How to Cut a Bridge for a Guitar

Making an acoustic bridge saddle is a task suitable for a beginning guitar repairman.

Acoustic guitars utilize a strip of bone or plastic for a bridge. The bridge, typically called a bridge saddle, rests in a slot on the bridge plate. You must cut the bridge saddle to fit the slot in the bride plate. You must also trim the bridge saddle’s height so the strings rest at the appropriate height above the frets on the guitar neck. This will ensure the guitar’s intonation is correct.

Things You'll Need

• Bridge saddle blank
• Vise
• Coping saw or jeweler's saw
• 600-grit, 800-grit and 1000-grit sandpaper
• Feeler gauge set
• Plate glass

Instructions

1. Place the bridge saddle blank over the slot on the bridge plate and mark each end of the slot onto the bridge saddle blank.

2. Position the bridge saddle blank in a vise with the line on one end of the saddle resting flush with the side of the vice. The vise will help you keep a straight cut.

3. Cut the excess saddle material off with a coping saw or jeweler’s saw.

4. Flip the bridge saddle around, line the line on the other end of the saddle up with the side of the vise and then cut that end of the saddle blank off.

5. Sand the edges of the saddle with 600-grit, 800-grit and then 1000-grit sandpaper to smooth the cut edges. Round over all sharp corners on the saddle with the sandpaper.

6. Place the bridge saddle into the slot on the bridge plate.

7. String the guitar and tune it to pitch.

8. Measure the distance between the bottom of the Low E (largest) string and the 12th fret on the neck with a feeler gauge. The appropriate height is .100 inch. Subtract .100 inch from the actual measurement. The resulting number is the amount you must shave off the bottom bass side of the bridge.

9. Measure the distance between the bottom of the High E (Smallest) string and the 12th fret on the neck with a feeler gauge. The appropriate height is .075 inch. Subtract .075 inch from the actual measurement. The resulting number is the amount you must shave off the bottom treble side of the bridge.

10. Loosen the strings and remove the bridge saddle from the bridge plate.

11. Measure up from the bottom of the bridge saddle to the number you obtained in Step 8 and place a mark on the bass end of the bridge saddle. The bass end is the end that rests under the Low E string. Measure up from the bottom of the bridge saddle to the number you obtained in Step 9 and place a mark on the treble side of the bridge saddle. Draw a straight line between both numbers.

12. Tape a piece of 600-grit sandpaper onto a piece of plate glass. Plate glass is very flat and makes an idea sanding surface.

13. Place the bottom edge of the bridge saddle onto the sandpaper and sand the saddle until you reach the line you drew.

14. Place the saddle back into the bridge plate and then tune the guitar to pitch.

References

• "Guitar Player Repair Guide"; Dan Erlewine; 1994
• Thomas Becker: Setting the Saddle Height