So I ran a diamond blade on the angle grinder down to the nub, and needed to pick up a new one. As usual, I found myself standing in front of the blade display and scratchin’ my head trying to choose between continuous and notched rim blades.
I’ve never really noticed any difference between these two styles in use. Is there a rule of thumb covering which one to use?
Just curious really, since I usually just pick whichever is the cheapest. 😉
(Never found the expensive ones to last longer or cut better than the cheaper ones.)
Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.
Replies
It always depends on what you are cutting, wet or dry and the hardness and abrasiveness of the material. There are lots of different diamond blades for different purposes. The way the diamond is applied is of concern. Some are electroplated, some are brazed others are welded. This attachment method will be effected by the heat that's generated when cutting.
Some diamond surfaces are soft bonded so they wear away easier on hard materials to expose a fresh cutting surface, others are hard for softer materials. Laser welded diamond has a higher melting point than brazed, this is often used on dry blades. Segments in a blade are designed to help cool the blade and transfer lubricant. Their shape may be specific to a certain material. Continuous rims are less prone to surface chipping. They are a good choice for materials like tile.
There is also a difference in the abrasiveness of the material being cut. A hard bonded blade on a less abrasive material like brick won't expose new diamond quickly and will not cut well. A soft bonded diamond on abrasive material like block will quickly wear out.
Choosing diamond blades is like choosing wood blades, they are designed for certain purposes. Some can be used wet or dry, other are wet or dry only. Sometimes cost is more a factor of lineal feet cut. An inexpensive blade that only cuts 200LF may be more expensive in the long run over a more expensive blade that can cut 400LF.
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Sounded like, but it went right over my head being light on specifics.
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Most of what I cut with the angle grinder is either brick, block or stone (sandstone, limestone or granite), cut dry. Since I've never had any noticable problem with any blade heating up so much that it's hot to touch, I guess continuous/notched was not a big issue for those applications. (For tile, i use the wet saw, continuous rim. That one I get!)
So, given the above-described uses, any difference in continuous vs. segmented?
As for the more expensive blades lasting longer, I strongly suspect that it kinda depends on what brand you buy. Last big stone project I had, I started with a $15 cheapo. When it wore out, I went to a DeWalt for about twice the price, thinking it would do better. I swear it didn't last one bit longer than the cheapo, tho'.
As far as which blades are best for what purpose, the packaging is sure no help. They all just say wet, dry or wet/dry, and that they're good for stone, brick, concrete & tile. Not too illuminating.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
Sounds like you need an all purpose dry blade, Mike. Have you tried the turbo style. They have a continuous rim with, sort of, a wave looking relief in the edge. Here is a small selection, there are a lot of other manufacturers and price ranges.
http://www.precisiondiamondinc.com/products/grinderblades.htmlBeat it to fit / Paint it to match
"Have you tried the turbo style?"
Seen 'em, but never picked one up yet. I'll give one a shot next blade change just to compare.
I had no real complaints about any I've used so far, but I just wondered if I was missing something when the segmented blades performed pretty much exactly as the continuous ones.
Oh no! Maybe all my stone projects will fall down next year 'cause I used the wrong blade. ;-)Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
I don't know how much you use yours. But for my random work I find that the elcheapo ones from Harbor freight are fine..
William the Geezer, the sequel to Billy the Kid - Shoe
I'd say my use is occassional, at most. I've never tried the HF ones, but I may pick one up if I ever have any reason to stop in the local HF.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
Mike,
Not saying it's the best or the worst, as do not have anything for good comparison -- I use DeWalt's Turbo blades.
Seem to last a long time for me. Tile, brick, block, poured concrete, occasionally cement backer board, very occasional granite -- always dry cuts.
Jim
Never underestimate the value of a sharp pencil or good light.
Edited 7/24/2009 6:23 pm ET by JTC1
I always try to dribble a little water on them to keep the dust down.
I figure it can't hurt.
But that is only if you can. Sometimes it just isn't worth it so you get some dirty boogers.
"There are three kinds of men: The one that learns by reading, the few who learn by observation and the rest of them have to pee on the electric fence for themselves."Will Rogers
Edited 7/24/2009 11:24 pm by popawheelie
Yeah, the DeWalts worked fine -- but no better than the HD cheapos, and they sure didn't last 2-3X as long as the ones that cost 1/2 to 1/3 as much.
Go figger.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
>>....no better than the HD cheapos<<<
HD or HF? -- if HF I'll have to try some out, HF store about 10 miles away, I get in the vicinity everytime I go to the good lumberyard.......
JimNever underestimate the value of a sharp pencil or good light.
HD is where I got my, er, "more affordable" blades. BillH vouched for the HF blades. I plan to pick up one or two next time I'm in the HF neighborhood, just to check 'em out.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
best place to go is a shop that sells to the marble and granite industry, such as Hard Rock(yes that is their name) they are very knowledgeable and had online and quite a few stores in various cities-except the one one they closed by me :~(.