Rear Peghole Reamer

  • 24 Reviews
  • Write a review

Counterbores the back of a 5/16"-diameter peghole to fit a Grover, Schaller or Gotoh sealed gear housing.

Read more

Rear Peghole Reamer

Item # 2059
In stock, ready to ship!


Total: $0.00
Quantity: 20


Counterbores the back of a 5/16"-diameter peghole to fit a Grover, Schaller or Gotoh sealed gear housing.

For Grover, Schaller and Gotoh sealed tuners!
Here's a tip from our luthier friend Bryan Galloup: Grover, Schaller and Gotoh tuners with threaded bushings should be installed in counterbored pegholes. A snug 5/16" diameter at the top of the hole stops the bushing from leaning under string pull, thus helping to protect the lacquer finish around the bushing washers. At Bryan's suggestion, we developed this special slow-speed steel reamer that accurately counterbores the bottom of the peghole to fit the gear housing.

The reamer has a .310"-diameter (7.87mm) pilot and two flutes that cut a .397"-diameter (10.08mm) counterbore in a 5/16"-diameter (7.94mm) peghole. When the reamer's piloted end is flush with the face of the peghead, the correct counterbore depth has been reamed.

Ratings & Reviews

Rear Peghole Reamer

  • Based on 24 Reviews
Displaying 1 of 3 1 2 3
Write a review

Works great!

By Layne guitars from Utah
(Customer's Reviews) Wednesday, December 03, 2014

I used this reamer in my drill press on the lowest speed. It worked great! It automatically reams the correct depth. Just send it through until it stops. Easy!

Worth every dollar and much more

By Ariel from ashkelon ISR
(Customer's Reviews) Sunday, November 16, 2014

This reamer is amazing, it's the most accurate tool for the job. Haven't slept for a few days knowing that I have to drill the headstock of a new Les Paul custom shop to fit Grovers... all those stories about cracked headstocks... a nightmare!!!
Finally the reamer arrived and in 2 minutes - JOB DONE!!!
The tuners fit perfectly in the holes!!! Thank you Stewmac!!!!
Gonna have a good night sleep today!!!


By PolymathicGuy from Logan, UT
(Customer's Reviews) Friday, May 23, 2014

This is truly an excellent tool - very high quality and worked perfectly to help me change my stock tuners out to Grovers on my Les Paul Classic.

Well worth it!

By Turko from San Diego
(Customer's Reviews) Thursday, April 03, 2014

I hesitated before I bought this because of the price, but once I tried it I really liked it and now seriously recommend it. What used to be a tedious task has now become a breeze. Very accurate and easy to use.

Can I give this 6 stars?

By Gregory Wolff from Virginia
(Customer's Reviews) Sunday, January 05, 2014

This reamer is the perfect tool for upgrading an older guitar to a newer set of tuners. I used this bit on a very old Squier Strat. As mentioned by some other reviewers, use this bit slowly and you will have no problems at all with chips and tears. I used a small piece of scrap oak on the face of the peghead and used a cordless drill. Very slowly and smoothly, this bit cut out the perfectly sized holes for new tuners. When the bit hit the scrap wood on the other side, it stops cutting. This bit is an absolute must for ANYONE who does upgrades to older, less expensive guitars. Great job, StewMac! This item is a true winner!

A MUST-HAVE for retrofitting tuners

By bbrich57 from Austin, TX
(Customer's Reviews) Friday, February 15, 2013

I bought this tool several months ago as I do quite a few tuner upgrades. It was an "investment" I will never regret. I've done four 6-strings already using it. If the headstock is already drilled, just clamp a piece of scrap wood to the front and go!! That simple. Though I still use a chamfering tool to get the tool started and break the finish edge, this tool is self-guiding and self-stopping. As long as you're not an idiot and try to go 900 mph with it, you CAN'T make a mistake. It's as idiot proof a tool as I have ever owned and a real time/guess work saver too. Highly recommended.

Excellent tool!!

By ElectriCapricorn from SoCal
(Customer's Reviews) Tuesday, January 01, 2013

I'm currently building my first guitar, which is an SG clone. (The kit that I bought didn't specify what tuners the manufacturer intended for use, so I jumped the gun and bought a set of Grover Deluxe Keystones.) Anyway, after the tuners arrived, I quickly realized that I'd need to open up the pre-drilled holes in the headstock. I ordered this tool, and in five minutes I had the proper rear counter-bored holes in the headstock, and my tuners fit perfectly.

The Right Tool

By Tom Sawyer (really!) from Vernon, CT
(Customer's Reviews) Wednesday, November 28, 2012

Exactly the right tool for upgrading Squier (and such like) pegheads from those rickety 1/4" shaft gears to cast tuners!


By Randolph Guitars from Welch,OK
(Customer's Reviews) Wednesday, August 22, 2012

One word. Nice!

Must have item when installing Grover tuners

By Fast Robert from Indy
(Customer's Reviews) Wednesday, August 22, 2012

I bought this item in preparation to install Grover tuners on my acoustic guitar as a beta test to ultimately install Grovers on my Les Paul.

A forum post on clearly explained how to use the reamer and to NOT use a drill but a T handle hand drill instead. Being a little nervous about cutting into a perfectly fine headstock, I started slowly on the first hole. By the sixth hole, it was a piece of cake. Just take your time.

The reamer performed perfectly and the Grovers installed without issue.

It is a bit pricey however it is absolutely necessary.

Shipped and received quickly.

Displaying 1 of 3
1 2 3

Shown on page 21 of our latest catalog.