which saw blade?

[pswallace]

Hi,can anyone recommend A good quality 250mm saw blade for A portable table saw? . . . .I would be cutting various types of material (mdf,ply,hardwood) I'm getting A bit confused about negative rake,pitch,kerf and so on,I would like to buy A general purpose blade that can be used for rip cuts or cross cuts.Can anyone advise ? thanks Phil.

 

[RogerP]

If we are definitely talking about a table saw and not hand-held circular saw then I would recommend the Freud LP30M TCT Saw Blade for Long/Cross Grain Cutting 250mm x 30mm x 40t

Here is one source. You don't say what the bore is. This one is 30mm but other sizes or converter rings are available.

I've been using one for ages and I'm very pleased with it. I've just ripped some 2" timber and straight after some 4mm ply sheet - both with first class results.

 

[pswallace]

Thanks for the reply Roger,yea it is A table saw,I should have said bench top ,it's A De-walt and I would have used cheap throw away blades in the past like Draper at £10 - £12 A pop but lately the work I'm being asked to do is A bit finer than usual and when i used a saw belonging to another joinery crew in A bar I was fitting out recently I couldn't believe the difference in the quality of cut. I'm going to check out that freud range you suggested but I will go for one with more teeth for A finer cut I think. Thanks Phil.

 

[RogerP]

You'll sacrifice rip cutting performance if you go for more teeth.

 

[matthewwh]

Hi Phil,

Ripping and crosscutting in one blade is a compromise and you will not get the same performance as you would with dedicated blades. Having said that, if you understand that you need to be working well within the capacity of the blade (i.e. not trying to do full depth cuts in exotics etc) there are universal rip / crosscut blades available. Scroll down to T1042 and click 'view options' to select your bore diameter. I would recommend the heaver industrial resharpenable one as the quality and stability of the cut is so much better and they usually work out cheaper in the long run, but if you prefer a throw away one, this is the nearest alternative.

Positive hook is for tools where the blade comes through the table (tablesaws / portable saws). Negative hook is for tools where the blade moves over the table (chop saws, sliding mitre saws etc). Choosing the appropriate hook angle ensures that the wood is pushed safely towards the table or fence as it is being cut.

Pitch is the number of teeth, for ripping the tooth itself is less important than the gullet between the teeth. Ripping tends to produce long ribbon like shavings (think of a plane shaving) which need plenty of space to spiral up into before the blade exits the timber and they are ejected. With crosscutting you don't need the gullet space since you are cutting across the fibres and producing dust rather than ribbons, and you get a finer finish with lots of teeth - hence you can't have a blade that is fully optimised for both operations.

Kerf is the name for the slot that the blade cuts, it is fractionally wider than the diameter of the teeth.

Hope this helps.

 

[RogerP]

........hence you can't have a blade that is fully optimised for both operations.

I do have both rip and crosscut blades, but as I have only the one table saw, continual changing blades is a pain so I tend to mainly use the Freud 40t which does give remarkably good results in either direction.

 

[pswallace]

..I'd wondered what the negative,positive hook thing was about. I do have A sliding mitre saw but it can be A heavy big thing to move about so I recently built A simple cross cut sled to fit the De-walt and I have to agree with Roger ,it can be A pain changing the blade over especially if it's only for one cut that probably wont be showing anyway hence the need for the universal blade ! I came across 250mm fine kerf blades by CMT ..1.7mm,what are the benefits of fine kerf blades?,I know they are used in cordless saws, I assume to place less strain on the motor but what are the benefits in larger more powerful saws? Phil.

 

[cutting solutions]

Wow nice values......

There really is no "compromise" blade.
If you want to rip you need a rip blade
if you want to crosscut you want a crosscut blade and
if you want fine finish you need a fine finish blade.

so 250 mm diameter=
rip 20/24 teeth
crosscut 40/48 teeth
fine finish 80 teeth.

Now if you want to give up some of the standard you can get blades in between.
so
36 teeth you could use for ripping but would have to push the timber through slower and may not get a good finish on crosscutting
60 teeth again would need to be slower for crosscutting but may not give the real fine finish you may want.

and alot of this depends on the material being cut too.......

Thinner kerf blades should really only be used where material waste may be crucial or you may be looking for a very fine finish.
I have seen 40 tooth blades with thinner kerf (on 250 diamater) but unless you are sure of the application I would not recommend them.
the thinner blade would have to work much harder to cut through heavier material and may put strains on the motor.


cant say in 26 years of selling blades I have ever seen a saw blade produce shavings....always dust.
kerf is the width of the tooth....on 250 mm usually 3.2 mm and should normally be 1.0 mm thicker than the steel body of the blade.
you may see a desription such as:
250 x 3.2/2.2 x 30 Z=24 ATB
250 mm diameter
3.2 mm width of carbide tooth
2.2 mm thickness of the plate (body of the blade)
30 mm bore size
Z=24 number of teeth
ATB tooth configuration (alternate bevel)

But unless you guys have real specialist requirements I wouldnt advise getting too deeply into all this.....it can get very confusing even for professionals selling to high level manufacturing companies.

Hope that has helped.
Doug

 

[Digit]

I have a SIP 10 inch TS and use Freud blades. Apart from DIY work I work exclusively in hardwoods and use a rip blade for ripping and a cross cut for cross cutting. The time taken to change blades is minimal, much less than the time taken to deal with chimbling if you use a rip blade for cross cutting.
Funnily enough a bought a 150 mm Freud blade yesterday for my circular saw espescially for cutting ply and man made materials, and the results are much supier to the GP blade supplied.
Horses for courses.

Roy.

 

[monkeybiter]

Another issue with using thinner T blades is the need for a thinner riving knife. Re. the cutting effort required, I seriously doubt more effort would would be required to cut a thinner slot removing less material, providing dust removal was still adequate. JMHO

 

[marcros]

Wow nice values......

There really is no "compromise" blade.
If you want to rip you need a rip blade
if you want to crosscut you want a crosscut blade and
if you want fine finish you need a fine finish blade.

so 250 mm diameter=
rip 20/24 teeth
crosscut 40/48 teeth
fine finish 80 teeth.

Now if you want to give up some of the standard you can get blades in between.
so
36 teeth you could use for ripping but would have to push the timber through slower and may not get a good finish on crosscutting
60 teeth again would need to be slower for crosscutting but may not give the real fine finish you may want.

and alot of this depends on the material being cut too.......

Thinner kerf blades should really only be used where material waste may be crucial or you may be looking for a very fine finish.
I have seen 40 tooth blades with thinner kerf (on 250 diamater) but unless you are sure of the application I would not recommend them.
the thinner blade would have to work much harder to cut through heavier material and may put strains on the motor.


cant say in 26 years of selling blades I have ever seen a saw blade produce shavings....always dust.
kerf is the width of the tooth....on 250 mm usually 3.2 mm and should normally be 1.0 mm thicker than the steel body of the blade.
you may see a desription such as:
250 x 3.2/2.2 x 30 Z=24 ATB
250 mm diameter
3.2 mm width of carbide tooth
2.2 mm thickness of the plate (body of the blade)
30 mm bore size
Z=24 number of teeth
ATB tooth configuration (alternate bevel)

But unless you guys have real specialist requirements I wouldnt advise getting too deeply into all this.....it can get very confusing even for professionals selling to high level manufacturing companies.

Hope that has helped.
Doug

Doug,

What would you recommend for cutting plywood both plane and veneer faced?

Thanks
Mark

 

[SteveB43]

"Positive hook is for tools where the blade comes through the table (tablesaws / portable saws). Negative hook is for tools where the blade moves over the table (chop saws, sliding mitre saws etc). Choosing the appropriate hook angle ensures that the wood is pushed safely towards the table or fence as it is being cut."

..from Matthew's post..

However with a portable circular saw, surely that moves over the wood being cut (imagining a cross cut), in the same way a sliding mitre saw does. Would'nt you then need a negative hook multi tooth blade and does such a thing exist??
Just trying to get the dynamics of blade action on the wood being cut clear in my head...
Cheers!

 

[cutting solutions]

Doug,

What would you recommend for cutting plywood both plane and veneer faced?

Thanks
Mark

Mark
sorry for delay getting back to you.
needed to check if the blade was available to me.

I would suggest severe alternate bevel.
most ATB blades have 10 or 15 degree angles across the top.
what you really need is something with 35 degree bevels
unfortunately unless you want 20 of them I cant supply them at economical prices.
for 250 diameter 80 teeth would be good.

I used to sell them......
Have a look at Stehle (who used to do them :wink: ) or Freud
i am sure one of them will have something close.....

 

[Hudson Carpentry]

I have a thin Kerf CMT blade and it makes an excellent finish no matter if im cross cutting or ripping (60 teeth maybe more). However, if your just taking off a very slim bit of material they deflect and your left with a beveled cut.

 

[Krysstel]

I've just (yesterday) put one of these in my Metabo TS250 (probably very similar to a DW) and the difference in cut quality from the original Metabo blade was astounding. http://www.workshopheaven.com/tools/PT250-40_250mm_40_Tooth_Woodcutting_Circular_Saw_Blade.html
WSH also have a more expensive range here http://www.workshopheaven.com/tools...iversal_Rip-Cross_Cut_Circular_Saw_Blade.html
All can, I beleive, also be ordered directly from Atkinson Walker.

Mark