John R. Cowan

Remember the last time you had your tires changed? The technician walked over to the wheel of your car. In his hand he held a gun like tool with a long air hose attached. He then squatted down. You heard a whirring sound as the lug nuts were removed. That gun like tool is an impact wrench.

The hammer in a hammer drill is more of a vibrator than a hammer. An impact wrench has a real hammer in it. For an excellent understanding and inside view of both a hammer drill and an impact wrench please see the illustrations, theory of operation, and inside views at www.right-drill.com

The force is hundreds to thousands of pounds depending on the manufacturer and model. It is like having a small drill with a jack hammer in it.

No because the hammer travel is limited inside of the impact wrench. It is only allowed to travel a fraction of an inch.

Yes, about 3X faster.

Yes. By not applying a lot of pressure, you can start a hole clean without the use of the hammer. also, you can lighten up at the finish of the hole. The hammer will stop and the rotor will still turn. The result is a clean hole through and through.

Cement, Concrete, stucco, brick, stone, wood, metal etc.

Any drill bit that will fit into a ½ inch drill chuck. Many larger bits have shanks that are cut down to fit into a ½ inch chuck. Cowan chuck accepts SDS drill bits too.

In between the strokes of the impact wrench, the drill bit is cooling. With the hammer drill, the bit constantly turns. The operator applies a constant force. In between vibrations, friction continues. The bit is continually heating up. Sometimes they get so hot they discolor. With the impact wrench friction is much less. The hammer pulverizes the surface under the drill. The bit only has to remove it. Result is a much cooler, longer lasting bit.

The electric drill gets hot! Sometimes you have to wear gloves. That is no fun on a hot summer’s day. The pneumatic impact wrench NEVER gets hot.

The air expelled from the pneumatic impact wrench can be used to keep the debris away from the drill hole.

The impact wrench is much lighter. Many are less than 6 pounds. Electric drills get very heavy as the power requirements increase.

Sometimes they do. The vibration of the hammer drill sometimes causes the drill bits to loosen up when drilling.
Does the drill bits in the Cowan Chuck come loose when drilling?

No. With the Cowan Chuck, you don’t even need to use the key. Hand tighten the drill into the chuck. When you start drilling, the hammer action auto tightens the chuck on the drill bit. When you stop drilling, you will find that the drill is so tight in the chuck, that you can hardly loosen it with the key. To loosen the drill bit is easy…Drill in reverse! Automatically, the bit loosens in the chuck. No more drill bits coming loose as with the hammer drill.

No. With the Cowan Chuck, you don’t even need to use the key. Hand tighten the drill into the chuck. When you start drilling, the hammer action auto tightens the chuck on the drill bit. When you stop drilling, you will find that the drill is so tight in the chuck, that you can hardly loosen it with the key. To loosen the drill bit is easy…Drill in reverse! Automatically, the bit loosens in the chuck. No more drill bits coming loose as with the hammer drill.

No. With the Cowan Chuck, you don’t even need to use the key. Hand tighten the drill into the chuck. When you start drilling, the hammer action auto tightens the chuck on the drill bit. When you stop drilling, you will find that the drill is so tight in the chuck, that you can hardly loosen it with the key. To loosen the drill bit is easy…Drill in reverse! Automatically, the bit loosens in the chuck. No more drill bits coming loose as with the hammer drill.

The pneumatic drill runs at a much slower RPM. It has no hammer. The impact wrench starts fast to give a clean hole start. It slows down to the optimum speed for drilling when the hammer starts.

You can buy a ½ inch impact wrench for as little as $20 and a compressor for less than $160. Our Cowan Chuck sells for $20. That’s a total investment of $200. An SDS drill will cost a lot more than that. Many people already own a compressor. Then the cost is only $40.

If you had to make a ¾ inch hole in a concrete wall, would you rather lean against a 5 pound impact wrench drill or try to steady a 40 pound SDS hammer drill?

When you drill a hole with a pneumatic impact wrench, you can switch to a blow gun and blow the debris out of the hole.

Cowan Chuck with an impact wrench is a Do-it-yourselfer and contractor's "must have" tool.

Yes, our Cowan Chuck has demonstrated superb performance even when used in seawater! Go to page:

Two hours later, I had only 5 holes completed. That meant, that it would take all day to drill the 17 holes!! By now the sun was up. The temperature was rising fast. The perspiration was running off of my forehead. The drill was so hot that it felt and smelled as if it was about to burn up. There had to be a better way. I took a break.

As I mulled over the problem it dawned on me that what I needed was a better hammer drill. It came to me that an impact wrench might work much better. The problem was that there is a square end on an impact wrench and no way to attach a chuck for drilling.

I came up with a makeshift drill chuck attachment. The next day I tried my new drill chuck with my impact wrench. I was delightfully surprised at how much faster and cooler I could drill the rest of the holes. Two times faster! ...And that was how the Cowan Chuck enriched my day.