Circular saw, slightly oversized blade....

[UliKunkel]

Hello,

First real post here, so forgive if this topic has already come up (I did a search but didnt find anything)...

I have an 184mm circular saw (Skil) which is older (1865U1). Anyway I bought a 190mm blade for it by accident (and on sale so I can't return it). I mounted the blade and it turns fine without any issue, but I haven't had the courage to use it least it explode on me. Is there any issue with using this blade in my saw?

I don't have the manual, and on the saw there is no "maximum diameter" listed.

Thanks in advance!

 

[Diver Fred]

Provided the new blade isn't touching the blade cover at any point and also the blade has sufficient space to clear the saw dust away you ought to be OK. Just don't force the saw when cutting - particularly at maximum cutting depth.

 

[TheUnicorn]

My gut says that such a small difference would make no difference, especially as the guard still closes down without issue, my nagging concern would be that the outside is spinning just that little bit faster than it would be 3mm further in and that the machine isn't calibrated for that. I'm fairly confident that the added size and added speed of the edge would be within the tolerence of the machine though

 

[Bingy man]

Would cutting at 45 deg make any difference?

 

[Sideways]

If it spins freely, have at it.
A small percentage difference in diameter is entirely trivial. UK mains voltage varies by over 10% place to place and time to time, and so does the speed of (just about) every tool with a brush motor in the country except the few that have a tacho and constant speed under load electronics. I really don't see 3mm on the diameter as important so long as there's room for it.

 

[ChaiLatte]

I don't have the manual, and on the saw there is no "maximum diameter" listed.

The saw would likely have its rpm listed on its data plate. The blade would likely have a maximum rpm written on it.

If you think about it 190/184 is 3% extra. If a device is built in a way that it cannot cope with 3% variation without serious consequences, it is not built properly.

 

[TheUnicorn]

Would cutting at 45 deg make any difference?

cant see how it would make any difference, the blade would still be contained within the guard

 

[Fergie 307]

I would be more concerned about checking the blade width versus the thickness of the riving knife. If that is ok then go for it.

 

[Fitzroy]

Would happily use this set up. You may however find you can no longer make a zero, or very shallow, depth cut as the blade remains proud of the base in its most extended position.

 

[Jameshow]

Would happily use this set up. You may however find you can no longer make a zero, or very shallow, depth cut as the blade remains proud of the base in its most extended position.

I don't think you can make a zero cut ever!!

 

[ChaiLatte]

You may however find you can no longer make a zero, or very shallow, depth cut as the blade remains proud of the base in its most extended position.

More as an observation/tip, if a saw will not go shallow enough for a specific cut, a piece of plywood screwed to the base wll often resolve the issue. A thin piece such as 6mm would still allow use of the standard fence if required.

 

[Fitzroy]

I don't think you can make a zero cut ever!!

Cheeky! I often do a dry run of operations, running the piece through the tool, or the tool over the workpiece to ensure there are no snags. That was really what I meant by a zero depth cut. I once got halfway through a cut and the power cable was not long enough, which was problematic.

 

[TheUnicorn]

Cheeky! I often do a dry run of operations, running the piece through the tool, or the tool over the workpiece to ensure there are no snags. That was really what I meant by a zero depth cut. I once got halfway through a cut and the power cable was not long enough, which was problematic.

that's a good habit to get into, even just mentally, working through a cut, or any job in part or in full, nothing worse than constantly stop starting because you either don't have what you need, or have something in the way.

 

[UliKunkel]

The saw would likely have its rpm listed on its data plate. The blade would likely have a maximum rpm written on it.

If you think about it 190/184 is 3% extra. If a device is built in a way that it cannot cope with 3% variation without serious consequences, it is not built properly.

Thanks! The saw is 4200rpm, and the blade is 8000 rpm. I suppose that is a pass?

 

[meccarroll]

Most machinery (panel saws etc) have a max and minimum blade size meaning you can safely run any blade size withinn the max-minimum range. If the blade fits without catching then I would use it no problem, in the past I have purchased saw blades with a slightly different diameter and fit them in my hand held circular saws.

 

[Henniep]

Agree with the sentiments above. Technically, the bigger blade's "tip speed" will be factionally slower resulting a marginal loss of cutting power.

 

[TheUnicorn]

Agree with the sentiments above. Technically, the bigger blade's "tip speed" will be factionally slower resulting a marginal loss of cutting power.

why would the tip speed be slower? assuming the rpm stays constant, a larger disc would be spinning faster on the outside edge, or are you suggesting the rpms would be affected by the greater size?