[arob]

hi guys,
I need to roll bimetal bandsaw blade to verious diameters , the smallest being 30mm diameter and the largest being 500mm diameter. the blade section is 1.6mm thick x 65mm wide. i assume the main body of the blade is spring steel approximately 42 to 44 r.c.
got the guy around the corner to try (rollers 100mm dia and adjusted up tight)and we could only achive a semi circle 300mm diameter, any ideas
regards,
arob.
.

[HuFlungDung]

You're not trying to make hole saws are you? You cannot make them, you must buy them!

I imagine that rolling them cold in small diameters could easily crack the back due to the amount of overbend that you must induce in order to create a permanent small radius.

I think the teeth are high speed steel welded to the back strip. So you could heat the blade up to a dull red without spoiling the temper of the teeth. You'd need to roll it fast, but you won't need to overbend it because it will be pliable. Take care not to flatten the set out of the teeth.

But you'd have to reheat, quench in oil and temper the back with typical heat treating techniques if you want to restore the springiness of the steel, after you butt weld the ends. This might help prevent the saw from going egg shaped if it is being abused in the cut.

[arob]

Hi huflungdung,
i need to make hole saws that are not available off the shelf (diameter & length).If i can roll the blade somehow without having to go through a heat treamemt process it would make the whole process easier. Plus i'm not sure if after heat treatment the holesaw will hold its concentricity. I thought about making a designated set of rollers similar to slip rolers but in a vertical plane (as the width of the blade is approximately 65mm). I thought that rolling in this manner would enable me to bring in more rollers if necessary around the diameter of the main roller but i'm not sure of the finer details of setting up the rollers and i don't want to go to a lot of work if the end result is not achievable.

Regards,
Arob