Can you imagine driving 6,000 drywall nails a day, setting each one to the right depth with a hammer? That's how many nails you'd need to attach 3,000 square feet of drywall, and that's how we used to do it.

The first time I hung drywall, I helped my grandfather hang a ceiling. We struggled to hold each panel up with one hand and nail it with the other. We had to set pairs of nails 1 1/2 inches apart, and space each pair by 12 inches. My grandfather kept barking orders. "Hit one nail, then the other. Don't tear the drywall paper. Don't set the nails too far apart," he'd say. There was no way I was going to get this right. My arms ached, and it wasn't any fun. There had to be a better way. I bought my first drywall screwgun about 20 years ago, and I've enjoyed hanging drywall ever since.

It's amazing how a power tool can change the whole prospect of a job. These days, screwguns are a must. It takes approximately 1,000 screws to attach 1,000 square feet of drywall. An average crew can hang 3,500 square feet or more a day. That's a lot of screws.

When choosing a drywall gun, I look for tools that are well balanced, light, comfortable, and fast. Many hangers love the physical aspects of lifting, cutting, and fitting, but fastening is a different story. A quality screwgun is as vital for a drywall installer as a good power saw is for a house framer. Screwing drywall is the only way to go. Here's why:

-- A screw head is smaller and easier to conceal than a nail head indented with a hammer blow.

-- Driving screws is a lot faster than driving nails. Attaching drywall generally requires fewer screws than nails.

-- A screwgun pushes drywall against the framing as it fastens the panel.

-- A screw's holding power is much greater than a nail's. A drywall screw has up to 350 percent more pull-out strength than a nail does.

-- Only screws can attach drywall to metal framing.

How a Screwgun Works

A screwgun sets screws' bugle heads just below the drywall paper surface. The tools' positive clutches engage when pressure is applied to the Phillips bit and release when the pressure releases. You can adjust the screw bit depth and how deep it sets screws. As a screwgun sets each screw to the correct depth adjustment, the screw pulls the panel tight against the framing as pressure from the nosepiece pushes against the drywall. The screw head spins against the paper as it sinks, leaving a slight dimple and a clean, smooth edge around the head. When the screw reaches its proper depth, the clutch disengages.

To use a screwgun properly, hold the tool firmly as you drive each screw. That way, your hand and forearm absorb most of the stress. Your wrist should almost align with the nosepiece, and your thumb, index, and middle fingers ride along either side of the motor housing. Pull the trigger and push the tool forward with a punching motion. That engages the clutch, starts the screw rotating, sinks it, and disengages the clutch in a fraction of a second. If you don't maintain pressure on the tool after engaging the clutch, the screw won't set properly.

Criteria

We tested nine drywall screwguns made by Bosch, DeWalt, Grabber, Hilti, Makita, Metabo, Milwaukee, and Porter-Cable. We used them to attach 1/2-inch drywall to wood and metal framing. Although the tools can be used for other things like fastening wood furring or installing additional nailers in corners, I limited the test to drywall attachment. We evaluated each screwgun after using it all day on a typical drywalling job. Some hangers run their screwguns at full speed with the trigger locked on, while others press the trigger as each screw is installed. We tested these tools using both methods.

All the tools did a fine job of setting screws in panels. They differed when reaching into corners or running along the top edge of a panel. Some were more comfortable to hold than others, especially when working near a ceiling or along the top edge of a wall panel. We evaluated each tool's comfort, noise level, switch location and ease of use, depth adjustment, bit replacement, variable-speed features, and belt-clip practicality.

Comfort. A screwgun must be easy to hold onto. We found the Makita, DeWalt and Grabber tools to be the most comfortable. The thickness and angle of their handles seemed just right. I especially liked the cushioned rubber grips.

Except for the Milwaukee and Porter-Cable tools, all the models we tested have finger grooves along their top edges. These indentations make the guns easier to hold onto without squeezing them to death. All the models are pretty lightweight, ranging from 3.3 to 4.2 pounds.

Noise. Screwguns running full blast can be very loud and irritating. I am happy to say the new screwguns we tested are all a lot quieter, and their noise levels are quite tolerable.

Switches. Screwguns commonly are used in locked-on, full-speed mode, so a lock-on switch's ease of use is an important issue. A good one lets you relax your fingers.

I like to be able to hold and lock on a screwgun with one hand. The Makita and Bosch models are the easiest to operate with one hand, but it's hard to do that with the DeWalt and Grabber gun.

Depth adjustment and bit replacement. The only thing I want to do with a screwgun is attach drywall. If the trigger switch or lead goes bad, I take the tool to the repair shop. The only mechanical thing I will do is adjust the bit depth and occasionally change the bit. The easier these things are to do, the better.

The depth adjustments on most models we tested are easy to use. Just slightly turn the end of the nosepiece and you're all set. We had to pull out the Porter-Cable and Bosch depth adjustments before we could turn and set them. The Bosch adjustment is difficult to remove. I prefer to just turn the nosepiece to make adjustments.

You must remove a screwgun's nosepiece when replacing the screw bit. The Bosch nosepiece unscrews; the other tools' nosepieces pull off. Next, you have to grip the magnetic bit holder with one hand and pull off the screw bit with the other. Metabo addressed screw-bit adjustment beautifully on its tool. Just pull up on a special spring-loaded holder to release the bit. Pull up the bit holder again to install the new bit. It works great. All the screwguns in this test come with magnetic screw bit holders that hold screws firmly on the bits.

Variable speed. If a screwgun is exclusively used for installing drywall, you might think it doesn't need a variable-speed switch. It's cheaper to manufacture a tool with a single-speed switch, but equipping a drywall screwgun with variable speeds gives it a soft-start feature that can increase the motor's life. This is especially important if a user turns a screwgun on and off as each screw is inserted, instead of locking the trigger on.

Belt clip. All the models we tested have belt clips that work just fine. Some belt clips are removable; Makita's retract. I find it easier to properly set a screw along an inside corner if I remove a gun's belt clip, so Makita's fold-back clip is a nice feature. The Milwaukee and Metabo tools won't set screws any closer than 3/4-inch from a corner with their clips in place. But remove their clips, and the tools get within 1/2-inch of a corner like the rest of the screwguns we tested.

Warranty

All screwguns in this test carry typical one-year limited warranties. The DeWalt tool also comes with a 30-day satisfaction guarantee. If you're not happy with the tool after you buy it, you can return it up to 30 days later and the dealer will refund your money. No questions asked.

Favorites

The Makita tools are our unanimous favorites. Both models tied for first place, but I liked the Makita 6824 best, while my crew chose the Makita 6825. I think the 6825--the only 6,000-rpm model on the market--is a little too fast, especially on metal framing. The DeWalt DW274 is almost as good as Makita's tools, except you can't work the DW274's lock-on switch with your operating hand. The rest of the tools finished like this: After DeWalt, we liked the Grabber 4063, Hilti SD45, then Porter-Cable's 6640, Metabo's SE5040 R&L, Milwaukee's 6755-1, and Bosch's 420 VSR.

Myron R. Ferguson is a drywall contractor in Galway N.Y. He is the author of Drywall: Professional Techniques for Walls and Ceilings, published by Taunton Press.