How to Install Threaded Inserts in a Guitar Neck — Step by Step

Installing threaded inserts in a bolt-on guitar neck is one of the best upgrades you can make — and one of the simplest. No woodworking experience needed. No special skills. If you can drill a straight hole, you can do this in about 20 minutes.

This guide covers the full process: what you need, how to prepare, and how to install the inserts without messing anything up.

What You’ll Need

Included in a threaded insert kit:

• 4 threaded inserts (brass or steel)
• 4 matching machine screws
• Mounting tool (for driving inserts straight)

You’ll need to supply:

• A power drill or cordless drill
• The correct drill bit (6.5mm for M4 inserts, 8.5mm for M5 inserts)
• A hex wrench / Allen key (size depends on the screw head — usually 3mm)
• A screwdriver to remove the old wood screws
• Optional: a piece of masking tape for depth marking
• Optional: a drop of wood glue (for extra hold in soft woods)

Do NOT use:

• A power drill to drive in the inserts — hand tool only, you need to feel the resistance
• A power drill to tighten the final screws — snug by hand is enough

Step 1: Remove the Old Neck Screws

Unscrew the four wood screws from the back of the guitar body. Set the neck plate and screws aside — you’ll reuse the neck plate but not the old screws.

Carefully lift the neck out of the pocket.

Tip: Take a photo of the neck position in the pocket before removal. This helps if your neck has a specific alignment you want to maintain.

Step 2: Inspect the Screw Holes

Look at the four screw holes in the heel of the neck (the flat end that sits in the body pocket). You may see:

• Clean holes: Original holes that haven’t been damaged. Great — the inserts will fit perfectly.
• Slightly enlarged holes: The wood screws have worn the holes a bit. Still fine for inserts.
• Stripped / blown-out holes: Visible wood damage, possibly filled with old glue or toothpicks from a previous repair. Clean out any debris first.

If holes are badly damaged, clean them out completely. Remove any old glue, toothpick remnants, or loose wood fibers. A small flat-head screwdriver works well for this.

Step 3: Drill the Holes to the Correct Diameter

The existing screw holes from wood screws are too narrow for threaded inserts. You need to widen them.

For M4 inserts: Use a 6.5mm drill bit

For M5 inserts: Use an 8.5mm drill bit

How to drill straight:

1. Mark the correct depth on your drill bit with a piece of masking tape. The hole needs to be deep enough for the insert to sit flush — typically about 12-15mm.
2. Place the drill bit into the existing hole — the old hole acts as a natural center guide.
3. Drill slowly, keeping the drill perpendicular to the neck surface. Let the drill do the work — don’t push hard.
4. Stop at the tape mark. Remove the drill and clear the wood dust.
5. Repeat for all four holes.

Important: Drill into the neck heel (where the screws go IN), not through the body. The body holes stay as they are — the machine screws pass through the body freely and thread into the inserts in the neck.

Step 4: Install the Threaded Inserts

This is the most critical step. The insert must go in straight. A crooked insert means a crooked screw, which means the neck won’t seat properly.

Using a mounting tool (recommended):

1. Thread one insert onto the tip of the mounting tool
2. Place the insert into the drilled hole
3. Using a hex wrench, slowly turn the mounting tool clockwise
4. The insert will thread itself into the wood, pulling itself in straight
5. Keep turning until the insert sits flush with the neck surface — not below, not above
6. Unthread the mounting tool and remove it
7. Repeat for the remaining three holes

The mounting tool is designed to keep the insert perfectly aligned as it goes in. Without it, the insert can tilt, which is very hard to correct once it’s in the wood.

Without a mounting tool:

Thread a machine screw into the insert, leaving about 10mm of screw sticking out above. Use pliers or a wrench on the screw head to drive the insert in. This works but requires much more care to keep things straight.

Tip for soft woods (basswood, alder): Add a small drop of wood glue into the hole before driving the insert. This bonds the outer surface of the insert to the surrounding wood for an even tighter fit. Not necessary for maple or harder woods.

Step 5: Reattach the Neck

1. Place the neck back into the body pocket — align it using your reference photo
2. Place the neck plate on the back of the body
3. Drop the new machine screws through the body holes and the neck plate
4. Thread each screw by hand — you should feel it catch the metal threads of the insert immediately
5. Tighten all four screws evenly — go around in a star pattern (like tightening a car wheel), not one at a time
6. Tighten until snug. Do not use a power tool. Hand-tight with a hex wrench is all you need.

You should feel the difference immediately: the screws thread in smoothly, with a solid metal-on-metal feel. No resistance from wood fibers, no risk of cross-threading. Just a clean, tight connection.

Step 6: Check Your Work

• Neck plate: Should sit flat against the body with no gaps
• Neck alignment: Strings should run parallel to the fretboard edges. If the neck shifted, loosen the screws and reposition
• Screw heads: Should be flush with the neck plate — not sticking up, not sunk too deep
• Play it: You may notice improved sustain and attack right away. The neck-to-body joint is now metal-on-metal, creating a more rigid, resonant connection

Sizing Quick Reference

Always measure your existing screws before ordering. Guitar manufacturers aren’t always consistent — even two of the same model can use different screw lengths.

Common Mistakes to Avoid

Drilling too deep. Mark your depth with tape. The insert max depth is 11mm for M4, 12mm for M5. Never exceed this going deeper risks drilling through the fretboard.

Driving the insert at an angle. Use the mounting tool. Trying to eyeball it with pliers almost always results in a tilted insert.

Overtightening the final screws. Snug is enough. The beauty of machine screws is that they don’t need to be cranked — the metal threads hold without brute force.

Using the wrong drill bit size. Too small and the insert won’t go in (or you’ll crack the wood forcing it). Too large and the insert won’t grip. Check the size chart above.

Skipping the measurement step. M4 x 45mm is the most common, but not universal. Five minutes with a ruler saves a trip back to the shop.

That’s It

Twenty minutes. Four holes, four inserts, four screws. Your bolt-on neck now has the same fastening system that high-end builders have used for decades. Remove and reinstall the neck as many times as you want — the connection stays tight, the tone stays full, the wood stays undamaged.

Get your threaded insert kit →

Not sure which size fits your guitar? Contact us with your guitar model and we’ll help you pick the right one.

This guide applies to all Nectite threaded insert kits, including stainless steel, black, gold, nickel, hex-drive, and relic finishes. The installation process is identical for all finishes.