StewMac Refret Saw Review: Essential Fret Slot Deepening Tool
(This is NOT a sponsored review, I just want to give my thoughts on the tool so beginners have enough information to make an informed decision)
When it comes to guitar restoration and fret work, having the right tools makes all the difference. The StewMac Refret Saw is one of those specialty tools that might look weird an unnecessary at first glance, but once you use it you’ll understand why it’s essential for fret slot maintenance and repair.
Understanding Fret Slot Dimensions and Why Precision Matters
Fret slots are incredibly narrow, typically around 0.6mm / 0.023″ wide. This tiny width is why you can’t just grab any saw, even if it’s a “hand woodworking quality” saw. A standard saw blade will enlarge the slot, ensuring that the frets will not have a proper slot to stay seated in the fretboard. The StewMac Refret Saw is specifically designed to allow you to deepen or clean fret slots without accidentally widening them.
Before You Start: Checking Fret Slot Depth with a Gauge
Before using the saw, you need to check your current fret slot depth. A fret slot depth gauge (available from StewMac and other suppliers) lets you quickly assess whether a slot has adequate depth. Simply insert the gauge into the slot and observe:
- If the slot is shallow or uneven, it needs deepening
- If you’ve recently sanded your fretboard, checking every slot is recommended
- Slots that have been partially filled with finish or debris should be cleaned out
How the Refret Saw Works
The design of the refret saw is that it has two saw blades, one on each end:
- Pull stroke end: the blade where teeth that point towards you
- Push stroke end: the blade where the teeth point away from you
Step-by-Step: Deepening a Fret Slot
Once you’ve identified the slots that need work:
- Start with light scoring: Begin with gentle, controlled strokes, both push and pull, to score the slot slightly deeper.
- Keep pressure consistent: This is a finesse tool, not a power tool. Aggressive pressure won’t speed up the work and risks crossing into the surrounding fretboard.
- Stay within the slot: The entire goal is to remain inside the existing slot boundaries. One slip outward creates visible damage on the fretboard surface.
- Check depth frequently: Periodically stop and use your fret depth gauge to measure progress. You’ll be surprised how much material you remove with light strokes.
- Make multiple passes: Repeat the gentle push-pull motions until the slot reaches proper depth.
Cleaning Out Debris
After sawing, fret slots often contain sawdust, old finish, or other debris. Be sure to clean out the slots using compressed air, a brush (I use an old paint brush to great effect), a razorblade…whatever it takes to make sure the fret slot is free from interference.
When the Refret Saw Becomes Indispensable: Refretting Bound Necks
The StewMac refret saw truly shines when working on guitars with fretboard binding or other edge details. On a bound fretboard, you cannot simply run a standard saw blade all the way across because you’d cut into the binding channel itself. The precision of the refret saw keeps your work confined to the fret slots, protecting decorative or structural binding.
This makes it an essential tool for anyone restoring vintage guitars or working with premium instruments where binding is a design feature.
Is It Worth the Investment?
Yes, especially if you’re working on existing necks. The StewMac Refret Saw is a legitimate bargain for specialty luthier work. Unlike a general woodworking chisel (which you can find anywhere), this tool has a single, critical purpose, and it does that job better than any makeshift alternative. If you’re building guitars or restoring vintage instruments, it belongs in your workshop.
The reality is that this tool has almost no use outside of guitar fret work. But if you’re in this hobby seriously, that narrow specialization is exactly the point.
Frequently Asked Questions
Can I Use a Regular Saw to Deepen Fret Slots?
Almost certainly not. Standard saw blades are too thick, and the fretwire will not stay friction-fit in the slots.
How Often Do Fret Slots Need Deepening During a Refret?
If you’re replacing frets on a vintage guitar, nearly every slot may need some attention, especially if the fretboard has been sanded or has uneven wear. Use your depth gauge to check systematically rather than guessing.
Can This Tool Damage Fretboard Binding?
Not if you’re careful to stay within the slot. The narrow blade and your controlled technique keep the work isolated to the fret slot itself, protecting binding on either side.
What’s the Learning Curve for Using This Saw?
It’s surprisingly quick. The main skill is learning to apply light, consistent pressure and keeping your strokes aligned with the slot. Most people get comfortable with it within their first or second fret slot.
The Takeaway: Specialty Tools for Specialty Work
The StewMac Refret Saw is specialty luthier tool that you simply can’t substitute with general woodworking gear. When you need to precision-deepen a fret slot without enlarging it, this tool is the right tool for the job.
See the Full Process
The complete discussion of the refret saw is on the Zwitch Guitars YouTube channel
Questions about refretting a guitar? Leave a comment on the video or get in touch through the contact page.
