Grinding off bandsaw blade teeth to make a coarser blade?

[Flynth]

What do you think about grinding a bandsaw blade teeth, or have you done so, to make a coarser blade to cut bigger material?

All the stories about cutting very thick solid material with very high TPI blade notwithstanding we all know one is supposed to use proper blade TPI (Low) for cutting big solid sections.

Too high TPI, not only is expected to clog and brake teeth(I never saw that on a small saw) , but too many teeth in a cut at some point just stop cutting. Downfeed force splits amongst the teeth, and at some point there isn't enough force on each tooth. My gravity assisted saw feels like it has 15~20kg (30~40lbs) weight. While it may be fine for up to 20 teeth in a mild steel cut it surely will take forever to cut with 50 in tool steel. I remember it taking an 6tpi blade entire day to cut a 5x12 inch bar of O1 (annealed of course) (I had to remove the vice and turn it upside down half way to cut it, as the saw is too small).

Now, it appears I can't even get 6tpi blades in half inch width anymore (in EU) ... I ordered some 6tpi blades and I got 6/10 TPI with variable pitch.... When I phoned the supplier about it they told me "this is the only 6tpi bimetal blade made in this width".

Unfortunately I have no space, nor the cash to buy a big saw. Also I have to make cuts like this quite rarely.

I need to make more of those 5in by 12in bar cuts and I can't baby it entire day for one cut. So I'm thinking about grinding off every second, or two of every three teeth on that 6/10 TPI blade. Did anyone ever do anything like it?

 

[Headhunter Pipe Co]

Maybe this will help

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[benmychree]

Does Mc Master have a warehouse in Poland?

 

[Headhunter Pipe Co]

No only America
i think this company does

BANDSAW MANUFACTURING SPECIALISTS

Find the perfect bandsaw for your needs. Become a registered user and access more information and functionality.

www.bahco.com

 

[Flynth]

Does Mc Master have a warehouse in Poland?

Not with bandsaw blades in it. MC Master in Poland has a partner called BDI express, but they cater to the industry with deep pockets.

Also, most blades are sold here by custom blade makers. They keep huge rolls of carious widths and TPI and they weld it for the length of your saw. General stockists don't usually carry all the sizes, just few most popular.

The problem is that all of them use the same bimetal blades in same TPIs and for half inch widths there are no coarser tpi's than 6/10. Today I found another one that "was sure they had 6/4 TPI variable pitch" and asked me to make an order. I did. I'm expecting tomorrow the guy will be ringing me back explaining he made a mistake and he really hasn't got it...

It sounds really silly to be grinding teeth off a new blade, but what is one supposed to do?

 

[Flynth]

No only America
i think this company does

BANDSAW MANUFACTURING SPECIALISTS

Find the perfect bandsaw for your needs. Become a registered user and access more information and functionality.

www.bahco.com

Bahco are manufacturers of blade stock, not blade makers. They sell huge rolls of that blade material. Then these are bought by smaller companies that cut and weld it to size. Also Bahco has one of its factories in Belarus so I expect they probably have problems of their own because of that...

I probably rang 20 companies that specialise in bandsaw blades over last few days. The conversations usually go like this:
Option 1. Nope, we don't have it, 6/20 is the biggest TPI made in this width.
Option 2. Sure we do, go ahead and place an order.
Option 2b - on next day - Sorry, we actually don't have it, perhaps you take that 6/10 blade anyway?...
Option 3 - Why are you searching for such blade, those little saws can't handle bigger material anyway :facepalm:

 

[Headhunter Pipe Co]

Bahco are manufacturers of blade stock, not blade makers. They sell huge rolls of that blade material. Then these are bought by smaller companies that cut and weld it to size. Also Bahco has one of its factories in Belarus so I expect they probably have problems of their own because of that...

I probably rang 20 companies that specialise in bandsaw blades over last few days. The conversations usually go like this:
Option 1. Nope, we don't have it, 6/20 is the biggest TPI made in this width.
Option 2. Sure we do, go ahead and place an order.
Option 2b - on next day - Sorry, we actually don't have it, perhaps you take that 6/10 blade anyway?...
Option 3 - Why are you searching for such blade, those little saws can't handle bigger material anyway :facepalm:

I think your steps ahead anything I can suggest.
Can you take the piece to a company who can cut it ?

 

[mattthemuppet2]

Grinding off teeth won't help much unless you grind the gullet deeper and the face of the remaining tooth to match. Simply grinding off a tooth will leave a longer but shallow gullet which is more likely to fill on a long cut.

I make my own bands from larger bands with the correct depth and width. Might be something you can look into. Make a jig, buy some silver braze (40%+ Ag) and have at it. It's not hard.

 

[Flynth]

Grinding off teeth won't help much unless you grind the gullet deeper and the face of the remaining tooth to match. Simply grinding off a tooth will leave a longer but shallow gullet which is more likely to fill on a long cut.

Yes, that's one of the things I'm wondering about. If the chip is coiled into a small circle it needs as much space up as it does to the side. Making more space to the side will not help with the lack of "head room". This was another excuse one blade seller/welder said. "it's impossible to make very coarse TPI for such narrow blade, because deep gullets would compromise strength".

That's also one of the reasons why I'm dubious of variable pitch blades for thick stock in general. The 6/10 blade I got looks like it has 6tpi teeth for an inch the next inch is 10tpi with tiny little teeth and gullets. There is no way those tiny gullets can contain as much chip as the large ones. The variable pitch blade looks like 10tpi teeth would mess up big cuts and 6tpi teeth would mess up small cuts. Worst of both?

I have read lots of praise for those variable blades mainly coming from woodworkers and marketing sites. About less vibration etc. I never had any issues with vibration on solid metal cuts! Then, some websites say, it improves stock removal, it allows you to increase the feed rate a lot. I wonder if any of this is true, or is it just marketing speak?

Coming back to grinding the teeth. I think you might be right about that "gullets filling" issue. If it does I might grind them slightly deeper. At the current cost of bimetal blades (under $10) it makes sense to experiment. I might try and see how it cuts with fewer teeth without making those gullets taller as the biggest chip I got, even with 6tpi was no bigger than 1mm (40 thou) diameter.

I make my own bands from larger bands with the correct depth and width. Might be something you can look into. Make a jig, buy some silver braze (40%+ Ag) and have at it. It's not hard.

I have a tig welder. I heard those blades can be tig welded. Let's say I can join it myself, but there is the same issue trying to find the bimetal blade stock with the TPI of less than 6/10 in a fairly small amount.

 

[Jake M]

I had to remove the vice and turn it upside down half way to cut it, as the saw is too small

Well, there's the first clue as to why nobody makes a blade to do this. Of course, when I'm backed into a corner, I don't typically take good advice like that either.

I admittedly am one of those who will wait for the wrong blade to get done.... But when being cheap/lazy/practical, and when cheating just isn't working... I'm also a fan of not fighting with it too much. If you're really stuck, and the and the tool just isn't working, and clearly is not going to... If your available band saw blades cover the same price range/quality range as what's a available here, I think risking one small band saw blade might be cheap science. And if all of the tooth grinding fails totally, you still have a "test blank" to cut apart and weld together, to see if you and your welder can get it joined and straight and annealed and flattened to a satisfactory degree to consider actually making your own. That would open up a whole world of possibilities.....

You're cutting the 5 inch dimension, right? And to clarify, your 6/10 blade has the variable pitch happen frequently enough that there's always a full section of 10tpi fully engaged in the cut, right? If so, here's my thought.

I can find recommendations for harder steel that are anywhere from 6 teeth in the cut, all the way to 20 teeth in the cut. I'd take a "hope for the best, but plan for the worst" approach. I wouldn't do one in three or two in three teeth.
If you started out by going to only the 10TPI sections, and removing every other tooth, your 6/10 blade would become a 5/6 blade. You'd go from (estimating) 40 teeth in the cut, to 27 or so. Still technically too many teeth, but WAY closer... So if you dug out those teeth (and increased the gullet a bit. The 6TPI portion would have gullets really close to exactly what you need, and I'd bet with a non-power fed saw, you wouldn't need a whole lot of extra. So a very good visual reference.

So then, you could test the results with a 5/6 blade. This saw won't have the horsepower to make that cut "fast", but Is that enough to work acceptably? Maybe. Maybe you're done, and you've still got a blade that's useful (maybe even good) and could possibly go down to cutting material that is an inch/25mm or more. Or maybe it isn't enough.

If it needs "thinning" again, you could do the whole blade this time, at every other tooth, which would take the 6TPI section down to 3, and the "custom" 5TPI section would drop down to 2.5. That's going to get you down to 13ish teeth in the cut. That will get more pressure on the teeth, but that will make the blade all but unusable on stuff that's smaller than 2inch/50mm.

And, if that all completely and wholly fails, you could one more time cut out every other tooth. 1.25/1.5 TPI. That's gonna be rough on a small saw, but maybe... That would put you with 6.875 teeth in the cut. This is pretty close to the lowest side of recommendations. Which means the blade will be of no use for anything smaller than than what you're doing.