DIY Basics: Essential Guide To Drills

Handyman shows you how to choose, buy and use the best drill for your DIY needs and skills

DIY Basics: Essential Guide To Drills

A comprehensive guide to drilling, a must-read for beginner DIYers. Image: Stuart Scott

From hanging a picture to installing a deck, all drills are DIY friendly. The main choice comes down to whether to go cordless or electric. 

Electric drills are mains powered with a cord in the base and are for more heavy-duty use, with 500W a good entry level model.

Cordless drills are easy to use and often have two batteries plus a quick-charge power supply, with 10.8 to 18.0 volts ideal for DIYers. 

Jessica Deuscher from Bosch says, ‘Using lithium-ion technology, cordless drills are powerful but compact, so you can use them anywhere. With the 18 volt systems available, it’s possible to use the same battery for a range of power tools, upping the flexibility factor.’

Using Cordless Drills 

Choose the drill bit then hold the drill in one hand to grasp and twist the chuck open with the other. 

Insert the drill bit and check that it remains centred while twisting the chuck closed. 

Squeeze the trigger slightly to make sure the bit is spinning straight and the drill is charged.

Start drilling or driving slowly, using the variable speed control on the trigger for greater precision.

Step 1. Select the speed range 

Choose low speed for more power when drilling into metal and plastic or driving screws, or high speed for drilling holes into timber surfaces.

select speed range on a cordless drill
Choose low speed for more power when drilling into metal and plastic or driving screws. Image: Stuart Scott 

Step 2. Choose the clutch setting 

Select a lower setting for small screws and less dense materials, such as plasterboard. Use higher torque for decking boards and the drill setting for boring holes.

cordless drills, choose clutch setting, handyman magazine,
Select a lower setting for small screws and less dense material. Image: Stuart Scott
 

Step 3. Set forward or reverse 

Push the switch to control the direction of the chuck, forward for drilling and driving and reverse to remove a screw or extract the bit.

set forward or reverse on a cordless drill, handyman magazine,
Push the switch to control the direction of the chuck. Image: Stuart Scott 

Extend your run time 

‘The best way to extend the run time from your lithium-ion powered cordless tools is to let the tool do the work,’ says Wayne Beckwith, national training manager for Ryobi. ‘Applying excessive pressure overworks the motor and drains the battery much faster than if you let it spin at a much lighter loading.’ 

Wayne recommends checking that all accessories are in good condition and you use the right one for the job. ‘Don’t use the tool for applications it wasn’t designed for, and if your drill has a gearbox, set low gear for securing screws and high gear for most drilling.’

Types of batteries 

LITHIUM-ION Also called Li-ion these batteries cost more but only lose up to 5% of charge a month if not being used, so they’re ready to go on weekends. They provide constant full power right to the end of a charge. The battery is best put on the charger when it’s used 65% of its power.

NICKEL-CADMIUM Known as Ni-Cd these batteries lose about 20% power a month when not in use and take a couple of hours to charge. Their output dwindles as they run out of power but use them up fully before charging as they can be prone to memory effect, reducing their ability to reach full charge.

Prolong battery life 

Li-ion batteries are lighter than nickel-cadmium, have greater longevity and run for longer without losing power but they can be damaged by overheating and excessive discharge.

To maximise the life of the battery, never run the drill until the battery is flat but instead top it up after heavy use.

Avoid working in extremes of temperature and take breaks or swap the batteries over to avoid overheating if using them a lot.

Store the battery and charger in a cool, dry place and remove the battery from the tool if it’s to be stored for a long time.

Cordless screwdrivers 

Using a cordless screwdriver takes the effort out of securing screws by hand and the reverse function is for removing screws.

Ideal for working in small spaces, they’re ergonomically designed and lightweight for doing small jobs like assembling a shelf, attaching a cabinet handle or fixing a chair.

They have the least amount of power in the drill family, ranging from 2.4 to 12.0 volts but some models can drive more than 100 screws on one charge.

cordless screwdriver, handyman magazine,
A cordless screwdriver is the best tool for small jobs like tightening loose screws. Image: Stuart 

Using Electric Drills 

Open the jaws slightly larger than the selected bit using the chuck key. 

Insert the bit into the chuck just short of the bit flutes. Use the chuck key to rotate the chuck sleeve and tighten the jaws around the bit.

Switch on the power supply then squeeze the trigger switch to check the bit is spinning straight.

TIP Use the key in all three holes to ensure a firm, even pressure is exerted on the bit. 

Step 1. Select the speed range 

Choose low speed for more power when drilling into metal and plastic or driving screws, or high speed for drilling holes into timber surfaces.

ozito electric drill, select speed range, handyman magazine,
Choose low speed for more power when drilling into metal and plastic or driving screws. Image: Stuart Scott 
 

Step 2. Set forward or reverse 

Select a lower setting for small screws and less dense materials, such as plasterboard. Use higher torque for decking boards and the drill setting for boring holes.

ozito drill, set forward or reverse, handyman magazine,
Select a lower setting for small screws and less dense materials, such as plasterboard. Image: Stuart Scott 
 

Step 3. Select hammer or drill 

Push the switch to control the direction of the chuck, forward for drilling and driving and reverse to remove a screw or extract the bit.

handyman , ozito drill select hammer or drill function, handyman magazine
Push the switch to control the direction of the chuck, forward for drilling and driving and reverse to remove a screw. Image: Stuart Scott

Securing screws in timber 

To prevent timber from splitting when a screw is secured, first drill a pilot hole, especially if the joint is close to an edge.

CHOOSE A SCREW long enough to hold the workpieces securely.

INSERT THE BIT that matches the diameter of the screw body or the core without the thread.

HOLD THE DRILL at right angles to the timber so the hole is straight.

POSITION THE BIT on the timber, turn on the drill and apply slight pressure to push in the bit.

SECURE THE SCREW by changing the drill bit over to a square drive or Phillips head driver bit. 

TIP For holes more than 40mm, push in the bit a third of the way and bring it out slowly to remove the waste, pushing it in again to finish the hole. 

Screw chart 

To work out what size holes to make in softwood, divide the screw gauge by four for the pilot hole and as a rough guide halve the gauge for the clearance hole.

screwchart, handyman magazine,

Making holes for screws 

The trick to using screws is to first make a hole slightly smaller than the screw so it grabs the timber. 

PILOT HOLE makes room for the screw to reduce the risk of splitting, leaving enough timber for the thread to grab. 

CLEARANCE HOLE is made when joining timber tightly like for a butt joint, and is the same diameter as the unthreaded shank of the screw.

COUNTERSUNK HOLE is the same diameter as the screw head so it sits flush with the surface.

COMBINATION BITS make all the holes in one action but choose the size to match the screw.

SCREWS with a long thread and parallel sides need a pilot hole but tapered screws with an unthreaded shank need pilot and clearance holes.

TIP Use the screw head to check the width of a countersunk hole. 

countersunk hole diagram, handyman magazine,
The trick to using screws is to first make a hole slightly smaller than the screw so it grabs the timber

Drilling chipboard

When drilling sheets of chipboard or plywood the bit tends to cause breakout as it goes through the underside. To avoid this, position an offcut under the workpiece before drilling to support the bit as it exits.

drilling chipboard, handyman magazine,
When drilling sheets of chipboard or plywood the bit tends to cause breakout as it goes through the underside

How to choose drill bits 

Plasterboard 

Both plasterboard and the timber studs behind it are relatively easy materials to drill into, requiring only a basic 10.8 to 14.4 volt drill.

THE BEST BIT to use is a twist bit, which has a conical point and a spiral shaft to remove waste. Use a diameter to match the screw gauge if securing to the studs, or an appropriate diameter for the fastener if using a hollow wall anchor such as a toggle bolt.

DRILL THE HOLE using the faster gear, if available, and select the drill setting on the torque clutch.

twist bit, handyman magazine,
The best bit to use is a twist bit, which has a conical point and a spiral shaft to remove waste. Image: Thinkstock 

Tiles 

The bathroom and laundry often need a towel rail, mirror or soap holder attached to a tiled wall. 

THE BEST BIT for the job is a carbide-tipped glass and tile bit, as normal twist bits won’t penetrate the glaze on ceramic tiles.

DRILL THE HOLE using masking tape to mark the location and prevent the bit from sliding off the mark. Switch off the hammer function and use the auxiliary handle to hold the drill with both hands, slowing down as the bit exits the back of the tile. 

carbide-tipped glass and tile bit, handyman magazine
 The best bit for the job is a carbide-tipped glass and tile bit. Image: Thinkstock 
 

Glass 

A mirror is just glass with a reflective backing, so the same method is used for drilling holes in both.

THE BEST BIT is a diamond core bit, as glass and tile bits have a tendency to grab and may leave conspicuous chips.

DRILL THE HOLE by positioning the glass flat on a piece of plywood. To stop the bit wandering, tape cardboard over the hole position and begin drilling very slowly. Remove the cardboard to finish drilling at medium speed, applying very light pressure to avoid cracking the glass.
 

diamond core bit, handyman magazine,
The best bit is a diamond core bit, as glass and tile bits have a tendency to grab and may leave conspicuous chips. Image: Thinkstock 
 

Masonry 

Drilling into concrete and brick, called masonry, requires a hammer action to break the aggregate or brick, and drilling action to remove the waste.

THE BEST BIT to use is a multi-construction or masonry bit. Both feature a tungsten-carbide cutting point.

DRILL THE HOLE by selecting the hammer function and holding both handles. Use short bursts at low speed to start then drill at high speed, applying plenty of force and moving the bit in and out as you go. 

Metal 

The key to drilling into metal is to use low revs and cool the bit with oil.

THE BEST BIT is a HSS (high speed steel) twist bit for aluminium and steel, or a cobalt bit for stainless steel. 

DRILL THE HOLE  by using a centre punch to make a dimple in the surface, then apply a bead of putty around it and fill with oil to prevent overheating. If the hole diameter is bigger than 6mm then drill pilot holes, starting with a 2mm hole and working your way up in bit sizes.

metal drill bit, handyman magazine,
 The best bit is a HSS (high speed steel) twist bit for aluminium and steel. Image: Thinkstock 

Decking 

Whether you’re using screws, nails or a hidden fastening system to secure hardwood decking boards, making pilot holes is essential. 

THE BEST BIT for the job is a 2.5mm diameter twist bit for 10g decking screws.

DRILL THE HOLES with an electric drill because of the volume of work, using a cordless drill or impact driver to secure the screws. For nails, make holes one-third less than the diameter of the nail.

TIP Pilot holes aren’t required for treated pine decking.

decking bit, handyman magazine,
 The best bit for the job is a 2.5mm diameter twist bit for 10g decking screws
 

Specialised bits 

spade bits, handyman magazine,
SPADE BITS are traditionally large and flat with a centring point and used for drilling wide holes in timber

auger bit, handyman magazine,

AUGER BITS have a single spur, radial cutting edge and spiral flute for making extra-deep holes and mortises

plug cutter bit,

PLUG CUTTER BIT makes timber plugs that can then be used to conceal fasteners such as screw heads

dowelling bit, handyman magazine,

DOWELLlING BIT has a point at the tip to prevent it moving off the mark, aligning dowel holes precisely

forstner bit, handyman magazine,

FORSTNER BIT makes shallow, flat-bottomed holes and has a centre spur for positioning accurately

 

holesaws, handyman magazine.
HOLESAWS have a 6mm centring bit and hardened steel teeth to cut larger holes through timber and plastic

This article originally appeared in the April 2013 issue of Australian Handyman magazine 

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Essential guide to drills

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