Torque vs size and weight would be my top reasons.

 

If my 1/2" pneu drill has a large d/b in the chuck, and it snags on the work piece, if I don't release the

trigger in time, it will flat spin the drill body, me included, right on around...like a do-si-do !

Uncle Bob

 

Plus they have no torque. I have one and I hate it. All it does is burn up bits and worry the metal. I gave up on it and use it as a right angle cut off tool, cause it will wind up to the full speed of a cut-off tool. Worthless as a drill.

 

Sounds like you got a cheap or defective one.

 

Torque vs size and weight would be my top reasons.

So are they for drilling relatively small holes, gazillions of them, like rivets on an aircraft? Soft metal?

I tried one once with something like a 7/16" bit in mild steel. RPMs so freakin' high it just spun the bit so fast I quit for fear of dulling it. Maybe the hole I was attempting was too large?

I see a 1/2" air drill at Freight by the Bay that is 700 rpm. That seems a lot more logical than the 3/8 versions at 1700 rpms.

Lump

 

I have a few HF ones. All of course are shit but they are much shorter and and fit into some tight spots. I only use them when I can't possible wedge a full size electric into the spot. As mentioned way too fast and no torque. So when I do use them I generally get the job done with a few hundred more cuss words and a handful of dull/broken bits. Oh and since they are HF drills...oil everywhere out the *** end of it. They look cool though. In a pinch you could probably rob someone with it. That would be about the only time the tool paid for itself.

 

I think the biggest attraction for them is this. If you are already using air tools such as doing bodywork. Size as mentioned. And you already got the hoses run. A electrical cord would just get in the way wand get tangled up. Have to put it away as soon as you finish, as opposed to Just get the air job.

As for the speed thing. Soft metals like aluminum and sheet metal do like higher speeds just got to use cutting oil to cool the bit. I used to work in a machine shop and the speed setting was higher using a small bit on soft stuff. Cuts right through like butter. At least where I was that is what they had us doing on the drill presses.

 

I have a smaller HF one that is crap, wouldn't buy it again, couldn't drill a hole to save it's life. I have used others that have been awesome, TONS of torque. You can use them in wet/hazardous locations without worry. Stall them out without damage. Make sure you are supplying them with the proper amount of air as they use a lot, you aren't going to run one effectively with a pancake compressor.

Not to knock HF, I have gotten plenty of decent tools from them, but some things you get what you pay for. Never used the larger one from HF so maybe that is a good one... Only one way to find out.

 

I'm thinking about that 1/2", 700 RPM HF drill, if I can find a good, or even not so good, reason to own one. I'm totally happy with their Earthquake impact gun. I'm also thinking of buying their Earthquake 3/8 air ratchet. I have a Klutch that's great until you reach torque. Then it takes your hand for a hard ride. The HF ratchet has that "non-knuckle bust" technology.

Lump

 

One advantage to an air drill is that it won't get hot so quickly when you're drilling a gazillionty dozen hundred holes. The high RPM's "sort of" make up for the admittedly low torque. Sheet metal, plastics, wood and holes less than 3/8" and they're fine. And the batteries don't run down and the air hose is probably within arm's reach anyway. But it's a matter of choice. Buy one if you want; most tools end up being useful far beyond the job you originally bought them for.
-Mike-