what TPI for metal cutting bandsaw?

[BrokenBiker]

so, my father being as hectic as he is, blew his wood working bandsaw up the other day...rather than wait for me to have a look at it, he bought a new one...now ive had a look and all it needed was a thermal fuse, and now it works again so he has given it to me.

i can get m42 bi-metal blades the right length, but what TPI is going to be best for cutting mild, stianless and aluminium sheet, box and pipe?

probably maximum 5mm thick steel, 3mm stainless and maybe 6mm ally

would you go for a 14tpi constand or a 10-14 variable pitch blade?

 

[hotponyshoes]

I have a selection of blades for mine, the 10-14 is bar far the most used so that's what I'd go for if I was only getting one.
It's a good choice for general use in hobby type materials sizes.
I'd start with one of those then get specific blades if you have specific jobs to do.

 

[Pete.]

You might find that it runs faster than ideal for metal cutting. Do you have the facility to slow it down?

 

[fizzy]

You might find that it runs faster than ideal for metal cutting. Do you have the facility to slow it down?

Indeed so - if not an even finer toothed blade may be needed.

 

[BrokenBiker]

I have a selection of blades for mine, the 10-14 is bar far the most used so that's what I'd go for if I was only getting one.
It's a good choice for general use in hobby type materials sizes.
I'd start with one of those then get specific blades if you have specific jobs to do.

will get the 10-14 to start then, cheers

 

[Pete.]

Indeed so - if not an even finer toothed blade may be needed.

Even with a finer tooth blade the surface speed will be too high.

 

[BrokenBiker]

You might find that it runs faster than ideal for metal cutting. Do you have the facility to slow it down?

its quite a slow saw, will see if i can find the specs for it but i was surprised how slow it was cutting wood

 

[Seadog]

The surface speed has no relevance to the tooth count.

 

[GRW]

You might find that it runs faster than ideal for metal cutting. Do you have the facility to slow it down?

I thought wood saws ran way too fast for metal duty also.
My Sealey 6x4 I've run on the middle pulley setting after having it on slowest since I got it - & even that seems quite fast! (Pretty sure it's a 10-14 blade I have fitted too).

 

[BrokenBiker]

cant find the specs for it, not entirely sure what brand it is...either way, if it needs slowing down i will figure out a way to slow it down, either a cheap VFD or ill make a pulley to reduce the speed...but its a free saw so will order a blade anyway.

ive wanted one for aluminium since i got the tig, cutting steel would be nice but will see how it runs when its set up. ive got grinders, recip saws and a 14" chop saw to cut steel so not like it will be my only option.

 

[Erie Fred]

3 teeth in the cut is the rule of thumb for teeth count.

 

[BrokenBiker]

3 teeth in the cut is the rule of thumb for teeth count.

so why do variable pitch blades exist?

 

[Erie Fred]

so why do variable pitch blades exist?

Because 3 is the minimum.
And on some saws, it's to help eliminate chatter.

 

[Munkul]

so why do variable pitch blades exist?

Helps with chatter
3 teeth in the cut is the rule, but most bigger bandsaws with hydraulic downfeed can get away with just about anything. I use 4-6tpi on my saw for everything from 2mm wall hollow section up to large rounds.
We used to even cut bundles of stainless unistrut on it!

 

[minimutly]

I put a reduction drive on my bandsaw, and a vfd. it is one of the best tools I have. The vary-tooth design works well, but if cutting thin stainless you have to be careful with light feed pressure. A vfd on its own wouldn't have worked, and a 2 pulley reduction wouldn't have worked, the bigger the throat (and wheels) of course the faster the blade runs.