

Yabut the tube has two 1/4" walls being cut at the same time so...6 tpi!!!

Yabut the walls have space between them, which allows the swarf to clear
and presents 2 edges to the blade (i.e., the blade enters stock twice).
So 12 tpi is right. Bob

"Bob Engelhardt" wrote in message
...
Tom Gardner wrote:

Yabut the tube has two 1/4" walls being cut at the same time so...6
tpi!!!

Yabut the walls have space between them, which allows the swarf to clear
and presents 2 edges to the blade (i.e., the blade enters stock twice). So
12 tpi is right. Bob

So, really it depends on the diameter of the tube so as the teeth are
entering each wall with the right timing...but then the distance between the
cuts is constantly changing...Now I'm confusing myself...

"Tom Gardner" wrote in message
. net...

So, really it depends on the diameter of the tube so as the teeth are
entering each wall with the right timing...but then the distance between
the cuts is constantly changing...Now I'm confusing myself...

No it just means there should be three teeth (or more) across _any_
cross-section being cut. If you were cutting a webbed extrusion with six
1/4" walls, it would be still 12tpi. The 1/4" wall is the factor.

LLoyd