# Ribbed plastic expansion anchors (wall plugs): drill size, length and screw range

> What drill bit and screw size does a ribbed plastic expansion anchor (wall plug) need?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: fischer SX Plus article table and Rawlplug UNO datasheet. Neither maker prints rib geometry, a collar diameter or a wall-thickness range, so no file
- Page: https://xemstudio.com/objects/ribbed-plastic-expansion-anchors/ · JSON: https://xemstudio.com/api/geometry?object=ribbed-plastic-expansion-anchors · Plain text: https://xemstudio.com/objects/ribbed-plastic-expansion-anchors/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
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**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- A ribbed plastic expansion anchor is a plug with ribs along its body: you drill a hole of the plug's diameter, push the plug in and drive a screw that spreads it against the hole wall. Tables below are two makers' published sizes (mm, inch in brackets, computed as mm / 25.4).
- Drill size d0 equals the plug diameter in both makers' tables (a 6 mm plug takes a 6 mm hole). The hole must be deeper than the plug: the maker's minimum drill depth (h1 / h0) is the plug length plus 10 mm for every Rawlplug UNO size and for fischer SX Plus up to 8 × 65, and plus 20 mm for SX Plus 10 × 50 and 12 × 60.
- The screw range is the thread diameter the maker prints for that plug (wood or chipboard screw). Rawlplug prints one diameter per pack, so some sizes show a single value.
- Not published and therefore not on this page: rib or fin dimensions, collar (flange) diameter, and a plasterboard or wall thickness range. These plugs are specified for the substrate depth of the hole, not the panel thickness; for thin panels see the plywood and drywall page and use a hollow-wall anchor.

## Sizes

| maker / series | size (plug mm × length mm) | drill d0, mm (in) | min. hole depth, mm (in) | plug length, mm (in) | screw diameter, mm |
|---|---|---|---|---|---|
| fischer SX Plus | 4 × 20 | 4 (0.157) | 30 (1.181) | 20 (0.787) | 2.0 – 3.0 |
| fischer SX Plus | 5 × 25 | 5 (0.197) | 35 (1.378) | 25 (0.984) | 3.0 – 4.0 |
| fischer SX Plus | 6 × 30 | 6 (0.236) | 40 (1.575) | 30 (1.181) | 4.0 – 5.0 |
| fischer SX Plus | 6 × 50 | 6 (0.236) | 60 (2.362) | 50 (1.969) | 4.0 – 5.0 |
| fischer SX Plus | 8 × 40 | 8 (0.315) | 50 (1.969) | 40 (1.575) | 4.5 – 6.0 |
| fischer SX Plus | 8 × 65 | 8 (0.315) | 75 (2.953) | 65 (2.559) | 4.5 – 6.0 |
| fischer SX Plus | 10 × 50 | 10 (0.394) | 70 (2.756) | 50 (1.969) | 6.0 – 8.0 |
| fischer SX Plus | 12 × 60 | 12 (0.472) | 80 (3.15) | 60 (2.362) | 8.0 – 10.0 |
| Rawlplug UNO | Ø5 | 5 (0.197) | 34 (1.339) | 24 (0.945) | 3.5 |
| Rawlplug UNO | Ø6 | 6 (0.236) | 38 (1.496) | 28 (1.102) | 4.0 |
| Rawlplug UNO | Ø8 | 8 (0.315) | 42 (1.654) | 32 (1.26) | 4.5 – 5.0 |
| Rawlplug UNO | Ø10 | 10 (0.394) | 46 (1.811) | 36 (1.417) | 5.0 – 6.0 |

## Where the files are

- fischer: [Expansion plug SX Plus: article table (drill diameter d0, min. drill hole depth h1, anchor length l, screw diameter ds)](https://www.fischer.co.uk/en-gb/products/standard-fixings/plastic-fixings/expansion-plug-sx-plus) — web — Publisher's page; dimensions are facts
- Rawlplug: [UNO Universal Plug with Screw: product information and installation data (d, l, D, d0, h0)](https://static.chipdip.ru/lib/417/DOC025417841.pdf) — web — Maker datasheet, hosted by a distributor; numbers only

## Questions

**Which drill bit for a ribbed plastic expansion anchor?**

The bit equals the plug diameter: 5, 6, 8, 10 mm (0.197, 0.236, 0.315, 0.394 in) for the sizes above; 4 mm for fischer SX Plus 4 × 20 and 12 mm for 12 × 60.

**What wall thickness do these plugs need?**

Neither maker prints a wall or panel thickness range. The published figure is the minimum drill hole depth, which is the plug length plus 10 mm (plus 20 mm for fischer 10 × 50 and 12 × 60).

## Fits with

- [Plywood and drywall sheets: 4 × 8 ft at actual thickness (3/4 in plywood = 23/32 in)](https://xemstudio.com/objects/plywood-and-drywall/)