Which Bandsaw Blade should I buy to cut aluminium plate?

I've finally acquired a little Record 3 wheel bandsaw, 'found' under a tarp at the bottom of the garden at Dad's place. Been there a few years. Just powered it up and it will eat 10mm ally plate without trouble. The blade spec is 56.5 inch blades 1/4 or 3/8 wide.

Since I want to make straight cuts, I'm assuming 3/8 wide is best, but what about TPI? The commonly available blades are 14TPI for metal cutting, but I've found a supplier that can do 24TPI (which is what I use in my handsaw for Ally).

Anything else I need to watch out for when using this Bandsaw type? It's a Record BK3, but it does look like a cheap import.

Steve

Edited By Steve Withnell on 13/08/2017 11:26:17

That's a re-badged Burgess BK3 bandsaw. New blades are available here

I have the older single speed model which is still going strong after 45 years. I make up my own blades with a scarfed silver soldered joint from continuous reels.

The number of teeth needed depends on the thickness of the material. Ideally you should always have at least two teeth in contact with the material being cut. I have a reel of 32 tpi blade for thin sheet.

Russell

One thing to watch for if cutting aluminium freehand with a wood bandsaw is the heat of the aluminium ,it gets bloody hot in short time.

Subject to the two or three teeth in cut minimum coarser is better. More room in the gullet between teeth to hold the chips helping things to run smoothly and cut well. With too fine a blade tendency is to try and force the cut jamming chips into the gullet which isn't good for the blade. Machine tends to stall too.  Good point from Mark about things getting hot.  Coarser effectively runs cooler so goes further before you have too top and wait.

Bigger teeth have slightly more set in absolute terms which helps free cutting and promotes blade life. Assuming you don't break anything loss of tooth set due to wear or forcing on curves defines how long the blade lasts. When the set goes there is no clearance for the main body of the blade in the cut so it continually jams. If buying ready made blades you want all the life you can get.

If you take it steady, use the right speed and lightly lubricate when appropriate the blades will last a long time. Force or abuse it and life will be embarrassingly short. We had one of the single speed models in the trials prop workshop at one time. The EW's used to go through blades at a rate of knots. Like 3 in one day managing about a yard of cut from each! I arranged my own personal set which were still good when the saw went.

Clive

Edited By Clive Foster on 13/08/2017 12:11:34

Edited By Clive Foster on 13/08/2017 12:11:50

Thanks for that. Given that I want to cut 20mm and 30mm plate (I tried 30mm earlier and its happy with that too) then should I be thinking about 6 TPI blades? Never thought about thickness driving the TPI requirement, so every day a school day!

Steve

Doesn't that suggest a blade like the one that's already on it might be OK?

Neil

It sounds like it's OK, but what is actually best? The blade that is currently fitted is 14 TPI and coming down to 10 or 6 TPI might help prevent the blade clogging?

Steve

I find 14 TPI is a good all round compromise for most metal types. Good for thick aluminium plate and does not clog the flutes.

Mike

Only joshing

14 tpi would be a coarse blade for a hacksaw, wouldn't it.

I think my bandsaw blade is 14tpi and I cut through 3" aluminium with it without clogging, a coarser blade might require more power to make use of the bigger gullets.

Neil

The saw doesn't have loads of power to spare, so perhaps 14TPI is the best compromise.

Steve

I cannot find the link now, but I remember seeing recommendations for long-life Cobalt M42 blades from Tuffsaws.co.uk I am going to try one next on my BK3.

Andrew.

Steve, if you contact Ian at Tuffsaws I'm sure he will have recommendations. I acquired a Burgess BK3 a while back and went for a 1/4" 14tpi blade based on his advice - it has been fine in ali and (surprisingly) will also cut steel, albeit slowly. Although you can in principle go for a coarser blade in ali my gut feeling is that the machine would't have the power to cope. You also need to think about blade tension - I'm not sure that my Burgess is rigid enough to a tension a 3/8th blade adequately, and the coarser the pitch the more tension you need to resist the greater (inevitable) lateral forces.

This is the reply I had from Ian when I asked about the Burgess:

Hi Robin

Thank you for your enquiry. 

I've got this bandsaw listed as requiring 1435mm blades and because it's a 3 wheeled bandsaw the blades have to come from the Hobby/Thin Gauge range. 

For the wood cutting a 1/4" x 10tpi blade is ideal and for the metal cutting the same width but in 14tpi.
I'm not sure what the cutting speeds are on the bandsaw but for metal cutting the cutting speed needs to be around 4 times slower than for cutting wood. Usually on 2 speed bandsaws, the faster speed is for wood and the second speed is for non ferrous metal and some dense hardwoods. 
14tpi can be used on wood as well but if the cutting speed is too fast for the metal then the teeth will either strip off the blade or will just go blunt really fast. 

Here's the link to the blade on the website:

**LINK** 

The blade length and tooth pitch can be picked from the drop down menus on the page but if you have any problems or questions, please don't hesitate in contacting me.

Orders can also be placed through email or over the phone if you prefer?  

All the best 

Ian

Tuff Saws 

I've made a few mods to mine to make it more suitable for cutting metal:

1. The original blade guides were 1/4 in Tufnol rod. They soon wear, especially with fine metal dust on the blade. I have replaced them with phosphor bronze rod and they have lasted for years. Some people go the whole hog and fit ball bearing guides.

2. The frame is not very rigid and tends to flex when cutting. With the removable side being fixed by quarter turn fasteners it gives no strength. I have drilled in a few places and fitted bolts and wing nuts to clamp the whole lot together, effectively turning the narrow U channel at the back into a box section. It is now much more rigid.

3. Replaced the sliding cutting guide with a home-made one in the form of a T-square with clamp for more accurate rutting.

Russell