Cracks on the blade ?

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Forum topic by 716 posted 02-16-2016 04:15 AM 1043 views 0 times favorited 13 replies Add to Favorites Watch
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502 posts in 912 days

02-16-2016 04:15 AM

I was quite happy with the no name 40 teeth general purpose blade that came with my Table saw from Grizzly. Today I noticed numerous radial cracks coming from the center to the teeth. The very center of the blade that was covered by a flange is not affected. Should I be concerned or this is just coating ? The blade did see some heavy stress in particular ripping 8/4 hard maple but not for long.

Here you see cracks going through the whole blade from the center to the teeth.

-- It's nice!

13 replies so far

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2280 posts in 895 days

#1 posted 02-16-2016 04:38 AM

Toss it, blades are to cheap to take a chance!

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5112 posts in 1717 days

#2 posted 02-16-2016 05:00 AM

That kind of looks like cosmoline from shipping. The radial lines would be generated from the speed of the blade. See if they’ll clean off with some degreaser before throwing the blade out. It would make sense that they’re wouldn’t be any within the perimeter of the flange or washer as anything inside that area would be contained. If it doesn’t wipe off, it’s almost certainly a clear coat of some sort applied by the manufacturer of the blade.

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David Taylor

326 posts in 1083 days

#3 posted 02-16-2016 05:13 AM

Be sure that it’s some kind of coating before you use the blade. If the metal is truly cracked, that can be super dangerous. I do agree that it looks like some kind of coating that’s cracked, but I wouldn’t want to hear of any kind of accident. Your safety is worth much more than any tool.

-- Learn Relentlessly

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502 posts in 912 days

#4 posted 02-16-2016 05:14 AM

I actually did just that but with inconclusive results. Some crack disappeared when i rubbed then with my finger but some did not. When I scratch the remaining ones with a fingernail I definitely hear clicking sound I will try finding some magnifying glass but i doubt that will be of much help though. Maybe give a call Grizzly in the morning.

-- It's nice!

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979 posts in 1449 days

#5 posted 02-16-2016 05:35 AM

If some of the ‘crack’ wiped off, then use it. Listen to it sing when not under load and you’ll hear a burr if its cracking. I would guess its cosmoline since my G0715P was covered with it. I didn’t even consider using the factory blade and I ordered a Freud LU83 10” 50T with the saw.

(Whispers: upgrade the fence to an Incra LS-III)


-- Madmark -

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4725 posts in 2347 days

#6 posted 02-16-2016 01:07 PM

I certainly wouldn’t pay to have that sharpened. When it gets dull toss it.

-- Bondo Gaposis

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303 posts in 1814 days

#7 posted 02-16-2016 03:15 PM

Can you hang it from a piece of wire and tap it with something to hear if it will ring like a bell?
A clunking sound would indicate that it is cracked.

-- "I cut it twice and it's still too short"

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2010 posts in 1218 days

#8 posted 02-16-2016 03:16 PM

Stick your finger into the arbor hole (loosely) so that the blade is suspended horizontally. Now ring the blade like a bell. Chances are that the blade will not resonate if it is cracked.

Alternatively you can place a strong magnet on one side of the blade directly over a suspected crack.On the other side, sprinkle some iron filings (make some by filing a large nail or bolt). If the filings ‘find’ the crack line, it is confirmed.

Beyond that, I’d never run a suspected cracked blade, way too dangerous.

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4764 posts in 3239 days

#9 posted 02-16-2016 05:28 PM

If indeed the blade is cracked, return it to Grizzly. This is a hazard that can cause injury and Grizzly needs to make good.

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783 posts in 1215 days

#10 posted 02-16-2016 06:40 PM

If indeed the blade is cracked, return it to Grizzly. This is a hazard that can cause injury and Grizzly needs to make good.

- MrRon

which it looks like on the blade “never used if damaged.”
cant hurt to call grizzly and also send them pictures. they might replace it for free and also want to know about the problem.

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5112 posts in 1717 days

#11 posted 02-16-2016 08:23 PM

Another option would be to take it by a wood worker’s supply store that carries enough blades they’d have someone with a little expertise on the subject, let them take a look. There’s bound to be a few in the Sacramento area.

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586 posts in 1395 days

#12 posted 02-17-2016 06:15 AM

Another way to diagnose a crack, is the flex test: Shine a bright light on it (or take it outside on a sunny day), and apply pressure on the side opposite the suspected crack. If the crack opens up, it’s toast. This can be done by laying it on a small block of wood on a table, centering the crack over said block, and pressing down near the edges. Do this first with a blade you know is good, so you will learn how much flex resistance you should encounter. A cracked blade will throw less resistance to flex.

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502 posts in 912 days

#13 posted 02-18-2016 03:33 AM

I procured my trusty loupe today and inspected the blade closer. The blade is definitely cracked, no doubt about that. Surprisingly the long streaks from the center to the teeth is red herring but those closer to the center are real cracks, There are many of them most are under an inch long but the longest one goes around maybe 100 to 120 degrees around the center hole, it is very wavy like The walls of the crevices chipped out at places. It is not through but definitely it is not coating, too deep. Too bad I cannot photograph them.
So the blade does not go onto the saw anymore.

-- It's nice!

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