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Up Topic Welding Industry / General Welding Discussion / Sawing 304 or 409 .065" exhaust tubing
- - By jwright650 (*****) Date 04-02-2018 20:13 Edited 04-02-2018 20:33
Any recommendations for band saw blades that will last more than a few cuts? (93" x .032" x 3/4")
I've been burning through the saw blades at home trying to cut this 3" SS exhaust tubing(.065" wall). I slowed the saw down to 86 fpm thinking it would help, but it still ends up ripping the teeth off long sections of the blade.
I can cut it with an abrasive cutting wheel, but the saw cut is a lot nicer to fit and weld, especially when trying to cut small pie cut sections to make smooth tight radius bends from a straight section of tubing.
Parent - - By yojimbo (***) Date 04-03-2018 02:33
JR-

I don't remember ever having that trouble or going through blades that quickly.  I use a Milwaukee portaband and generally Milwaukee blades.  Don't remember tooth count off hand.  Lock them into the pipe vice/tripod and have at it.  The shop that sharpens my carbide tipped Freud blades for the DeWalt multicutter sells a waxy lubricant that seems to get a little more life to the blades before resharpening.  Might try some of that stuff.
Parent - - By 803056 (*****) Date 04-03-2018 04:01 Edited 04-03-2018 13:47
The tubing is thin wall, so you need to go with a high tooth count per inch bimetal blade.

The 0.065 inch wall tubing is ripping the teeth off the blade. You should speak with the salesman to make sure he knows what you are cutting. I would go with something like 32 or 48 teeth per inch. It will start cutting slowly because you are cutting on the round surface, but as it cuts through the tube wall, the cut will go faster. You need at least a couple of teeth engaging the tube wall to prevent the blade from dropping and tearing off the teeth.

Forgive my representation of a saw blade, but I think it conveys what I'm talking about.

If you have too many teeth trying to cut, the gullet will fill with chips and stop the cut and cause the blade to dull too quickly. The bottom line is you need more than one blade. A blade for each thickness range. Pipe and tube present a problem because the OD represents "thick" material, but once the wall is breached, it is thin. A slow start is better than ripping the teeth off with every cut.

Al
Parent - - By jwright650 (*****) Date 04-03-2018 11:10
I was using saw blade charts to decide what to purchase. The guide had me at 14-18tpi for 1/16" material and I was using bimetal blades. Maybe I need to go to a carbide tipped tooth blade? I flood it with coolant and slowed the blade down as slow as I can get it with my saw. I'll try to speak to a human salesman...LOL
I hope my saw isn't too fast for the blades, because I can't slow it down any further without replacing the pulley set. I have the belt down in the slowest set of pulleys already.
Parent - - By Lawrence (*****) Date 04-03-2018 11:51
Sub out the cuts and have the guy down the street buy the blades  :)
Parent - - By jwright650 (*****) Date 04-03-2018 12:46
L,
Excellent Idea!...however this is a turbo exhaust system that I'm putting together for my 70 Camaro at home.
Wait....I do know a guy, maybe he can quote me price per cut and we can work something out.
This is not mine, but is an example of what I'm doing...


Parent - - By 803056 (*****) Date 04-03-2018 13:51
Hello John;

With 14 TPI you would have the second condition shown in my sketch. The thin wall could have moments when there is no tooth cutting and the blade can drop so the tube is between the teeth. Riiipppp, there goes three or four more teeth.

Just my thoughts on the matter.

Looks like an interesting "weekend" project.

Al
Parent - - By jwright650 (*****) Date 04-03-2018 15:01
I should clarified that the blade is a variable pitch 14-18...but still understand what you are saying.

I need to make a better vice for the (horz band) saw. I would love to build a vice where I could place U or J mandrel bends in there and could clamp them down where I could cut anywhere along the radius of the bend. It would "cut" out a lot of pie cuts and welding. I could just buy the tubing with 180° U bends or J bends and then cut it somewhere along the radius to get the angles that I need to get this tubing through the firewall and down under the car and out the back.
Parent - By 803056 (*****) Date 04-03-2018 15:13
OK, now it sounds like several weekends of work.

Al
Up Topic Welding Industry / General Welding Discussion / Sawing 304 or 409 .065" exhaust tubing

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