Guide · Miter gauges, T-track and stops
Setup bars for bit height and fence distance
Setup bars are fixed-size references for bit height and bit-to-fence distance. What Kreg lists for its PRS3400 set, and how bars relate to lift dials and fence scales.
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Short answer
Setup bars are fixed-size references for setting bit height and the distance from the bit to the fence. Kreg's PRS3400 set has seven bars from 1/8 to 1/2 in in 1/16 in steps. Kreg publishes the sizes but no tolerance, so treat them as a reference, not a gauge with a stated accuracy.
What setup bars are
Setup bars are small bars machined to marked sizes. You stand one on the table next to the bit and raise the bit until it meets the bar's height, or set one flat between the bit and fence to set that distance. They give you a repeatable starting point without reading a ruler.
Kreg PRS3400: what Kreg lists
Kreg's Precision Router Table Setup Bars (PRS3400) are seven anodized aluminum bars sized 1/8, 3/16, 1/4, 5/16, 3/8, 7/16 and 1/2 in, stored in a case. Kreg lists them for setting bit or blade height, checking cut depth and setting the bit-to-fence distance.[1]
| Bar (in) | Kreg's metric equivalent |
|---|---|
| 1/8 | 3 mm |
| 3/16 | 4 mm |
| 1/4 | 6 mm |
| 5/16 | 8 mm |
| 3/8 | 9 mm |
| 7/16 | 11 mm |
| 1/2 | 12 mm |
Kreg lists those metric equivalents.[1] They are rounded labels: 1/8 in is 3.175 mm, not exactly 3 mm. Kreg says the bars are the same thickness, with a foot on one end marking the size.[1]
Kreg publishes no tolerance or accuracy figure for these bars.[1] Without a published tolerance, we make no claim about how close each bar is to its marked size.
How bars relate to lift dials
A router lift's dial and a setup bar do different jobs.
- A dial moves the bit by a known amount from wherever it is now. JessEm's Mast-R-Lift II and Rout-R-Lift II manuals both say one full turn of the height handle equals 1/16 in.[2] Kreg says the PRS5000 dial has markings every 1/64 in, with one full revolution equal to 1/16 in.[3]
- A bar gives a fixed height to set the bit to. It does not depend on where the bit started.
The dial figures are mechanism figures from the makers: how far the screw moves per turn. They are not measured accuracy. Our lift adjustment specs guide covers what those numbers mean.
A common workflow is to set a starting height against a bar, then use the dial for small changes after a test cut. Neither tool replaces the test cut.
Fence references
Bars set the bit-to-fence distance in fixed steps. Some fences have their own scales:
- Woodpeckers says the SF-PRO Universal has 0.001 in (0.025 mm) micrometer dial graduations on both infeed and outfeed fences.[4]
- INCRA says the LS Positioner places the fence at any multiple of 1/32 in, or 1 mm on metric models.[5]
These are graduations and positioning steps as the makers state them, not measured accuracy. See split vs single-face fences for more on fence adjustment.
Do you need a set?
Setup bars help most when:
- your lift or table has no dial, or the dial is hard to read;
- you repeat the same few heights often;
- you want to set the bit-to-fence distance without a ruler.
If your lift has a dial and you are happy zeroing it at the table surface, bars are optional. Whatever you use, check the first cut on scrap.
No setup bar set is in our approved catalog yet. When you shop for one, look for a listing that states the bar sizes and any tolerance the maker publishes.
Next
Questions
What are router table setup bars?
Bars of fixed, known sizes that you stand next to the bit or between the bit and fence as a height or distance reference. Kreg's PRS3400 set has seven anodized aluminum bars from 1/8 to 1/2 in in 1/16 in steps.[1]
Are setup bars accurate?
Kreg publishes no tolerance or accuracy figure for the PRS3400 bars, so we cannot say how close each bar is to its marked size.[1]
Do I need setup bars if my lift has a dial?
A dial moves the bit by a known amount from wherever it starts; a bar gives you a fixed size to set it to. Many readers use the bar to set a starting height and the dial for small changes. Neither replaces a test cut.
Do setup bars come in metric sizes?
Kreg lists metric equivalents of 3, 4, 6, 8, 9, 11 and 12 mm for its seven PRS3400 bars.[1]