Thread: How many TPI is enough?

green or dry?

Kiln dried

1.2 tpi, seems vvvvvery coarse, especially in timber 10-80mm thick.
3 or 6 tpi will do the job well.

as for overheating the blade, well blades get hot and there are a lot of reasons,

1. hard timber / timber density
2. feed rate
3. thickness of timber
4. speed of blade
5. sharpness of the blade.

There are probably more these are just a few factors, .

Jeff

Thanks for replying Jeff. Blade overheating would be due to those factors too, not only on TPI i imagine. Its too late to change the order but it really worries me that this is the recommendation by Henry Bros. Will report back here once I get it...

1.2TPI would be fair recommendation if you're milling logs.

But if you're mainly ripping dry, pre-milled lumber and/or using it for non-straight cuts (eg. shaping aprons, legs, etc. as many home woodies are wont to do) then in my opinion you're better off changing your blade to cater for the "2 to 4 teeth in the cut" rule.

It's a good rule of thumb.

Why? This gives reasonable sawdust scavenging and gives a decent finish to the cut surfaces, while allowing for good cutting speed.

Too many teeth in the cut can cause the blade to clog, increasing overheating & maybe causing burn marks unless you slow the rate of feed.

Too few and the cut quality can decrease dramatically; not a bad thing if you're just after rough-sawn but not really desirable if you're into cabinet-making.

I recently bought a 1 tpi blade for my bandsaw after reading the spiel about how great it was.
I am sorry I bought it, the finish it left was a bit like a chainsaw. I tried breaking down an old hard burl that I had stored in the shed for years, I thought I was going to wreck my bandsaw by the time I was half way through, it was trying to self-feed and pulling the burl in too quick, ended up bending one of the teeth.
I took it off and bought a 2 tpi blade, I am much happier with this one, though it doesnt give me the same quality finish as the old 3 tpi blade gave me.
I was told by the supplier that I couldnt get a 3 tpi bimetal blade for cutting wood, if I wanted 3 tpi I would have to buy a metal cutting blade.

I use 3tpi with one a negative rake as per 's suggestion a long time ago.

Peter.

Thanks for your responses, at least others may avoid falling into the same trap. The general consensus appears to be anything 2 or above is best for this kind of work...

Skew, I think you are spot on about it being good for milling logs as opposed to dried/pre-milled stuff. It looks like it, after I got home today and opened the package. I'm actually a bit scared to use it haha, it just looks overkill for what I intend to use it for...Have a look...

Ironwood, do you remember who or where it was recommended to go with 1 TPI? The surface quality is another issue with this pitch. I'm planning on using the bandsaw to rip the boards instead of using a tablesaw.

I agree that blade is scary , for what you need I think it is defiantly overkill.

A finer tooth blade would be far better, i think the finished cut will be very coarse.

Jeff

I know of a few people who've settled on one "general purpose all-round blade" that lives permanently on their machine, but to my mind that's a bit like settling on just one grit of paper for a belt-sander.

I guess 'tis alright to have just the one blade if most of your cuts are the same "type"... but a bandsaw is a very versatile machine and you're wasting a lot of it's capability if you go the one blade path!

I have a whole slew of blades in different tpi - hi tpi for flatwork thru to low tpi for plain ol' ripping - in varying blade thicknesses so I can cut different radii. At last count I had something like 14 different sets.

I also like to keep two or three of the ones I use most, so I can send a group of blades off for sharpening, continue on with my work and still have a spare in case I break/blunt the one currently in use.

I recently got a digital caliper and measured the thickness of the 3/4" wide blade mentioned at the beginning of this post, which I found was ~0.035" thick. My major gripe is when I ordered it from Henry Bros, I specifically asked if they sell it in 0.025" *NOT 0.035"* and was told 'yes'. Long story cut short, I spoke to Henry Bros after making my discovery and the answer I got back was I should forget everything I've read that says I shouldn't use 3/4" wide 0.035" thick blades on a 14" bandsaw and that it will work fine.

For those of you who haven't read Mark Dugniske's book, he claims that 3/4" blades shouldn't be used because they tend to be > 0.025" thick and they can't be properly tensioned on 14" bandsaws and will result in the blade breaking prematurely and potentially damaging the bandsaw frame because it places too much stress on it.

Originally Posted by Cin

I recently got a digital caliper and measured the thickness of the 3/4" wide blade mentioned at the beginning of this post, which I found was ~0.035" thick. My major gripe is when I ordered it from Henry Bros, I specifically asked if they sell it in 0.025" *NOT 0.035"* and was told 'yes'. Long story cut short, I spoke to Henry Bros after making my discovery and the answer I got back was I should forget everything I've read that says I shouldn't use 3/4" wide 0.035" thick blades on a 14" bandsaw and that it will work fine.

For those of you who haven't read Mark Dugniske's book, he claims that 3/4" blades shouldn't be used because they tend to be > 0.025" thick and they can't be properly tensioned on 14" bandsaws and will result in the blade breaking prematurely and potentially damaging the bandsaw frame because it places too much stress on it.

I'm not an expert, as my 14" is my 1st bandsaw. But I've noticed that my new 3tpi 3/4" definitely doesn't tension or cut as easily as my 1/2" 6tpi does. I prefer the 1/2" for ease personally.

Just what I've found with my limited experience.

Before I go ahead and order blades for my new 19" bandsaw, maybe I should ask some advice as well?

It was supplied with a 3TPI blade which I believed was for resawing.
I found,as well, that it is very difficult to tension that size blade and, it tends to drift a lot.
I was also told that 2TPI is better because of the larger gullets..
After reading these posts, I am totally confused.
I want to resaw some large slabs of white apple, black wattle, milky pine and mango.
However, I also wish to do some finer cuts like bandsawn boxes.
Suggestions please.

Cheers
Wolffie

Originally Posted by Cin

I read somewhere that there should always be at least 3 teeth in the piece of timber you are cutting with a bandsaw. While ordering a blade recently, I was told that 1.2 TPI is best because the blade won't overheat. My question is, what would you use for ripping timber anywhere between 10-60mm thick? Most of the timber I will be ripping is Tas Oak, Myrtle, Blackwood

Hi. I have a large old bandsaw (36") and the blade is 1"/25mm with 20mm between teeth. That is 20/25 = 4/5" between teeth, so 5/4 = 1.25 tpi.

I've used it for roughly resawing timber so far - another thing I need to get back to - but the cut surface is not horribly rough ... at least relative to the size of the wood. There is video of it working online, but I thought some pics might help.

edit: grrr ... clicked too soon.
This is cutting 12"-14" ... don't know about using it for 10mm-60mm. It'll cut *fast* but probably 3-6 tpi might be of more general use to you.

Cheers,
Paul