Guide · Miter gauges, T-track and stops
The 3/4 x 3/8 in miter slot: actual widths, T-slots and fit
Most gauges and featherboards in our sources fit a 3/4 in wide, 3/8 in deep slot. The actual-width ranges INCRA, Bosch, Kreg and Bow state, and how to measure yours.
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Short answer
Most miter gauges and featherboard bars in our sources are made for a slot 3/4 in wide and 3/8 in deep, with or without a T-slot at the bottom. "3/4 in" is nominal, so check your slot's actual width against the range each gauge maker states.
The nominal slot
A miter slot is a straight groove in the table top, parallel to the fence, for a miter bar to ride in. The common size is 3/4 in wide by 3/8 in deep, the same nominal size most table saws use.
Bosch says the RA1181's aluminum miter gauge slot works with most stationary table saw miter gauges that measure 3/4 in wide x 3/8 in deep. No miter gauge is supplied.[1] Bosch also describes the RA1181 as having an accessory slot for 3/4 in accessories.[2]
Actual widths: each maker's range
A slot sold as 3/4 in can measure a little under or over. Gauge makers handle that with expanding discs or adjusters, and each states the range it covers.
| Gauge or document | Actual width the maker states | Depth | T-slot |
|---|---|---|---|
| INCRA Miter 1000SE | 0.740 to 0.765 in | 3/8 in | With or without a 15/16 in T-slot |
| INCRA Miter Slider SE (18 in and 25.5 in bars) | 0.740 to 0.765 in | About 3/8 in | With or without a 15/16 in wide T-slot |
| INCRA Miter 3000SE compatibility checker | 0.740 to 0.770 in | 0.375 in minimum | Optional, 1/8 in high x 15/16 in wide |
INCRA says the Miter 1000SE is designed for square-sided slots 3/4 in wide and 3/8 in deep, with or without a 15/16 in T-slot at the bottom, and adjusts to actual widths of 0.740 to 0.765 in.[3]
INCRA's Miter Slider SE comes in 18 in (IMS1SE) and 25.5 in (IMS2SE) lengths and adjusts to the same 0.740 to 0.765 in range.[4]
INCRA's Miter 3000SE compatibility checker lists a 3/4 in typical slot width (0.740 to 0.770 in actual), a depth of 0.375 in minimum, and an optional T-slot area 1/8 in high x 15/16 in wide.[5] That range is for the 3000SE only. Keep each range with its own model.
Featherboard bars use the same slot
| Featherboard | Slot fit the maker states |
|---|---|
| Kreg True-FLEX (PRS3010) | 3/8 x 3/4 in miter slots and T-slots, with Wedge-Lock hardware |
| Bow FeatherPRO (FP1) | 3/4 in AnchorPRO bar for 3/8 x 3/4 in slots |
| Bow FeatherDUO (FP3) | Two 3/4 in AnchorPRO bars for 3/8 x 3/4 in slots |
Kreg lists the True-FLEX for 3/8 x 3/4 in miter slots and T-slots, on table saws or router tables.[6] Bow's FeatherPRO comes with a 3/4 in AnchorPRO miter bar for 3/8 x 3/4 in slots[7], and the FeatherDUO uses two of them.[8] More on mounting in our featherboard mounting guide.
What a T-slot is
A T-slot miter slot has a wider channel at the bottom, so the slot's cross-section looks like an upside-down T. A bar with a matching foot or retaining clips cannot lift out of it. The INCRA gauges above fit slots with or without a 15/16 in wide T-slot. A plain rectangular slot works too; you just lose the hold-down effect.
How to measure your slot
You need calipers. Measure, do not assume:
- Width at the near end, the middle and the far end of the slot, at the top edge.
- Depth from the table surface to the slot floor, in two or three places.
- T-slot: whether the slot widens at the bottom, and how wide the channel is if it does.
Write down the narrowest and widest width. A gauge fits when both fall inside its maker's range. If your slot measures 0.760 in, all three INCRA ranges above include it. If it measures 0.768 in, only the Miter 3000SE checker's range does.
Gauges and track for a 3/4 x 3/8 in slot
Picks that fit3 products
Kreg KMS7102: a miter gauge with a 24 in fence and swing stop, for 3/4 x 3/8 in slots. POWERTEC 71391: a miter gauge kit with a 24 in fence and flip stop, for 3/4 x 3/8 in slots with or without a T-slot, not 5/8 in slots.
More on choosing
POWERTEC 71568: a 32 in miter track with a T-bar, only if you are building a top that needs a 3/4 x 3/8 in slot. Measure your slot against each maker's listing first. On Amazon, check that Ships from / Sold by is Amazon.com or the brand.
Gauge with a long fence and swing stop
Gauge for slots with or without a T-slot
POWERTEC 71391 precision miter gauge system with 24 in multi-track fence and flip stop
Add a slot to a shop-made top, with a bar
Next
Questions
What size is a router table miter slot?
The gauges and featherboards in our sources are made for a slot 3/4 in wide and 3/8 in deep, with or without a T-slot at the bottom. Bosch says the RA1181's slot works with most stationary table saw miter gauges of that size. Measure your own slot to confirm.[1]
Will my table saw miter gauge fit my router table?
If your router table's slot is 3/4 x 3/8 in and its actual width falls inside the gauge maker's range, it should be within the maker's stated fit. Bosch says the RA1181 slot works with most stationary table saw miter gauges that size; no miter gauge is supplied with it.[1]
What is a T-slot miter slot?
A slot with a wider channel at the bottom, so a bar with a T-shaped foot or retaining clips cannot lift out. INCRA describes its gauges as fitting slots with or without a 15/16 in wide T-slot.[3]