How to Drive Screws Perfectly
For such a simple task, it’s surprising how many things can go wrong when you drive screws. Stripped screw heads, split board ends and broken screws are just a few common problems. We’ll show you how you can avoid all the frustration just by using the right screws and a few special tools.
Look for Torx-Head Screws
Torx-head screws have been common on automobiles for a long time, but now they’re available for general construction use too. Star-shaped Torx bits fit tightly into the star-shaped recess in the head of the screw, providing a firm grip that rarely slips out or strips the screw head. It’s easier to drive these screws because you don’t have to press down as hard to maintain good bit contact. Plus, most Torx-head screws are premium-quality fasteners available with other features like self-drilling points, self-setting heads and corrosion-resistant coatings.
Torx-head screws require star-shaped bits that are labeled with a ‘T’ followed by a number. Some screw packages include a driver bit, but if yours doesn’t, check the package to see what size is required. If there’s a downside to Torx-head screws, it’s the price. You wouldn’t want to use them to hang drywall.
Buy a Set of Countersink Bits
Drilling a pilot hole for the screw and then creating a recess, or countersink, for the screw head is standard practice on cabinets and furniture projects. The pilot hole bit creates a hole that reduces friction to make screw driving easier, and the countersink allows you to set the screw head flush with or below the surface. For straight-shank screws, the less expensive straight-bit design works fine. For tapered-shank wood screws, use a countersink fitted with a tapered-shank bit.
Countersink bits are available with or without stop collars. An adjustable stop collar lets you set the maximum depth of the countersink for more consistent results. Also, you can hide the screw by drilling a deep countersink, called a counterbore, and gluing a plug into the hole. Countersink drill bits are available in sizes to match screw sizes. If you’re an avid woodworker, it’s worth buying a full set. Otherwise, a No. 7 or No. 8 will cover the most common screw size.
Use a Magnetic Bit-Tip Holder
If you’re new to driving screws with a drill, you may not know the many benefits of using a magnetic bit holder. First, and most obvious, is that it holds any driver bit with a standard 1/4-in. hex-shape base, making it super quick and easy to change bits. But there are other advantages too. The bit holder extends the length of the bit, making it much easier to get into tight spots. The magnet in the bit holder magnetizes the tip, allowing you to hold ferrous-metal screws in place on the end of the bit for easier driving (top photo). And if you buy a bit holder with a sleeve, like the one shown here, you can use it to hold long screws upright as you drive them in (bottom photo). Look for a magnetic bit holder that’s at least 3 in. long and includes the sleeve.
Tack First, Then Drive Screws
It can be frustrating and time consuming to try to hold parts in place while you drill pilot holes and drive screws. Here’s a trick that solves the problem and speeds up assembly too. Tack the parts together first with a brad or finish nail gun. That enables you to align the parts with one hand while you tack with the other. Once everything is held in the right position, it’s simple to drill the pilot/countersink holes and drive the screws.
Get a Cordless Impact Driver
Nothing beats impact drivers for driving screws easily. Impact drivers combine hammer-like blows with rotation to apply plenty of torque to the screw head. The hammer action means you don’t have to press down hard to keep the bit in contact with the screw. This allows you to drive screws one-handed in spots that would be hard to reach otherwise. But beyond this advantage, the extra torque makes it simpler to drive any screw, especially long ones.
Trim-Head Screws Aren’t Just for Trim
Trim-head screws are slender screws with very small heads. Originally they were designed to attach wood trim to walls built with steel studs. But now you can go to the fasteners department in any home center or full-service hardware store and find trim-head screws in several colors, long lengths, corrosion-resistant finishes or stainless steel, which make them perfect replacements for nails in many situations. When sunk slightly below the surface, the heads on these screws are small enough to be covered easily with wood filler or color putty.
Here we’re using trim-head screws to connect a fence rail to a post. But you can also use them in place of galvanized casing nails to install exterior doors and windows, or to attach exterior trim. Trim-head screws have several advantages over nails. They hold better and are easier to install in tight areas. Plus, if you’re not an experienced carpenter, they allow you to install trim without worrying about denting it with an errant hammer blow. Keep a supply of trim-head screws of various lengths on hand and you’ll be surprised how often you reach for them rather than nails.
Ditch the Lag Screws
The next time you build a deck, gazebo or fence that requires lag screws, consider using a modern version instead. These new structural screws are just as strong but skinnier, and they have specially designed tips and threads to make it easier to drive them in. You don’t even have to drill pilot holes. And you can drive them with a standard drill, impact driver or strong cordless drill. They cost a little more than conventional lag screws. But if you’ve got better things to do than waste time with lag screws, they’re worth every cent.
Install Drywall with Special Tools
If you’re considering driving drywall screws with a cordless drill and a regular Phillips-bit driver, don’t. Drywall screws have to be driven to exactly the right depth. Too shallow, and you won’t be able to cover them with joint compound; too deep, and you’ll break through the paper face of the drywall, which will give you ugly drywall screw pops later. It’s nearly impossible to drive screws quickly and accurately without special tools.
Here are your choices. If you only have a few sheets of drywall to hang, you can buy a special tip for your cordless drill that limits the depth you can drive the screw. These drywall screw tips cost just a few dollars and work well if you’re careful. A better option is a driver drill that’s built to drive drywall screws. You can buy a time-saving auto-feed version (center photo) that uses special collated screws, or a dedicated drywall screw gun (left) that drives regular drywall screws. Both versions have adjustable nosepieces for precise depth control. If you only need the tool for one drywall job, consider renting one for a day or two.
Adjust the Clutch to Avoid Stripped Screw Heads
At times, drills can provide too much power, causing screw heads to snap off or strip, especially with small brass or aluminum screws. Most newer cordless drills are equipped with a clutch, which can eliminate this problem. Set the clutch by twisting the ring near the chuck to the smallest number. Try driving a screw. If the clutch releases (you’ll hear a ratcheting noise) before the screw is fully driven, move the setting to a higher number. Choose a setting that drives the screw fully before the clutch releases.
Note: Using square or star-drive screws and bits reduces the tendency for the bit to slip off the screw head.
Use a Self-Centering Bit When Mounting Hardware
When you drill pilot holes for hardware mounting screws, it’s tough to keep the hole centered. And if the hole is off-center, the screw won’t seat properly. That’s where self-centering pilot bits come in handy. Self-centering bits drill a centered pilot hole (the cone-shape guide keeps the bit centered while you drill the hole) resulting in perfectly centered screws. There are several sizes of self-centering bits available. Choose one to match the size of screw you’re using.
Line It Up and Push Hard
Driving screws with a drill can be tricky until you master the technique. The most common mistake beginners make is applying too little pressure. Coupled with bad alignment, this spells trouble. If the bit is skipping out of the screw head and you already know that the bit isn’t worn, then improving your technique will help. First, be sure the driver bit is aligned with the screw shank. If the bit’s sitting crooked in the screw, it won’t engage firmly and will slip. Then, with the bit firmly seated, start the drill slowly (assuming you have a variable-speed drill) while pushing hard against the screw. Apply extra pressure with a hand on the back of the drill body. The combination of correct alignment, pressure and slow speed will ensure that the screw goes in without bit slippage, which can damage the screw head and driver bit.
Drill Pilot Holes for Toe Screws
Driving screws at an angle (toe-screwing) is a common technique for making right-angle connections. But if you simply angle the screw in the desired direction, it will usually just slip down the board. The key to successfully driving screws at an angle is to use this two-step process to create an angled pilot hole. Choose a drill bit with a diameter equal to the screw shank, not including the threads. First, estimate the entry point based on the length of the screw. Then start the bit at a right angle to the wood at this point (top photo). As soon as the drill bit engages the wood, tilt the bit to the desired angle and finish drilling the pilot hole (bottom photo). Now drive the screw into the angled pilot hole to complete the job.
Don’t Use a Worn Bit
Using worn driver bits is a common mistake.This worn bit should have been replaced with a new one before it got this bad. If you’re using the right technique and the bit is still skipping in the screw head, it’s time to replace the bit. The trick is to have spare bits on hand so you can replace them at the first sign of wear. The next time you’re at the home center, buy a 10-pack of No. 2 Phillips bits and you’ll always have spares. Don’t forget to get a few of the other sizes and shapes too.
Note: Match the driver bit size to the size of the recess in the screw head. The three common sizes of Phillips bits, smallest to largest, are No. 1, No. 2 and No. 3. Can’t tell by looking? Pick the bit with the tightest fit.
Drill Clearance Holes
Have you ever screwed two boards together but not been able to pull the two pieces tight together? This happens when the screw threads engage in both pieces of wood while there’s still a gap between them. One solution is to clamp or nail the boards together before making the permanent screw connection. If you don’t want to mess with clamps or nailing, you can drill a clearance hole through the first board to solve the problem. The clearance hole allows the screw to spin until the boards are tight together. Choose a clearance hole bit that’s large enough to allow the screw to spin freely. Even cupped or twisted boards are easily drawn tight with this method.