Perry Holbrook
06-01-2010, 9:24 AM
I know there are a lot of BS blade questions here, but I just ran into something that I have not seen discussed.
Background. I do a lot of band sawing and have recently upgraded from an 18" Jet saw to a Grizzly G698 17" saw. I use bi metal blades. For a good bit of my work I use a 3/16 wide blade. I discovered that instead of using the standard kerf .025" blades that if I use an M42 blade with a .035" kerf that I can cut smaller radius turns. This is preferred over a thinner width blades because I cut 2" maple with the table tilted at 25 deg making small radius turns. Making those cuts you tend to pull against the blade and the smaller/thinner blades deflect too much.
I ordered a standard kerf and an M42 from my local saw shop when I bought the saw. The standard blade has had no problems. However the M42 has now broken twice. Both times it lasted less than 2 hrs. I took it to the shop this morning and discussed this with the owner. He said that the blade may be too thick for a 17" wheel. He said that as the weld is flexed around the wheel, the thicker blade doesn't bend as well as the standard, creating stress that breaks the blade. He said he has seen it several times on bench top saws and thought it could be true for me too.
I few things to consider. The M42 always ran well on the 18" saw. Tension should not be an issue, the blade is tensioned correctly and as a matter of fact, the thicker kerf blade should withstand more tension due to it's increaded cross surface area. The 17" saw has almost a 50% higher blade speed, 3000 vs 4500 so the blade does flex a lot more often.
The saw shop is going to re-weld again, this time with a little more heat and more annealing. Due to my schedule it will be a couple of weeks before I can try it out again.
So, anybody have any thoughts or past experiences.
Thanks, Perry
Background. I do a lot of band sawing and have recently upgraded from an 18" Jet saw to a Grizzly G698 17" saw. I use bi metal blades. For a good bit of my work I use a 3/16 wide blade. I discovered that instead of using the standard kerf .025" blades that if I use an M42 blade with a .035" kerf that I can cut smaller radius turns. This is preferred over a thinner width blades because I cut 2" maple with the table tilted at 25 deg making small radius turns. Making those cuts you tend to pull against the blade and the smaller/thinner blades deflect too much.
I ordered a standard kerf and an M42 from my local saw shop when I bought the saw. The standard blade has had no problems. However the M42 has now broken twice. Both times it lasted less than 2 hrs. I took it to the shop this morning and discussed this with the owner. He said that the blade may be too thick for a 17" wheel. He said that as the weld is flexed around the wheel, the thicker blade doesn't bend as well as the standard, creating stress that breaks the blade. He said he has seen it several times on bench top saws and thought it could be true for me too.
I few things to consider. The M42 always ran well on the 18" saw. Tension should not be an issue, the blade is tensioned correctly and as a matter of fact, the thicker kerf blade should withstand more tension due to it's increaded cross surface area. The 17" saw has almost a 50% higher blade speed, 3000 vs 4500 so the blade does flex a lot more often.
The saw shop is going to re-weld again, this time with a little more heat and more annealing. Due to my schedule it will be a couple of weeks before I can try it out again.
So, anybody have any thoughts or past experiences.
Thanks, Perry