7 best guitar neck shims for low action adjustments

When a guitar becomes difficult to play because the strings sit too high off the fretboard, practicing quickly turns from a hobby into a chore. Rather than paying expensive shop fees for a professional setup, many homeowners discover that a simple neck shim can restore the instrument to playable condition. This guide examines the best options to help bring your guitar back into perfect alignment with minimal effort.

StewMac Tapered Shims: For Precise Angle Control

When a guitar neck pocket is uneven, a flat shim often fails to provide the necessary tilt to correct the string angle. StewMac tapered shims are designed with a specific slope, which allows for a more accurate adjustment of the neck’s pitch compared to makeshift DIY solutions.

These are crafted from hard maple, ensuring that the connection between the neck and the body remains acoustically resonant. Because they are precision-cut, they eliminate the “tone suck” often associated with using softer materials or multiple layers of material.

For households where performance matters more than extreme budget savings, these represent a gold standard. While they carry a higher price tag, the time saved by having a pre-tapered piece makes the investment worthwhile for serious hobbyists.

Fender Neck Shims: The Official Fender Guitar Fix

Fender offers proprietary micro-tilt shims that are engineered specifically for their standard neck pocket dimensions. These provide an exact fit for Stratocasters and Telecasters, removing the guesswork involved in measuring or cutting custom inserts.

The design relies on a durable, thin composite material that is both stable and resistant to warping over time. It is an ideal choice for the homeowner who values brand-consistent parts and wants a “set it and forget it” solution.

These shims are particularly effective for those maintaining a collection of instruments in a home studio. Relying on original equipment manufacturer parts ensures that the guitar remains authentic, which is a key consideration for long-term resale value.

MusicNomad Shim Kit: Great for Your First Setup

If the prospect of adjusting a neck angle feels intimidating, a comprehensive kit can provide the guidance needed to succeed. MusicNomad offers a multi-thickness set that allows for experimentation, ensuring the perfect height is reached through trial and error.

The kit includes various thicknesses of shims, enabling incremental changes that prevent over-correcting the action. This approach is perfect for busy households where patience is limited and a quick, effective adjustment is required to get back to playing.

The inclusion of instructional guidance makes this a superior choice for beginners. Having a set on hand means that if one guitar setup changes due to seasonal humidity shifts, the tools to fix it are already in the utility drawer.

Hosco Maple Shims: For a Natural Wood-to-Wood Fit

Hardwood remains the preferred material for many luthiers because it mimics the natural density of the guitar’s body and neck. Hosco maple shims provide this organic connection, ensuring that vibrations are transferred efficiently throughout the instrument.

These shims are durable and resist the crushing effect that can occur when neck bolts are tightened firmly. They are an excellent option for vintage instrument owners who want to maintain the integrity of their guitar’s construction.

Because they are made of solid wood, they are also easier to sand or trim if a custom fit is required for an odd-sized neck pocket. They represent a balance of traditional craftsmanship and modern convenience.

Allparts Maple Shims: A Trusted Luthier’s Staple

Allparts is a well-established name in the repair industry, providing parts that professional shops rely on daily. Their maple shims are consistent in thickness and quality, ensuring that every adjustment is predictable and reliable.

These are an excellent choice for the homeowner who prefers to buy once and avoid repetitive maintenance. By opting for a standard luthier-grade part, the likelihood of having to revisit the repair in six months is significantly reduced.

They are sold as simple, no-nonsense units that do exactly what is promised. While they lack the bells and whistles of a multi-kit, they are ideal for someone who already knows exactly what thickness is needed for their specific guitar.

BigRock Brass Shims: To Maximize Tone and Sustain

While wood is the traditional choice, brass is favored by players who believe that metal-to-metal contact enhances sustain and brightness. BigRock brass shims offer a rigid, non-compressible solution that locks the neck firmly into the pocket.

These are particularly useful for guitars that feel slightly “dead” or lack the punchy response players desire. Because brass does not compress or warp under humidity changes, the action will remain stable throughout the year, even in climates with fluctuating temperatures.

Installation requires careful attention to alignment, but the result is a rock-solid platform for the neck. They are a practical upgrade for someone looking to subtly tweak the sonic character of their instrument while fixing action issues.

KAISH Wood Shims: A Practical and Affordable Pack

For those managing multiple guitars on a limited budget, KAISH offers a bulk-friendly set of wood shims. These are ideal for the household with several entry-level instruments that might all need a little help in the playability department.

The pack includes a variety of shapes and thicknesses, making it a versatile resource for standard bolt-on necks. It is a cost-effective solution for parents fixing up instruments for children or hobbyists learning the ropes of guitar repair.

While they may not offer the precision-engineered tapers of high-end brands, they provide a solid wood foundation at a fraction of the cost. They are the definition of a practical household supply.

Is a Neck Shim the Right Fix for Your Guitar?

Before installing a shim, verify that the issue is indeed the neck angle rather than a simple bridge adjustment. If the bridge saddles are already as low as they can go and the strings still feel like they are too far from the frets, a shim is the logical next step.

• Check bridge height: If there is plenty of room left on the bridge adjustment screws, turn those first.
• Inspect neck relief: A bowed neck often mimics the feel of high action; ensure the truss rod is adjusted correctly before reaching for a shim.
• Assess neck stability: If the neck pocket is loose or the bolts appear loose, a shim can also help provide a tighter fit.

Installing a shim is a reversible process, making it a low-risk experiment for most owners. If the change does not improve the feel, the shim can be removed without damaging the instrument.

Wood, Plastic, or Brass: Which Shim Is for You?

The choice of material often comes down to personal preference and the specific needs of the instrument. Wood is the standard for those seeking a natural, traditional sound, while brass is preferred for stability and enhanced resonance.

• Wood (Maple): Best for vintage instruments and those seeking a traditional, resonant feel.
• Plastic/Composite: Best for ease of use and consistent, maintenance-free performance.
• Brass: Best for maximizing sustain and ensuring the neck remains fixed under varying conditions.

For most casual players, a wood shim is the most reliable choice as it is easy to work with and integrates seamlessly into the guitar’s structure. Regardless of the material, ensure the shim is flat and matches the dimensions of the neck pocket as closely as possible.

How to Safely Install a Shim: A Quick Guide

The installation process begins by loosening the strings just enough to provide slack, then removing the neck plate and unscrewing the neck bolts. Carefully tilt the neck away from the body, ensuring you do not pull it so far that the wires to the pickups are strained.

• Clean the pocket: Remove any debris or old residue before placing the new shim.
• Align the holes: Ensure the holes in the shim line up perfectly with the holes in the neck pocket; misaligned bolts can damage the wood.
• Reattach securely: Tighten the bolts in an X-pattern to ensure even pressure across the joint.

Once the shim is in place, tighten the strings and check the action at the 12th fret. If the action is still too high or has become too low, you may need to adjust the thickness or use a tapered shim to achieve the desired angle.

Properly adjusting your guitar’s neck with a quality shim is a rewarding maintenance task that significantly improves your daily playing experience. By selecting the right material and following these straightforward installation steps, you can save money while keeping your instrument in top-performing condition. Take your time during the setup process, and you will find that a well-adjusted guitar is a joy to play for years to come.