When installing new hardware on kitchen or bathroom cabinets, like handles, knobs or pulls, you’ll need to drill holes into the cabinet doors or drawers to mount the hardware. Choosing the right size drill bit is important for getting holes that are just the right size. Using a bit that’s too small can result in hardware that is loose and shaky. While a too-large bit will leave gaps around the hardware.
So what size drill bit should you use? The short answer is that for most common cabinet hardware like knobs and pulls, a 1/8″ drill bit is recommended. But there are some caveats and details to be aware of that this article will cover. Having the right knowledge will ensure you get professional looking results.
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Recommended Cabinet Hardware Hole Sizes
Most cabinet hardware is designed to be installed with a 1/8” hole. This includes:
– Drawer pulls
– Door knobs
– Drop handles
– Bar pulls
– Cup pulls
– Bin pulls
– U-shaped pulls
– Square pulls
– Backplates
So for most hardware, a 1/8” drill bit will be the appropriate size to use. The actual screws that come with the hardware are likely to be sized for a 1/8” hole as well.
Some specialty hardware may call for different sized holes, like 3/16″, but 1/8″ is the standard you’ll want to use for most typical installations.
Using the Hardware Template
When you purchase new hardware, it will often come with a template that shows where to drill the holes. Pay close attention to the hole size specified on the template. This is the size drill bit you’ll want to use for that particular hardware.
Some templates have multi-size holes to accommodate different drill bits. For example, the template may have both 1/8” and 3/16” hole sizes marked. Simply match your drill bit size to the template.
If no template is included with the hardware, the instruction manual may indicate the recommended hole size. If not indicated, use a 1/8” bit which will work for the majority of cabinet knobs and pulls.
Allowing for Expansion Space
Even when using the specified drill bit size on the template, you may want to make the holes slightly larger. This provides a little expansion space around the hardware.
Having some play in the holes allows the hardware to be shifted slightly during installation to adjust the positioning. The screws also won’t bind up as tightly. Allowing a little expansion room makes installing the hardware easier and reduces stress on the screws.
For most hardware, drilling holes about 1/16” larger than the specified size is recommended. So if the template calls for 1/8” holes, drilling with a 3/16” bit provides that extra expansion space.
Some tips for expansion holes when drilling:
– For 1/8” holes, go up 1/16” larger with a 3/16” drill bit
– For 3/16” holes, go up 1/16” larger with a 1/4″ bit
– For existing holes, use the next size up drill bit to expand them
– Don’t expand too much or the hardware will be loose
– A little play in the holes is ideal for stress-free installation
Adjusting for Thicker Materials
The thickness of the material you are drilling into also impacts what drill bit size to use. Thicker materials like hardwoods may require slight increases in hole sizes.
If mounting hardware on 1/2” to 3/4” thick hardwood doors or drawers, expanding regular drill bit sizes is smart. This prevents binding of the screws against the thicker material.
Consider the following expanded drill bit sizing for thicker stock:
– For 1/8″ holes, step up to a 5/32” drill bit instead of 3/16”
– For 3/16” holes, step up to a 3/8” drill bit instead of 1/4”
– For existing holes, use the next 2 sizes up to expand for thickness
– Apply this principle to other hole sizes when drilling thicker materials
The increments for drill bit sizing are smaller for larger bits. So when drilling thicker materials, be sure to go up 2 sizes rather than just one size as you would for thinner materials. This ensures plenty of room for the screws.
Drilling Pilot Holes First
For any material thicker than about 1/2″, it’s advisable to drill pilot holes before using the full-sized drill bit. Pilot holes prevent damage to the surrounding material as you drill.
To drill a pilot hole:
– Use a bit that’s about half the size of your full drill bit. For example, use a 1/16” pilot hole for a 1/8” final hole.
– Drill shallow pilot holes at each screw location through the template.
– Then switch to the full-sized drill bit and drill through using the pilot holes as a guide.
– Take care not to drill the pilot holes too deep, as they may show around the hardware. About 1/4” deep is sufficient.
Pilot holes prevent tear out, cracking and splintering as you drill the larger holes. The final holes end up much cleaner cut. Piloting is highly recommended for nice cabinets where you don’t want to take risks damaging the material.
Hole Drilling Techniques
Use the following techniques when drilling holes for hardware to get professional results:
– Tape the template in place so it doesn’t shift while drilling.
– Use a punch or awl to mark the centers of each hole through the template.
– Clamp a block of scrap wood beneath the workpiece to prevent splintering as the drill breaks through.
– Let the drill do the work smoothly without forcing it. Apply only light pressure.
– Back the drill out periodically to clear chips and prevent binding.
– Drill straight up and down without angling the drill, which can enlarge holes on one side.
– When drilling through doors, avoid tear-out by drilling from both sides halfway through the thickness.
– Deburr holes smoothly with sandpaper so screws seat properly.
Take it slow when drilling and take care not to damage surrounding material. Rushing can lead to problems needing difficult repairs.
Drilling into Different Materials
The material of the cabinets you are drilling into impacts the drill bit sizes to use:
Solid Wood:
Use standard drill bit sizes recommended for particular hardware. Expansion holes are very helpful. Pilot holes are a must for thick solid wood.
Plywood:
No need to increase hole size. Plywood is very uniform in thickness so hole sizing is straightforward. Always pilot holes first.
MDF:
No need for expanded holes in this manmade material. Hole sizing is consistent. But MDF is brittle and prone to splintering, so pilot holes are critical.
Laminates:
For plastic laminates, avoid tear-out around holes by using a stepped approach. Drill shallow with a smaller bit first, then drill through with larger bit. Piloting helps too.
Any solid wood requires extra care in drilling to prevent splintering. MDF and laminates are prone to chipping on the edges of the holes. So drill carefully and use pilots when possible based on the material.
Installing Cabinet Hardware on Drawers
Most of the above information pertains to installing hardware on cabinet doors. Drilling into drawers has some additional considerations:
Drawer fronts are thinner than doors so typically no need to increase hole sizes. But take the drawer box sides into account at the rear mounting screws. You may want to expand the back holes slightly with a thicker drawer box.
Use shorter screws on drawers. Standard hardware screws penetrate too deeply on thin drawer fronts. Opt for 1/2″ screws or measure and choose an appropriate shorter length.
Getting screws aligned between the drawer front and drawer box can be tricky. Consider using threaded inserts in the drawer box sides to make installation easier.
Tape down the template well on drawers when drilling to prevent it from moving. Misaligned holes are much harder to repair on drawers.
Other than these factors, follow the same recommendations outlined above for drilling drawer fronts. Good piloting and drilling technique prevents unsightly splintering.
Conclusion
While most cabinet hardware is designed for installation with 1/8” holes, always reference the specific template or documentation that comes with your hardware. Drilling expansion holes about 1/16” larger is also smart for ease of installation and play in the hardware. Take material thickness into account, especially with thicker solid wood. Pilot holes are highly recommended whenever possible. And be sure to use proper drilling techniques to get clean and splinter-free results. Follow these guidelines and tips when drilling for hardware and you can achieve professional looking results. For most common hardware pulls and knobs installed with the proper technique, a 1/8” drill bit will be the recommended size to use.