# T-slot tongue gauge 5.6 / 5.8 / 6.0 mm (6 mm slot)

> What tongue width slides in a 2020 extrusion slot when 3D printed?

- Category: Stirling engines › Generators & instruments
- Kind: Hardware
- Basis: Tongues stepped below the 6.0 mm slot opening of 20-series extrusion
- Page: https://xemstudio.com/objects/extrusion-tongue-gauge/ · JSON: https://xemstudio.com/api/geometry?object=extrusion-tongue-gauge · Plain text: https://xemstudio.com/objects/extrusion-tongue-gauge/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

**Exact dimensions.** Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part.

## Notes

- Every file on this site is drawn at exact size with no printing allowance; this gauge steps through sizes around the nominal so you can measure the allowance your process needs for one fit class, then apply it only to the features each object lists under Mating features.
- The gauge is a 60 × 30 × 3 mm plate with three tongues 20 mm long × 1.5 mm tall, 5.6, 5.8 and 6.0 mm wide, on 20 mm pitch.
- Slide each tongue into the slot of a 6 mm-slot extrusion: the widest one that slides, minus 6.0, is your tongue allowance (negative).

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| gauge sizes | stepped around nominal | the true pin, nut, bearing or extrusion slot being tested | designed | all |

## Sizes

| tongue | width_mm | length_mm | height_mm |
|---|---|---|---|
| 1 | 5.6 | 20 | 1.5 |
| 2 | 5.8 | 20 | 1.5 |
| 3 | 6.0 | 20 | 1.5 |

## Where the files are

- Wikipedia: [Engineering tolerance](https://en.wikipedia.org/wiki/Engineering_tolerance) — web — CC BY-SA 4.0 (text)
- Prusa: [Knowledge base: XY size compensation](https://help.prusa3d.com/article/xy-size-compensation_125045) — web — Prusa KB (verify at link)
- Long Earth Society: [Engine and rig builds](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (1 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/extrusion-tongue-gauge/index.json

- extrusion-tongue-gauge-6mm: [STEP](https://xemstudio.com/files/hardware/printer-calibration-coupons/extrusion-tongue-gauge-6mm.step) · [STL](https://xemstudio.com/files/hardware/printer-calibration-coupons/extrusion-tongue-gauge-6mm.stl) — T-slot tongue gauge: 5.6 / 5.8 / 6.0 mm tongues for a 6 mm slot

## How it fits

### Goes in or on
- [2020 aluminum extrusion](https://xemstudio.com/objects/2020-extrusion/): tongues slide in the 6.0 mm slot opening

### Connects to
- [Slide-in T-nuts for 20, 30, 40 and 10-series (1 in) extrusion](https://xemstudio.com/objects/slide-in-t-nuts/): the measured allowance applies to T-nut tongues

## Questions

**What width should a tongue be for a 2020 slot?**

The slot is 6.0 mm and the tongues are drawn at 6.0; this gauge shows how much narrower your process needs it.

**Does it work for 30- or 40-series?**

No; it is sized for the 6 mm slot of 20-series extrusion.

## Fits with

- [2020 aluminum extrusion](https://xemstudio.com/objects/2020-extrusion/)
- [Slide-in T-nuts for 20, 30, 40 and 10-series (1 in) extrusion](https://xemstudio.com/objects/slide-in-t-nuts/)
- [Aluminium T-slot extrusion: 2020, 2040, 2060, 2080, V-slot, 3030, 3060, 4040, 4080, 1010, 1515](https://xemstudio.com/objects/t-slot-extrusions/)
- [Hole gauges for Ø3, Ø5 and Ø8 (0.1 mm steps)](https://xemstudio.com/objects/hole-gauges/)