# Adafruit SHT31-D temperature & humidity sensor (#2857, STEMMA QT): 25.4 × 17.78 mm board and 4 mounting holes

> What are the Adafruit SHT31-D (product 2857) breakout dimensions and mounting-hole positions?

- Category: Electronic components › Modules, sensors & displays
- Kind: Modern device
- Basis: Adafruit's EagleCAD board file for the SHT31-D STEMMA QT breakout, with connector height from the JST SH datasheet.
- Page: https://xemstudio.com/objects/adafruit-sht31-d-2857/ · JSON: https://xemstudio.com/api/geometry?object=adafruit-sht31-d-2857 · Plain text: https://xemstudio.com/objects/adafruit-sht31-d-2857/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 25.4 | 17.78 | 4.55 |

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

## Notes

- Board 25.40 × 17.78 with R2.54 corners, centred, board bottom at 0; the header edge is −Y. Board thickness 1.6 is assumed (Adafruit's board file does not state it); everything else is from the board file.
- Four mounting holes on a 20.32 × 12.70 rectangle: two plated Ø2.50 at (±10.16, +6.35) and two unplated Ø2.54 at (±10.16, −6.35).
- Two STEMMA QT (JST SH 4-pin) connectors on the short edges, openings facing outward; 4.55 overall height.
- Not modelled: the loose 1×7 0.1 in header along the −Y edge and the 2.5 × 2.5 SHT31 sensor; leave the sensor open to air.
- This is the current STEMMA QT revision; older non-STEMMA SHT31-D boards may differ.
- All dimensions are exact nominal millimetres, true size, with no tolerance added.

## 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 |
|---|---|---|---|---|
| Mounting holes | 2 × Ø2.50 + 2 × Ø2.54 on 20.32 × 12.70 | M2.5 or #2-56 screws and standoffs | designed | all |
| STEMMA QT connectors | 2 × JST SH 4-pin, 4.25 × 6.10, top 4.55, openings on both short edges | JST SH 4-pin cable plug; leave cable clearance past each short edge | designed | all |

## Sizes

| hole | x (mm) | y (mm) | diameter (mm) | type |
|---|---|---|---|---|
| 1 | -10.16 | -6.35 | 2.54 | unplated |
| 2 | +10.16 | -6.35 | 2.54 | unplated |
| 3 | -10.16 | +6.35 | 2.50 | plated |
| 4 | +10.16 | +6.35 | 2.50 | plated |

## Where the files are

- Adafruit: [Sensirion SHT31-D Temperature & Humidity Sensor Breakout (#2857)](https://www.adafruit.com/product/2857) — web — Publisher's page; dimensions are facts
- Adafruit: [Adafruit-SHT31-Sensor-Breakout-PCB repository](https://github.com/adafruit/Adafruit-SHT31-Sensor-Breakout-PCB) — web — Publisher's page; dimensions are facts
- Adafruit Learning System: [Adafruit SHT31-D Temperature & Humidity Sensor Breakout guide](https://learn.adafruit.com/adafruit-sht31-d-temperature-and-humidity-sensor-breakout) — web — Publisher's page; dimensions are facts
- JST: [SH connector series datasheet](https://www.jst-mfg.com/product/pdf/eng/eSH.pdf) — web — Publisher's page; dimensions are facts

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

Index: https://xemstudio.com/files/hardware/adafruit-sht31-d-2857/index.json

- adafruit-sht31-d-2857: [STEP](https://xemstudio.com/files/hardware/adafruit-sht31-d-2857/adafruit-sht31-d-2857.step) · [STL](https://xemstudio.com/files/hardware/adafruit-sht31-d-2857/adafruit-sht31-d-2857.stl) — Adafruit SHT31-D temperature & humidity sensor (#2857, STEMMA QT): 25.4 × 17.78 mm board and 4 mounting holes

## Questions

**How big is the Adafruit SHT31-D breakout?**

25.40 × 17.78 mm, 1.6 mm board (assumed), 4.55 mm tall over the STEMMA QT connectors.

**Are all four mounting holes the same size?**

No: two plated Ø2.50 holes on one long side and two unplated Ø2.54 on the other, all on a 20.32 × 12.70 mm rectangle.

## Fits with

- [Adafruit STEMMA QT sensor breakouts (BME280, BNO055/085, VL53, SCD-40, AHT20, SHT40, IMUs, light, magnet, RTC…)](https://xemstudio.com/objects/adafruit-stemma-qt-breakouts/)
- [JST SH connector (1.0 mm pitch): wire, ratings, circuits](https://xemstudio.com/objects/jst-sh-connector/)
- [Threaded standoffs, M2.5 and M3 (hex and round)](https://xemstudio.com/objects/threaded-standoffs-metric/)
- [2.54 mm pin headers, 1×2 to 2×20, vertical and right-angle](https://xemstudio.com/objects/pin-headers-2.54mm/)
- [Adafruit VL53L0X ToF distance sensor (#3317, STEMMA QT): 25.4 × 17.78 mm board, 4 mounting holes and sensor window](https://xemstudio.com/objects/adafruit-vl53l0x-3317/)
- [Adafruit BME280 breakout (original)](https://xemstudio.com/objects/adafruit-bme280-breakout-original/)