pneum nibbler vs. shear?

i have to cut up some 20 ga sheet,4x8 ... and want
to get an air tool to bite it up , rather than saw it or grind it(a mess) what are some opinions
on nibbler vs. hand held shear? most of my cuts
will be straight or only a few deg's of curve.

how about blade life? on the two...which is gen more
useful??

i'll get both and let the tools do the talkin' .

Nibblers are VERY messy. They leave behind a sea of really sharp little half moons, which stick to your shoe soles, and get tracked everywhere. Unless you really need tight curves, I would go with a shear instead.

I have a couple of old garage sale air shears, never really got em to work right. My electric bosch shear, on the other hand, works great.
For gentle curves and straights, a two blade shear should work. It will push one side up, and the other down, and on thicker metal that can be a lot of work. A three blade will waste more metal, but leaves a cleaner edge.

Cheap shears never seem to work very well, and good shears arent cheap. Like I said, I like Bosch, but Kett also has a good rep.

i'm going to gamble on an ingersoll from
(b)lowes and see what happens. i can always return it. ..

then i'll see what's on ebay...

I recently had to cut some openings in my gas furnace to install a new humidifier and air filter. I thought about using the Bosch electric nibbler, but I knew from past experience that it would throw those little sharp chips all over, and probably even get some in the A/C evaporator and condensate pan. That would be tough to clean out. Plus, it is hard to do a straight cut with a nibbler when you are working at an uncomfortable angle.

So, I got out the Kett electric shear that I had bought years ago at a pawn shop, but never used. This is the kind that has a pair of stationary blades and a moving blade in the center, on the bottom. I drilled 1/2" starter holes at two opposite corners of the big rectangular opening. The shear worked wonderfully well. It was easy to follow the straight pencil lines, even reaching around the water heater. Each side of the opening made a single long helical chip about 1/8" wide. I had to do a little hand work at the corners to finish the cuts. There was no distortion to the furnace or to the big piece I cut out. Now, when I can't cut a sheet with my 24" Di-Acro shear, I get out the Kett.

Larry

bought the chingersoll rand p.shear from blowes
last night . it boasted "cuts 20 ga steel" on
the package . well, it struggled and sputtered,
and wouldn't hold the layout lines. i had to force
it to get it to cut at all. what i got was a ragged
edged, chewed up workpiece, that'll have to be cleaned
up w/ my angle grinder.(i recall saying i DID NOT
want to grind these parts?)
i guess i'll rough out the parts with this p.o.s.
shear , bite the bullet + bandsaw the edges w/ a
18 tpi blade (which will certainly be stripped of most teeth after this job)
then angle grind , belt sand to finish.

the shear actually works great...on .008 aluminum
flashing , 24 ga barn tin.... but wtf? why'd they
say 20 ga...(maybe if i triple annealed it ,
cut it at -20F it would cut the 20 ga steel?)

i'll trash it , take it back. the thing was $90.
i'll buy a porter cable next week when i'm in
atlanta($125("cuts to 18 ga") and see what it'll do.

Get a BOSCH 16ga elec. shear and you will not be disappointed.

[ 02-11-2007, 10:42 PM: Message edited by: JL Sargent ]

I like Draco shears...they're not cheap, but I've had my one lightweight shear for almost 20 years and it's survived some serious abuse...heavier model cuts thru cold rolled .0625 copper like butter. They have a nice rake attachment too fwiw for long cuts

Electric, cordless or pneumatic...both of mine are corded electric

http://www.dracotools.com/

I've found those half-moon style nibblers to be useless. I use an IR air saw like this for most of my sheet metal cutting. Works great!

I LOVE my Kett double cut shears.

I abuse the crap out of mine and they take it.

http://www.kett-tool.com/webpages/tools/double%20cut%20shears/double%20cut%20shears.htm

I used Bosh or Makita 2 blade electric for flat work .Nothing worked faster or stayed sharp longer. For ductwork on the job I used a Kett or Milwaukee 3 blade electric.Scribe,punch hole with hammer and scratch awl to provide starting point, and cut.Had to stop before pittsburg and cut that the width of the center blade with hacksaw.The center blade would snap off if pushed through the pittsburg on 26 and 24 ga.Blades wore quickly on 3 blade style and could not be sharpened.

I LOVE my Kett double cut shears.

Click to expand...

! Their catalog shows a 5 amp model, rated up to 14 gauge, and over 2 inches per second.

I don't need one, but now I want one. Gotta be something around here that needs to be in more pieces.

I bought that Kett 14 gauge model last year and like it a lot better than any shears or nibblers as there is no distortion of the metal, all the distortion is in the waste strip and is pretty easy to cut to a line.

If you want to see abuse of a kett shear.. look no further.



you can follow my project where I turn a large sausage fryer into a hedgehog shredder.

http://www.hobartwelders.com/mboard/showthread.php?t=3038&highlight=acres+leaves