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Positive vs negative blade rake

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Forum topic by MrRon posted 07-26-2019 09:18 PM 849 views 0 times favorited 8 replies Add to Favorites Watch
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MrRon

5994 posts in 4254 days


07-26-2019 09:18 PM

You use a positive rake saw blade on a table saw and a negative rake blade on a miter saw, but what blade do you use on a compound sliding miter saw; POS or NEG?


8 replies so far

View Fred Hargis's profile

Fred Hargis

6837 posts in 3504 days


#1 posted 07-26-2019 09:26 PM

Mine has an aggressive positive hook blade on it at the moment, but it’s only for home improvement duty. If I used one in the shop and wanted smooth miters I’d use a negative hook…or at least a less steep positive hook.

-- Our village hasn't lost it's idiot, he was elected to congress.

View WhyMe's profile

WhyMe

1357 posts in 2571 days


#2 posted 07-26-2019 09:46 PM

I have never used a negative rake tooth blade on a mitersaw. The blades I use are from 7deg to 12deg positive rake.

View Eric's profile

Eric

216 posts in 1248 days


#3 posted 07-28-2019 07:20 PM

I only use a negative hook ATB blade in compound mitre and sliding compound mitre saws. Allows me to cut non-ferrous metals along with wood.

-- Eric

View Markmh1's profile

Markmh1

115 posts in 1454 days


#4 posted 08-01-2019 01:41 PM

You’ll need more horsepower for negative rake, which is why miter saw blades are usually positive.

The negative rake is easier on the carbide, it will last longer.

Mark

View Ocelot's profile

Ocelot

2883 posts in 3649 days


#5 posted 08-01-2019 07:34 PM

The negative hook will reduce the tendency for sliding miter saws and radial arm saws to self-feed.

That’s why I put one on my RAS. I don’t have a sliding miter and I understand that you feed from out to in on those so I can’t say why it matters if you self-feed a little.

-Paul

-- I intended to be a woodworker, but turned into a tool and lumber collector.

View Robert's profile

Robert

4448 posts in 2491 days


#6 posted 08-01-2019 07:42 PM

SMS blades specs are 5 – 15° hook angles. (Theoretically a 5° hook angle would be safer than a 15°)

Negative rake is definitely mandatory a RAS, IMO.

-- Everything is a prototype thats why its one of a kind!!

View runswithscissors's profile

runswithscissors

3128 posts in 3035 days


#7 posted 08-02-2019 01:07 AM

Sliding miter saws feed from out to in (a push stroke) and don’t need negative rake. RASs use a pull stroke, so a positive rake blade will want to climb the board, which can be disconcerting and even dangerous. Of course, you might have other reasons to use a negative rake on a sliding miter saw, but it has nothing to do with the same issues on a RAS.

Theoretically, it should be possible to get zero chip out with a negative rake of a RAS, but not if the trailing edge (on the rising rear of the blade) contacts the wood.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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MrRon

5994 posts in 4254 days


#8 posted 08-02-2019 08:31 PM

Thanks for clearing up my confusion. SCMS-pos; RAS-neg

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