Piano Voicing Pliers

Instruction Video

Piano Voicing Tool Instructions

Hammer Side-Voicing Tool Instructions

The Prime Piano Hammer Side-Voicing Tool is particularly well-suited for voicing older hammers, and will greatly facilitate the voicing of upright pianos. It can as well be used cautiously for pre-voicing of new hammers. Note: Renner does not recommend side-voicing on their Premium Blue Hammers. If in doubt with other hammers, refer to the manufacturer for details.

Tool Setup

The tool will accommodate all standard voicing needles, comprising #1 (.9mm / 0.036”), #2 (.8mm / 0.032”), #5 (.76mm / 0.030”), #6 (.68mm / .027”), #7 (.65mm / 0.026”), as well as #5 and #6 Glover Needles. It can be used with one, two, or three needles as desired.

  1. With the set screws loosened appropriately, insert a needle through the horizontal hole.
  2. Tighten the set screw on one side of the jaw until it just contacts the needle.
  3. Adjust the needle protrusion to the desired depth of penetration. Maximum Depth should not exceed 1/2 the thickness of the hammer (about 5/16"), and initial passes should begin with shallow needling.
  4. Tighten the opposing set screw to secure the needle.
  5. Insert additional needles as desired to matching depth.
  6. Clip off the protruding needle shank on the other side of the jaw.

General Guidelines

  1. When voicing hammers already installed in the piano, use the solid, non-needled jaw of the tool as a support held tightly against the opposite side of the hammer. Hold this supporting jaw firmly against the hammer as illustrated below to avoid damage to the action pinning.
  2. Equal stitches should be applied to each side of the hammer. The first pass of stitches should be shallow to judge the effects on the tone.
  3. Generally, 3 needles should be used on large or bass hammers, and the number of needles is reduced as the hammer size diminishes or as the technician desires.
  4. The initial voicing should be halfway between the hammer core and the strike point, and should begin with shallow needle depth.
  5. If the desired effect is not achieved, the needling may be moved a bit closed to the strike-point and needle depth may be increased. Discretion and progressive testing should be done to judge the tone improvement and quality.
  6. Do not attempt to use the tool for traditional voicing around the arc of the strike point, as this may cause the needles to bend or break.
  7. Additional fine-tuning may be applied as desired with traditional needling tools and techniques.

Side Voicing Simplified


These lateral voicing pliers fit in places others simply cannot. The technician’s skilled hands and fine touch control the insertion and retraction of the needles, while facility with the tool comes quickly and with ease.

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Ease of Use

Each side of the hammer is voiced separately. Penetration is half the distance of the hammer width. Results are fast, safe and outstanding! Voicing is simple even in difficult, time-consuming upright actions.

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Quality Design

Finest Quality Tool Design and Machining. Rugged Stainless Steel construction. Beautifully handcrafted by makers of optical and surgical instruments. Lifetime replacement warranty.

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