How to Install Concealed Hinges: 35mm Cups, Jigs and Overlay

Most hinge problems on new cabinet doors start with one bad hole. Concealed hinge installation comes down to boring a clean 35mm cup at the right depth and distance from the door edge, then pairing the hinge with a mounting plate that matches your cabinet box and the overlay you want. Get those three numbers right and the door hangs square, closes flush and needs only a quarter turn of adjustment. Get them wrong and no amount of screw tweaking will hide the gap.

This guide covers drilling brand-new doors: choosing the hinge, marking and boring the cups, setting plates on face-frame and frameless boxes, and hanging the door. If your doors are already drilled and you only need to tune a sagging door or swap a worn hinge into existing holes, that is a different, simpler job focused on adjustment screws rather than boring.

Plan on roughly 15 to 25 minutes per door once your jig is set, and budget an extra door blank or a piece of scrap the same thickness for test holes. A single test bore will save you from ruining a finished door.

Concealed Hinge Installation Basics: Cups, Arms and Plates

A European-style concealed hinge has three parts. The cup is the round body that sits in a 35mm hole bored into the back of the door. The arm connects the cup to the cabinet. The mounting plate screws to the cabinet side or face frame and the arm clips or slides onto it. Nearly every modern concealed hinge, from budget hardware-store packs to premium soft-close lines, uses the same 35mm cup, which is why a single boring setup works for most projects.

Three measurements control everything in a concealed hinge installation:

• Cup diameter: 35mm (about 1-3/8 inches) is the standard. A few compact and mini hinges use 26mm cups, so confirm before you drill.
• Cup depth: typically 11 to 13mm (about 1/2 inch). Doors thinner than 5/8 inch may need a shallow-cup hinge.
• Boring distance: the gap between the door edge and the edge of the cup hole, usually 3 to 6mm. Most manufacturers design around a boring distance near 5mm, and changing it shifts the overlay slightly.

Read the hinge packaging or spec sheet before touching a drill. Those sheets list the recommended boring distance, plate height and resulting overlay, and they are the most reliable reference you have.

Choosing Overlay, Half Overlay or Inset

Overlay describes how much of the cabinet edge the closed door covers. Pick the style first, because it decides which hinge arm and plate you buy.

Full Overlay

The door covers the full cabinet side or most of the face frame, leaving a small reveal between neighboring doors. Full overlay hinges have a straight arm. This is the most common look in modern kitchens and frameless cabinets.

Half Overlay

Two doors share a single partition, each covering about half of it. Half overlay hinges have a slight crank, or bend, in the arm so both doors can close on the same panel without colliding.

Inset

The door sits inside the opening, flush with the face of the cabinet. Inset hinges have a deep crank and demand tight tolerances, since a 1/16-inch error shows as an uneven gap all around the door. Inset is the least forgiving choice for a first project.

Mounting plates come in different heights, often labeled 0mm, 3mm and 6mm or similar. A taller plate pushes the door outward and reduces overlay; a shorter plate increases it. Combining arm style, plate height and boring distance lets you dial in overlay within a millimeter or two.

Tools and Materials

• Concealed hinges and matching mounting plates (two per door up to about 36 inches tall, three for 40 to 60 inches, four beyond that or for heavy doors)
• 35mm Forstner bit, ideally with a depth stop collar
• A concealed hinge jig or a drill press with a fence
• Cordless drill or driver with a clutch
• Combination square, tape measure and a sharp pencil or awl
• #6 or #7 wood screws in 5/8-inch length, or the euro screws supplied with the plates
• Cabinet door mounting jig or spacer blocks to hold doors while you mark
• Safety glasses and hearing protection

A dedicated concealed hinge jig is worth buying if you are drilling more than a handful of doors. These jigs clamp to the door edge, set the boring distance automatically and guide the Forstner bit straight, which is the hardest part to do freehand with a handheld drill. Basic plastic jigs run about the price of a nice bit, while metal jigs with integrated plate-drilling guides cost more but hold their settings better.

Step-by-Step: Boring the 35mm Cup Holes

1. Lay out hinge positions. Measure 3 to 4 inches from the top and bottom edges of the door to the center of each cup. On tall doors, center additional hinges evenly between. Avoid placing a cup where it would hit a cabinet shelf or drawer rail when the door is closed.
2. Mark the hinge side. Pencil an X on the back face of the door near the hinge edge so you never bore the show face by mistake.
3. Set the boring distance. Adjust your jig or drill press fence to the manufacturer’s recommended distance, commonly 5mm from the door edge to the edge of the hole. On a drill press, measure from the fence to the outer edge of the bit.
4. Set the depth. Lock the depth stop so the cup sits fully flush, usually 12 to 13mm deep. Test on scrap: the hinge cup flange should sit flat against the door without rocking.
5. Bore slowly. Run the bit at moderate speed and let it cut. Back out once or twice to clear chips. On melamine or thermofoil doors, a sharp bit and light pressure prevent chipping around the rim.
6. Seat the hinge. Press the cup into the hole with the arm perpendicular to the door edge. Use a square against the arm to keep it straight, then mark and pre-drill the two screw holes. Many jigs include a guide for these pilot holes.
7. Drive the screws. Set your driver clutch low. Overdriven screws strip particleboard and MDF quickly, and the hinge will loosen within months.

Check your first door before production drilling. Hold it against the cabinet with plates attached and confirm the overlay matches your target. If it is off by a millimeter or two, adjust the boring distance slightly or switch plate height rather than re-drilling.

Mounting Plates on Face-Frame vs Frameless Cabinets

Frameless Cabinets

Frameless, or European-style, boxes use the cabinet side as the hinge surface. Plates mount on the inside of the side panel, typically with their front screws 37mm back from the front edge, which aligns with the 32mm hole system many frameless boxes are built around. Line the plate center up with the cup center on the door, measured from the top of the box. A plate-positioning jig or a simple story stick cut to the door height speeds this up and keeps every door in a run at the same height.

Face-Frame Cabinets

Face-frame cabinets have a solid wood frame on the front of the box, and the hinge must either reach back to the cabinet side or attach directly to the frame. You have two options:

• Face-frame hinges: These mount directly onto the back edge of the face frame. They are the easier choice for most kitchen retrofits and are rated by the overlay they produce, such as 1/2 inch or 1-1/4 inch.
• Frameless hinges with face-frame adapters: A spacer block or adapter plate brings the mounting surface flush with the inside of the frame so a standard plate can be used. This works well when the frame overhangs the box side by 1/4 inch or more.

Measure how far the face frame overhangs the box interior before buying hardware. That dimension decides whether a standard plate reaches or an adapter is needed.

Hanging and Adjusting the Door

With cups installed and plates mounted, clip or slide each hinge arm onto its plate and tighten the locking screw if your hinge uses one. A cabinet door mounting jig, a pair of spacer blocks or a helper holding the door level makes this far easier than balancing it on your knee.

Most concealed hinges offer three-way adjustment:

• Side-to-side: the screw closest to the door moves the door left or right to even out the reveal.
• Depth: the rear screw or cam pulls the door in or pushes it out from the cabinet face.
• Height: slotted plate holes or a cam on the plate raise or lower the door.

Adjust one hinge at a time in quarter turns and close the door after every change. Aim for a consistent 1/8-inch reveal between doors in a full overlay run.

Fitting Branded and Replacement Hinges

Homeowners often search for guidance on fitting Blum hinges or mounting Blum hinges specifically, and the process in this guide applies directly: the cup size, boring distance and plate logic are the same as any 35mm European hinge. The main difference between lines is how the arm attaches, either clip-on with a release lever or slide-on with a locking screw. Clip-on designs let you install hidden hinges and remove doors in seconds without tools.

Replacement hardware follows the same rule. If you need Grass replacement hinges, such as a worn Grass 830 replacement hinge on an older cabinet, match the cup diameter, arm crank and plate type rather than hunting for an identical part number. Many discontinued hinges have modern equivalents that fit the existing 35mm cup and plate screw holes; bring the old hinge to a cabinet hardware supplier and compare side by side.

Troubleshooting Common Problems

• Door won’t close flush: The cup is likely too shallow or the arm is not fully seated. Check that the cup flange sits flat and the arm clicks onto the plate.
• Doors rub each other: Overlay is too large for the partition. Switch to a taller plate or a half overlay arm.
• Uneven reveal from top to bottom: The hinges are at slightly different boring distances, or one plate sits higher. Adjust side-to-side on the top hinge and height on the plates.
• Stripped screw holes: Glue a hardwood toothpick or dowel into the hole, trim flush, let it dry and re-drill a pilot.
• Cup hole breaks through the face: The depth stop slipped. A small blowout can be filled and painted; a full breakthrough usually means a new door.
• Chipped edges on the cup rim: Dull bit or excessive speed. Replace or sharpen the Forstner bit and use a backer when boring laminated doors.

Cost Ranges and When to Hire a Pro

Standard concealed hinges generally cost a few dollars each, while soft-close hinges from premium lines typically run higher per hinge, plus the plate. A 35mm Forstner bit and a basic jig together usually cost less than a single hour of a cabinetmaker’s shop time. For a full kitchen of 20 to 30 doors, a DIY concealed hinge installation can save several hundred dollars compared with paying per door for drilling and hanging.

Consider hiring a cabinet installer or finish carpenter when you are working with expensive custom or inset doors, when face frames are out of square, or when you need to convert traditional exposed hinges to concealed hardware on doors that already have old screw holes or mortises in visible areas. Many cabinet shops will bore doors for a modest per-door fee, which is a sensible middle ground if you want to hang and adjust them yourself.