differences b/w impact wrenches, drivers, hammer drills, etc.
Can someone explain the differences between an impact wrench and an impact driver? What about hammer drills and rotary hammer drills? Is one type of drill meant for one purpose only, or can one drill do more than one function? If I wanted to drill into concrete what would I use? Or, if I wanted extreme torque on my drilling of screws, what would I use?
A real "impact driver" is this thing that looks like a screwdriver with a monster handle. You use it by putting it against the fastener you're trying to get out and whacking it with a hammer. It is capable of removing screws that won't come out any other way. What most people call an "impact driver" is really an "impact wrench." These are just automatic versions of the impact driver. Some run on air, some on electricity. Naturally, the ones that run on air work better. (The ones used at races are specially made to cope with 2500psi nitrogen.) A rotary hammer, like a Bosch or a Hilti, is made specifically to hammerdrill. There is an impact generator at the back of the tool, the armature in the motor is made to slide back and forth, and when you pull the trigger the bit both turns and hammers. These drills can't have the hammering action turned off. A hammer drill can have the hammering deactivated, but the hammering isn't as hard as it is on a rotary hammer. Rotary hammers are only for hammer-drilling. Hammer drills are good for all uses drills can be put to. My drill is a Porter-Cable 14.4v hammer drill. Great drill, but I can't recall ever drilling with the hammer on. Drilling into concrete calls for a rotary hammer--rent one if you must. Extreme torque on screws? If they're at least 1/2" screws, an impact wrench would be good; if you're driving drywall screws, set the clutch on your drill up all the way and go for it. -- --jmowreader
I have a rotary hammer which has a couple of very handy features, in that the hammer can be turned off which is nice when completing a hole and you want to go through the last portion with out causing spalling or chipping. The second feature is that the rotation can be turned off so that it can be used like a small jack hammer, another very handy feature when separating stone or concrete after drilling a series of holes, or cleaning up the edges of a large opening. Several years ago I bought a chuck which attaches to my 1/2 inch impact wrenches, this have proven invaluable when enlarging holes in heavy steel especial in the 1/2 inch and over sizes. Where a heavy duty 1/2 inch drive drill would want to catch and twist, the impact will stop and hammer through that portion of the enlargement. This is admittedly a little rough of the drill flukes, but it sure beats getting twisted around by and industrial drill motor. This is especially nice when drilling large holes in aluminum which can be a real hassle with a regular drill. Dale
Where did you find this attachment? Sound really handy. I have both an air powered and an electric powered impact wrench. They have similar torque specifications...but the air powered has MUCH more "impact" than the electric. In fact, with little load, the electric almost feels like a drill! I use the air powered almost exclusively in automotive type applications. When relying on the inertia of a part to remove a fastener (e.g a nut holding a pully on a pump) the air powered unit works great...the electric is nearly useless. The electric powered I use for construction type work. It is great for driving large lag bolts for example! Joel