# Rivet nuts (blind threaded inserts), flat head: hole size, grip range, body and flange dimensions, M3–M12 and #6-32 to 3/8-16

> What hole size does a rivet nut need, and what are its flange diameter, length and grip range?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: Westfield Fasteners' flat-head knurled open-end table (zinc plated steel), PEM (Sherex) recommended hole chart, and an unnamed maker's inch large-flange datasheet; numbers only for the nuts, one hole-gauge plate as a file
- Page: https://xemstudio.com/objects/rivet-nuts-flat-head/ · JSON: https://xemstudio.com/api/geometry?object=rivet-nuts-flat-head · Plain text: https://xemstudio.com/objects/rivet-nuts-flat-head/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 |
|---|---|---|
| 131.7 | 32.1 | 3.0 |

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- A rivet nut (rivnut, blind threaded insert) is a flanged tube with an internal thread that is pulled up from the blind side of a sheet. The hole is round, the nut's body is a close fit in it, and the grip range is the sheet thickness the one nut length covers. Metric rows are Westfield's flat-head knurled open-end zinc steel table (mm); inch rows are a flat-head large-flange maker datasheet, max / min as printed. The 'in' rows are separate from the metric rows, not conversions.
- Hole diameter: Westfield prints 5.0, 6.0, 7.0, 9.0, 11.0, 13.0, 16.0 mm for M3 to M12; PEM (Sherex) recommends 5.1, 6.1, 7.1, 9.1, 11.1, 13.1, 16.1 mm ±0.1 mm for standard round-body nuts. The hole gauge uses the PEM numbers. PEM does not give hole sizes for hex, slotted, countersunk or low-profile bodies. Inch drill sizes are as printed on the datasheet (#12, #2, #E, #Q, #Z, 12.5 mm); their decimal sizes are not printed there, so none is shown.
- Length: the metric column is Westfield's 'Body Overall Length'. The same table also has a column headed 'length' that is not clearly defined, and for M5 0.5–2.5 mm it prints 14.0 against an overall length of 13.0, so that column is left out. The inch column is the datasheet's 'Body Length', and it does not say whether that is before or after installing.
- Flange OD and thickness differ by maker and finish, so check the maker of the nut you buy. Flange OD, in mm, M3 / M4 / M5 / M6 / M8 / M10 / M12: Westfield zinc 8.0 / 9.0 / 10.0 / 12.3 / 14.5 / 17.0 / 22.0; Westfield stainless 8 / 9 / 10 / 13 / 16 / 19 / 23; RS PRO A2 7.0 / 9.0 / 10.0 / 12.5 / 15.0 / 17.0 / 22.0. Body OD agrees in all of them (4.9, 5.9, 6.9, 8.9, 10.9, 12.9, 15.9 mm).
- Not on this page and not drawn: the internal thread depth, thread minor diameter and wall thickness (not printed), the knurl or hex pattern, the thickness at the flange fillet, and installed (collapsed) shape. The rivet nut itself is therefore not modelled; the file is a hole gauge. Westfield's stainless table has a printed M12 hole of 13 mm that is smaller than its own body OD, so stainless rows are not used.
- McMaster-Carr sells most of these with per-part STEP; this page links its category and does not copy its files. McMaster's filters list thread sizes 4-40 to 1/2-20 and M3 to M12, consistent with the range here.

## Sizes

| thread | units | hole / drill | grip range | body OD | flange OD | flange thickness | length |
|---|---|---|---|---|---|---|---|
| M3 | mm | 5.0 (PEM: 5.1 ±0.1) | 0.5 – 1.5 | 4.9 | 8.0 | 0.8 | 10.0 |
| M3 | mm | 5.0 (PEM: 5.1 ±0.1) | 2.0 – 3.5 | 4.9 | 8.0 | 0.8 | 11.5 |
| M4 | mm | 6.0 (PEM: 6.1 ±0.1) | 0.5 – 2.0 | 5.9 | 9.0 | 0.9 | 10.5 |
| M4 | mm | 6.0 (PEM: 6.1 ±0.1) | 2.0 – 3.5 | 5.9 | 9.0 | 0.9 | 12.0 |
| M5 | mm | 7.0 (PEM: 7.1 ±0.1) | 0.5 – 2.5 | 6.9 | 10.0 | 1.0 | 13.0 |
| M5 | mm | 7.0 (PEM: 7.1 ±0.1) | 2.5 – 5.0 | 6.9 | 10.0 | 1.0 | 16.5 |
| M5 | mm | 7.0 (PEM: 7.1 ±0.1) | 5.0 – 8.0 | 6.9 | 10.0 | 1.0 | 19.0 |
| M6 | mm | 9.0 (PEM: 9.1 ±0.1) | 0.5 – 3.0 | 8.9 | 12.3 | 1.3 | 15.5 |
| M6 | mm | 9.0 (PEM: 9.1 ±0.1) | 3.0 – 5.5 | 8.9 | 12.3 | 1.3 | 19.5 |
| M6 | mm | 9.0 (PEM: 9.1 ±0.1) | 5.5 – 8.0 | 8.9 | 12.3 | 1.3 | 21.0 |
| M8 | mm | 11.0 (PEM: 11.1 ±0.1) | 1.0 – 3.5 | 10.9 | 14.5 | 1.5 | 18.5 |
| M8 | mm | 11.0 (PEM: 11.1 ±0.1) | 3.5 – 6.0 | 10.9 | 14.5 | 1.5 | 21.0 |
| M8 | mm | 11.0 (PEM: 11.1 ±0.1) | 5.0 – 8.0 | 10.9 | 14.5 | 1.5 | 23.0 |
| M10 | mm | 13.0 (PEM: 13.1 ±0.1) | 1.0 – 4.0 | 12.9 | 17.0 | 1.7 | 21.5 |
| M10 | mm | 13.0 (PEM: 13.1 ±0.1) | 4.0 – 6.5 | 12.9 | 17.0 | 1.7 | 24.0 |
| M10 | mm | 13.0 (PEM: 13.1 ±0.1) | 6.5 – 9.0 | 12.9 | 17.0 | 1.7 | 27.0 |
| M12 | mm | 16.0 (PEM: 16.1 ±0.1) | 1.0 – 4.0 | 15.9 | 22.0 | 2.0 | 25.0 |
| M12 | mm | 16.0 (PEM: 16.1 ±0.1) | 3.5 – 6.0 | 15.9 | 22.0 | 2.0 | 28.0 |
| 6-32 | in (max/min) | #12 | .010 – .075 | .189/.185 | .325/.315 | .037/.027 | .453/.423 |
| 6-32 | in (max/min) | #12 | .075 – .120 | .189/.185 | .325/.315 | .037/.027 | .515/.485 |
| 6-32 | in (max/min) | #12 | .120 – .160 | .189/.185 | .325/.315 | .037/.027 | .515/.485 |
| 8-32 | in (max/min) | #2 | .010 – .075 | .221/.217 | .357/.347 | .037/.027 | .453/.423 |
| 8-32 | in (max/min) | #2 | .075 – .120 | .221/.217 | .357/.347 | .037/.027 | .515/.485 |
| 8-32 | in (max/min) | #2 | .120 – .160 | .221/.217 | .357/.347 | .037/.027 | .515/.485 |
| 10-24 and 10-32 | in (max/min) | #E | .010 – .080 | .250/.246 | .406/.396 | .043/.033 | .546/.516 |
| 10-24 and 10-32 | in (max/min) | #E | .080 – .130 | .250/.246 | .406/.396 | .043/.033 | .609/.579 |
| 10-24 and 10-32 | in (max/min) | #E | .130 – .180 | .250/.246 | .406/.396 | .043/.033 | .656/.626 |
| 1/4-20 | in (max/min) | #Q | .020 – .080 | .332/.328 | .475/.465 | .063/.053 | .640/.610 |
| 1/4-20 | in (max/min) | #Q | .080 – .140 | .332/.328 | .475/.465 | .063/.053 | .702/.672 |
| 1/4-20 | in (max/min) | #Q | .140 – .200 | .332/.328 | .475/.465 | .063/.053 | .765/.735 |
| 1/4-20 | in (max/min) | #Q | .200 – .260 | .332/.328 | .475/.465 | .063/.053 | .827/.797 |
| 5/16-18 | in (max/min) | #Z | .030 – .125 | .413/.409 | .665/.655 | .067/.057 | .765/.735 |
| 5/16-18 | in (max/min) | #Z | .125 – .200 | .413/.409 | .665/.655 | .067/.057 | .890/.860 |
| 5/16-18 | in (max/min) | #Z | .200 – .275 | .413/.409 | .665/.655 | .067/.057 | .952/.922 |
| 3/8-16 | in (max/min) | 12.5 mm | .030 – .115 | .480/.476 | .781/.771 | .093/.083 | .859/.829 |
| 3/8-16 | in (max/min) | 12.5 mm | .115 – .200 | .490/.486 | .781/.771 | .093/.083 | .953/.923 |
| 3/8-16 | in (max/min) | 12.5 mm | .200 – .285 | .490/.486 | .781/.771 | .093/.083 | 1.046/1.016 |

## Where the files are

- Westfield Fasteners (distributor): [Flat head, knurled body, open end rivet nut (metric): dimensions and tolerances, zinc plated steel and stainless tables](https://www.westfieldfasteners.co.uk/Standards/RivetNut-FlatKnurlOpen-M.html) — web — Distributor page; dimensions are facts
- PEM (Sherex): [Rivet nut hole size chart: recommended hole diameter for standard round-body rivet nuts, M3 to M12, +/-0.1 mm](https://www.pemnet.com/eu/technical/rivet-nut-hole-size-chart) — web — Publisher's page; dimensions are facts
- Unnamed maker datasheet (hosted on a Shopify CDN): [Rivet nuts (blind threaded inserts), flat head, large flange: 6-32 to 3/8-16, drill size, grip range, body length, body diameter, head diameter, head height (max / min)](https://cdn2.shopify.com/s/files/1/0056/7856/3437/files/Inslrgsmooth.pdf) — web — Maker datasheet, maker not named on the sheet; numbers only
- RS PRO (RS Components): [Flat head, round knurled body, open end rivet nut, A2 stainless: M3 to M12 (used only to show how flange OD varies by maker)](https://docs.rs-online.com/e097/A700000007117926.pdf) — web — Publisher's page; dimensions are facts
- McMaster-Carr: [Rivet nuts (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/rivnuts/) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

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

Index: https://xemstudio.com/files/hardware/rivet-nuts-flat-head/index.json

- rivet-nut-hole-gauge-m3-m12: [STEP](https://xemstudio.com/files/hardware/rivet-nuts-flat-head/rivet-nut-hole-gauge-m3-m12.step) · [STL](https://xemstudio.com/files/hardware/rivet-nuts-flat-head/rivet-nut-hole-gauge-m3-m12.stl) — hole gauge plate, 131.7 × 32.1 × 3 mm, seven holes at the PEM (Sherex) recommended rivet-nut hole diameters 5.1, 6.1, 7.1, 9.1, 11.1, 13.1, 16.1 mm (M3, M4, M5, M6, M8, M10, M12), smallest first, 8 mm between hole edges; plate thickness and spacing are Xem choices

## Questions

**What size hole for an M6 rivet nut?**

9.0 mm in Westfield's table, 9.1 mm ±0.1 mm recommended by PEM (Sherex) for a standard round-body nut.

**What hole for a 1/4-20 rivet nut?**

Drill #Q is printed on the maker datasheet used here (flat head, large flange); its decimal is not printed on that sheet.

**What is the grip range of a rivet nut?**

The sheet thickness range one nut length covers: for example M6 0.5–3.0, 3.0–5.5 and 5.5–8.0 mm in the Westfield table.

## Fits with

- [Heat-set threaded inserts, metric: M2 to M10, standard, short and Voron (CNC Kitchen sizes)](https://xemstudio.com/objects/heat-set-inserts/)
- [Heat-set threaded inserts, inch: #2-56 to 3/8-16 and G1/8 (CNC Kitchen sizes)](https://xemstudio.com/objects/heat-set-inserts-inch/)
- [Heat-set threaded inserts, ruthex RX series: M2 to M8 and #2-56 to 3/8-16](https://xemstudio.com/objects/heat-set-inserts-ruthex/)
- [Blind (pop) rivets, dome head: 3.2, 4.0, 4.8 mm and 1/8, 5/32, 3/16 in: hole size, head diameter, grip range, length](https://xemstudio.com/objects/blind-pop-rivets-dome-head/)
- [Ribbed plastic expansion anchors (wall plugs): drill size, length and screw range](https://xemstudio.com/objects/ribbed-plastic-expansion-anchors/)
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/)