What Size Hole for Cabinet Hardware? 3/16 Inch — and Four Other Specs I Check Before Buying

The short answer: 3/16 inch

For cabinet knobs and pulls, drill a 3/16" hole through the door or drawer front. That's the clearance hole for the #8-32 machine screws that ship with most cabinet hardware sold in North America. If the screw binds, step up to 13/64". If you're hanging metric hardware, M4 screws want 4.5–5 mm.

Here's the rest of it, for anyone who only reads the top of the page:

• Garage door extension springs: match by rated door weight, not by length or by what looks close. Replace in pairs.
• Rolling tool box: the number that matters is the per-drawer load rating, not the total capacity printed on the box.
• Electrician screwdriver set: "insulated" is a marketing word. IEC 60900 rated to 1,000 V is a standard. Buy the standard.
• Richelieu: if you're sourcing cabinet or door hardware in volume, use the spec sheets — they list the mounting screw and hole size per item so you're not guessing from a photo.

Why you should weigh my answer at all

I'm not a cabinetmaker and I'm not a garage door tech. I'm the office administrator for a 70-person company with a fabrication shop and eight service vans. I manage the shop and facility purchasing — roughly $140,000 a year across nine vendors. I report to operations and to finance, which means I hear about it from both sides when something arrives wrong.

When I took over purchasing in 2020, I ordered the way most people order: cheapest option with decent reviews. That lasted about eighteen months. In our 2024 vendor consolidation project, I cut nine vendors to five and moved most of the hardware onto one catalogue. Ordering time went from about six hours a month to under two. The invoices finally matched the POs, too, which finance cared about more than the savings.

Along the way I drilled a lot of bad holes and bought a few things I shouldn't have. That's the credential.

The cabinet hardware hole size, properly

The screw determines the hole. Not the knob, not the pull, not the brand. Almost every knob and pull I've ordered in the last three years ships with an 8-32 machine screw, which measures 0.164" across the threads. A 3/16" hole is 0.1875", which gives you clearance without slop. That's the whole calculation.

Where people go wrong is the mental model. The "grab whatever bit is in the drawer" approach comes from an era when most cabinet hardware attached with wood screws into a pilot hole, and hole size was forgiving because the screw cut its own threads. That's changed. Machine screws don't cut. They need a clearance hole or they bind, and if you force an 8-32 through a 5/32" hole in a lacquered maple door, you'll learn what blowout means.

Quick reference, since this is the part people screenshot:

• 3/16" — standard clearance for #8-32 hardware in wood-based doors and drawer fronts
• 5/32" — deliberate interference fit, soft material only, and you'd better be ready to ream it
• 4.5–5 mm — M4 metric hardware
• 7/64" to 3/32" — only if you're genuinely driving #8 wood screws into solid wood

Hole size isn't what ruins installs, though. Center-to-center spacing does. A pull with 128 mm spacing on a drawer front drilled for 96 mm is a problem no drill bit fixes. If you're matching existing holes, measure them. If you're starting fresh, pick the pull before you touch the door.

Here's the thing that surprised me. When I compared two failed drawer slides side by side — same brand, same catalogue, different series — I finally understood why the price gap on the shelf tells you almost nothing about the failure rate in service. The cheap series was $2.40 less per slide. The labor to swap one out was $45 and about half an hour of a fabricator's day. Fourteen swaps on the cheap series over two years, zero on the mid-tier. That's roughly $630 of labor to save $34 in parts. (Those numbers are from our own PO log for 2023–2024, not from memory.)

One more, because I got this wrong twice: 3/16" is right for a 3/4" door and also right for a 5/8" door. The screw in the bag may not be. A 1" screw covers most 3/4" doors, but on a 5/8" door with a thick pull post, that screw can bottom out and never tighten down. Check screw length against door thickness plus post depth before you start. (Note to self: I really should keep a 3/4" and a 1" screw bin at the bench.)

Garage door extension springs: weight, not length

Extension springs are rated by door weight, and the colour band on the spring is the manufacturer's shorthand for that rated load. The chart mapping colours to weights hangs in the aisle at most supply houses. If you're replacing one, you match four things: rated weight, relaxed length, wire diameter, and inside diameter. You also replace both, even if only one broke — a pair that's half new and half fatigued pulls the door crooked and wears the track.

The mistake I made in 2022 was buying on length and price. The old spring was 25" and the replacement was 25", so it should have worked. It didn't. The door wouldn't stay up and the opener was doing all the lifting. A spring that's under-rated for the door doesn't fail gracefully. If I remember correctly, that door weighed about 130 lb and the springs were rated for 110. The right pair was $30 more.

And here's the part that isn't a purchasing decision at all. Extension springs are under tension and they fail violently. They need safety cables run through them, and if you're not the person who does this for a living, you're buying a service call, not a spring. DASMA (the Door & Access Systems Manufacturers Association) publishes the residential spring-system standards installers work from — that tells you how seriously the trade treats this.

One caution on sourcing: residential sectional door springs and commercial rolling door springs are different animals with different rules. Don't cross the catalogues.

Rolling tool boxes: read the drawer rating

If you're searching for a masterloader rolling tool box, you're after what everyone in this category wants — a heavy rolling chest that survives a shop floor. The search term itself is a small trap. Names in this category get reused across resellers, and the same box turns up under two or three labels. Search the specs, not the badge.

What I check, in order:

1. Per-drawer load rating. A 50 lb drawer and a 250 lb drawer look identical in a listing photo. Our shop drawers routinely hold 100 lb of sockets and steel, so anything under 100 lb per drawer is out.
2. Slide type. Ball-bearing, full extension. Friction slides on a tool chest are a decision someone made at the factory, and it wasn't for your benefit.
3. Caster size and material. 5" polyurethane over 4" hard plastic, every time. Hard wheels flat-spot on concrete, rattle, and mark the floor.
4. Gauge. A box that flexes when you push it loaded is a box with misaligned drawers in a year.
5. Locking. One bar for all drawers or individual locks, either is fine — but if you're buying more than one, confirm they're keyed alike. Ours weren't, and now there are four keys on the shop board.

The reverse-intuition part: most of the gap between a $400 box and a $900 box is in the slides and the casters — the two things you can't see in the photo. I went back and forth between the cheap chest and the mid-tier one for a week. What decided it wasn't the box. It was the $45 in labor every time a slide gets replaced, which we'd already paid for on the shop cabinets. Same lesson, different product.

Electrician screwdriver sets: the rating is the product

"Insulated" on a product page means nothing. Every screwdriver handle is made of something that doesn't conduct much. The question is whether the tool was tested to a standard. For hand tools used near live conductors, that standard is IEC 60900 — live working hand tools rated up to 1,000 V AC and 1,500 V DC. In North America you'll also see ASTM F1505, which covers the same ground.

What that buys you: insulation bonded to the shaft rather than slipped over it, routine dielectric testing, and a marked voltage rating. What it doesn't buy you is permission to work on energized equipment. That's a separate conversation governed by NFPA 70E and your own electrical safety program. A rated screwdriver is one layer of protection, not a licence.

For a shop set, the practical contents: #1 and #2 Phillips, #1 and #2 Robertson (if you're in Canada, this isn't optional), 3/16" and 1/4" slotted, and a couple of Torx sizes. Cabinet-tip flat drivers for terminal screws are genuinely different from a standard slotted driver and worth the extra few dollars.

Everyone in my shop who's been handed an unrated set has eventually used it on something live. One of those cost us a $260 control board when the shaft insulation split. The rated set would have been $70. I bought the rated sets after that and stopped having the argument.

Where Richelieu fits, and where this advice stops

We buy most of our cabinet and door hardware through Richelieu's catalogue, largely because the item pages carry the specs I actually need — mounting screw size, hole spacing, slide load ratings, caster specs. That removes the guesswork on the hole size question, since the screw size is listed per item instead of buried in a photo. It's a distributor catalogue with a wide range and trade pricing, which suits a shop our size. It isn't our only source and shouldn't be — fasteners and abrasives still come from elsewhere because the pricing works better that way.

Now the boundaries, because a couple of these topics don't really belong in the same article.

• Hole size: 3/16" is the answer for standard 8-32 hardware in wood-based cabinet doors and drawer fronts. It is not the answer for metal cabinets, glass fronts, or doors with a factory-machined hole pattern. Drill a test piece. Always.
• Garage door springs: everything above applies to residential sectional doors with extension springs. Torsion systems, commercial overhead doors, and anything unusually wide are outside what I'd touch from a purchasing desk. Hire it out.
• Rolling tool boxes: if the box gets rolled over gravel, off a dock lip, or up a ramp daily, casters matter more than drawers and you should be looking at a cart, not a chest.
• Epoxy garage floors: if you searched for plancher epoxy garage Saint-Jean-sur-Richelieu and landed here, I can't help you. That's a coating contractor, not a hardware catalogue, and I'm not going to pretend otherwise. The only purchasing-side note I'd add is sequencing — if you're coating a garage floor and installing shelving or cabinets, decide the order first. Coating after installation means taping around every leg. Installing after coating means every dropped wrench is a repair. We put the shelving in first and had the floor done around it, which I'd do the other way next time.
• The actual work: none of this replaces the person doing it. I'm a buyer. I know what to order and what to verify. I don't know what your door weighs.

If there's a thread running through all of it, it's that the cheapest option is rarely the cheapest outcome — the $2.40 slide, the $30 spring, the unrated screwdriver set. None of them looked expensive at the time. All of them cost more than the good version. The one thing I'd change about the last five years is that I'd have started measuring and reading spec sheets about two years earlier than I did.