# Neodymium ring magnets (R-06-02-02 to R-40-23-06, 90 x 64 x 5), countersunk and pot magnets: OD, ID, thickness, c/sink size + ring STEP/STL

> What are the standard sizes of neodymium ring magnets (OD, ID, height) and of countersunk and pot magnets, and what is the countersink size?

- Category: Hardware › Magnets & seals
- Kind: Standard part
- Basis: supermagnete ring magnet pages (specification tables), first4magnets listings and product pages, K&J Magnetics listing names; the countersink geometry is not defined by any of them
- Page: https://xemstudio.com/objects/neodymium-ring-pot-and-countersunk-magnets/ · JSON: https://xemstudio.com/api/geometry?object=neodymium-ring-pot-and-countersunk-magnets · Plain text: https://xemstudio.com/objects/neodymium-ring-pot-and-countersunk-magnets/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/)

**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

- Ring magnets: the maker's product pages (supermagnete) give OD, ID and height directly; the sizes are in mm and non-round values are real (R-19-09-06 is 19.1 / 9.5 / 6.4, from an inch part; R-27-16-05 is 26.75 mm OD, the page text calls it 27). Rings are magnetised through the height (axial) unless the article says otherwise (diametral rings exist, K&J's R6036DIA for one, not read). Tolerance on a supermagnete magnet is +/-0.1 mm; nickel-copper-nickel plating; grade and pull are only noted where the page read printed them. The two first4magnets rings (20 x 10 x 5, 90 x 64 x 5, N42) are sized from their product titles in search results only.
- Countersunk and pot magnets: first4magnets prints each as 'diameter x thickness x N mm c/sink' (plus the grade and the pull). The page does not say what N is: its F4MA25 product page calls N the 'countersunk hole' and recommends a 5 mm c/s screw for the 5 mm figure, but does not say whether it is the through-hole, the countersink head diameter or its depth, and gives no countersink angle. K&J Magnetics names countersunk rings by size only (1/4 x 1/8 in, 3/8 x 1/8 in, 1/2 x 1/8 in, 5/8 x 1/8 in, N42 / N52) on its category pages; the countersink dimensions are on per-part pages that were not readable here. For that reason no countersunk or pot magnet is drawn: the shape (countersink diameter, angle, steel cup) is not defined by the sources. A pot magnet is a magnet sunk into a steel cup; the 'diameter' and 'thickness' are the outer sizes of the cup, and F4MA25 is magnetised only on the countersunk face, 26 kg pull from the page.
- Pull force values are the makers' test values (flush on thick mild steel), not design loads; they scale with grade and steel thickness. First4magnets prints some figures with the page's own inconsistencies (3/16 in vs 5 mm for F4MA25, 0.0004 in for +/-0.1 mm); mm values are used here. Where several makers give the same nominal size, the grade and pull differ by maker.
- Files: 12 plain rings (OD x ID x height from the table), the 10 supermagnete rings and the 2 first4magnets rings. Nominal size only: no plating thickness, no chamfer, no magnetisation arrow. Existing pages cover plain disc magnets (neodymium-disc-magnets) and a block magnet (neodymium-block-magnets).
- Left out: arc and segment magnets, ferrite and samarium-cobalt rings, K&J and supermagnete pot magnets (not read), larger countersunk blocks and channel magnets that first4magnets lists, grade tables (N35 to N52) and temperature ratings.

## 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 |
|---|---|---|---|---|
| outer diameter | Ø6 / 8 / 10 / 15 / 19.1 / 20 / 26.75 / 40 / 90 mm (per ring file) | a pocket of the same nominal diameter in your part, magnet held by press fit or glue (magnet tolerance +/-0.1 mm) | press | ring-magnet-* |
| inner diameter | Ø2 / 4 / 4.2 / 6 / 9.5 / 10 / 16 / 23 / 64 mm (per ring file) | a pin or screw shank of the same nominal diameter through the ring, or an empty hole | slide | ring-magnet-* |
| height | 2 / 5 / 5 / 6 / 6.4 / 10 / 15 mm (per ring file) | pocket depth equal to the height for a flush magnet face | designed | ring-magnet-* |

## Sizes

| part | OD / diameter, mm | ID / 'c/sink' size as printed, mm | height / thickness, mm | magnetisation | grade | pull as printed | notes |
|---|---|---|---|---|---|---|---|
| ring R-06-02-02-N (supermagnete) | 6 | 2 | 2 | axial | N45 | approx. 760 g | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-08-02-06-N (supermagnete) | 8 | 2 | 6 | axial | N50 | approx. 2.4 kg | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-10-04-05-N (supermagnete) | 10 | 4 | 5 | axial | — | approx. 2.5 kg | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-10-04-10-N (supermagnete) | 10 | 4 | 10 | axial | — | approx. 3.1 kg | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-10-04-15-N (supermagnete) | 10 | 4 | 15 | axial | — | approx. 3.3 kg | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-15-06-06-N (supermagnete) | 15 | 6 | 6 | axial | — | — | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-19-09-06-N (supermagnete) | 19.1 | 9.5 | 6.4 | axial | — | — | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-20-04-05-N (supermagnete) | 20 | 4.2 | 5 | axial | — | — | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-27-16-05-N (supermagnete) | 26.75 | 16 | 5 | axial | N42 | approx. 11 kg | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring R-40-23-06-N (supermagnete) | 40 | 23 | 6 | axial | N42 | approx. 21 kg | ring, nickel-plated NdFeB, +/-0.1 mm (stated for the ones read) |
| ring P3842 (first4magnets) | 20 | 10 | 5 | — | N42 | 3.2 kg | ring (size from the product title) |
| ring 19283 (first4magnets) | 90 | 64 | 5 | — | N42 | 163 kg | ring (size from the product title) |
| countersunk disc F102NS (first4magnets) | 10 | c/sink 3 (see notes) | 2 | — | Nd | 1.2 kg | countersunk disc |
| countersunk disc F301NS (first4magnets) | 10 | c/sink 3.2 (see notes) | 5 | — | Nd | 2 kg | countersunk disc |
| countersunk disc F124NS (first4magnets) | 12 | c/sink 4.2 (see notes) | 4 | — | Nd | 2.5 kg | countersunk disc |
| countersunk disc F338NS (first4magnets) | 15 | c/sink 4.2 (see notes) | 2 | — | Nd | 1.7 kg | countersunk disc |
| countersunk disc F317NS (first4magnets) | 15 | c/sink 4.2 (see notes) | 7.5 | — | Nd | 5.7 kg | countersunk disc |
| countersunk disc F406NS (first4magnets) | 20 | c/sink 3.6 (see notes) | 3 | — | N42 | 4.5 kg | countersunk disc |
| countersunk disc F315NS (first4magnets) | 20 | c/sink 5.2 (see notes) | 4 | — | Nd | 6.7 kg | countersunk disc |
| countersunk disc F205NS (first4magnets) | 20 | c/sink 6 (see notes) | 5 | — | N35H | 7.1 kg | countersunk disc |
| countersunk disc F314NS (first4magnets) | 20 | c/sink 5.2 (see notes) | 10 | — | Nd | 11 kg | countersunk disc |
| countersunk disc F313NS (first4magnets) | 25 | c/sink 6 (see notes) | 5 | — | Nd | 11.2 kg | countersunk disc |
| countersunk cylinder F5030NS (first4magnets) | 50 | c/sink 6 (see notes) | 30 | — | N42 | 86.9 kg | countersunk cylinder |
| countersunk pot magnet NPA12 (first4magnets) | 12 | c/sink 3 (see notes) | 4.5 | — | N42 | 3.9 kg | countersunk pot magnet |
| countersunk pot magnet F4MA16 (first4magnets) | 16 | c/sink 3 (see notes) | 5 | — | N42 | 9.6 kg | countersunk pot magnet |
| countersunk pot magnet F4MA20 (first4magnets) | 20 | c/sink 4 (see notes) | 7 | — | N42 | 13.2 kg | countersunk pot magnet |
| countersunk pot magnet F4MA25 (first4magnets) | 25 | c/sink 5 (see notes) | 8 | — | N42 | 26 kg | countersunk pot magnet |
| countersunk pot magnet F4MA32 (first4magnets) | 32 | c/sink 5.5 (see notes) | 8 | — | N42 | 44 kg | countersunk pot magnet |
| countersunk pot magnet F4MA40 (first4magnets) | 40 | c/sink 6 (see notes) | 7.5 | — | N42 | 64 kg | countersunk pot magnet |
| countersunk pot magnet F4MA48 (first4magnets) | 48 | c/sink 8.5 (see notes) | 11.5 | — | N42 | 90 kg | countersunk pot magnet |

## Where the files are

- supermagnete: [Ring magnet R-06-02-02-N (6 / 2 / 2 mm) with its neighbours R-08-02-06, R-10-04-05](https://www.supermagnete.de/eng/ring-magnets-neodymium/ring-magnet-6mm-2mm-2mm_R-06-02-02-N) — web — Publisher's page; dimensions are facts
- supermagnete: [Ring magnet R-08-02-06-N (8 / 2 / 6 mm) with R-10-04-10, R-10-04-15](https://www.supermagnete.de/eng/ring-magnets-neodymium/ring-magnet-8mm-2mm-6mm_R-08-02-06-N) — web — Publisher's page; dimensions are facts
- supermagnete: [Ring magnet R-40-23-06-N (40 / 23 / 6 mm) with R-15-06-06, R-19-09-06, R-20-04-05](https://www.supermagnete.de/eng/ring-magnets-neodymium/ring-magnet-40mm-23mm-6mm_R-40-23-06-N) — web — Publisher's page; dimensions are facts
- supermagnete: [Ring magnet R-27-16-05-N (26.75 / 16 / 5 mm)](https://supermagnete.nl/eng/ring-magnets-neodymium/ring-magnet-26.75mm-16mm-5mm_R-27-16-05-N) — web — Publisher's page; dimensions are facts
- first4magnets: [Countersunk magnets and pot magnets: product names with diameter x thickness x 'c/sink' size and pull (24 per page, pages 1 to 3)](https://www.first4magnets.com/countersunk) — web — Publisher's page; dimensions are facts
- first4magnets: [F4MA25: 25 mm x 8 mm N42 countersunk pot magnet, 5 mm c/s screw, +/-0.1 mm, 26 kg pull](https://www.first4magnets.com/us/product/25mm-dia-x-8mm-thick-x-5mm-c-sink-n42-neodymium-pot-magnet-26kg-pull-20514) — web — Publisher's page; dimensions are facts
- first4magnets: [Ring magnets: 20 x 10 x 5 mm N42 (P3842, 3.2 kg) and 90 x 64 x 5 mm N42 (19283, 163 kg), as named in the listing titles](https://www.first4magnets.com/product/90mm-od-x-64mm-id-x-5mm-thick-n42-neodymium-magnet-163kg-pull-19283) — web — Publisher's page; dimensions are facts
- K&J Magnetics: [Countersunk ring magnets (R422CS 1/4 x 1/8 in, R622CS, R822CS, RA22CS, N42 / N52): names and pull only; countersink dimensions are on per-part pages not read](https://www.kjmagnetics.com/products/countersunk-magnets) — web — Publisher's page; dimensions are facts

## Free STEP/STL (12 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/index.json

- ring-magnet-6x2x2: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-6x2x2.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-6x2x2.stl) — ring magnet R-06-02-02-N: OD 6 mm, ID 2 mm, height 2 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-8x2x6: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-8x2x6.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-8x2x6.stl) — ring magnet R-08-02-06-N: OD 8 mm, ID 2 mm, height 6 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-10x4x5: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-10x4x5.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-10x4x5.stl) — ring magnet R-10-04-05-N: OD 10 mm, ID 4 mm, height 5 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-10x4x10: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-10x4x10.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-10x4x10.stl) — ring magnet R-10-04-10-N: OD 10 mm, ID 4 mm, height 10 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-10x4x15: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-10x4x15.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-10x4x15.stl) — ring magnet R-10-04-15-N: OD 10 mm, ID 4 mm, height 15 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-15x6x6: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-15x6x6.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-15x6x6.stl) — ring magnet R-15-06-06-N: OD 15 mm, ID 6 mm, height 6 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-19p1x9p5x6p4: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-19p1x9p5x6p4.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-19p1x9p5x6p4.stl) — ring magnet R-19-09-06-N: OD 19.1 mm, ID 9.5 mm, height 6.4 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-20x4p2x5: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-20x4p2x5.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-20x4p2x5.stl) — ring magnet R-20-04-05-N: OD 20 mm, ID 4.2 mm, height 5 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-26p75x16x5: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-26p75x16x5.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-26p75x16x5.stl) — ring magnet R-27-16-05-N: OD 26.75 mm, ID 16 mm, height 5 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-40x23x6: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-40x23x6.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-40x23x6.stl) — ring magnet R-40-23-06-N: OD 40 mm, ID 23 mm, height 6 mm, a plain ring (magnetised axially, no plating thickness, no chamfer); nominal sizes, the maker's tolerance is +/-0.1 mm
- ring-magnet-20x10x5: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-20x10x5.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-20x10x5.stl) — ring magnet 20 x 10 x 5 mm (first4magnets listing title): a plain ring; nominal sizes, no chamfer or plating
- ring-magnet-90x64x5: [STEP](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-90x64x5.step) · [STL](https://xemstudio.com/files/hardware/neodymium-ring-pot-and-countersunk-magnets/ring-magnet-90x64x5.stl) — ring magnet 90 x 64 x 5 mm (first4magnets listing title): a plain ring; nominal sizes, no chamfer or plating

## Questions

**What size is the common 10 x 4 x 5 mm ring magnet?**

OD 10 mm, ID 4 mm, height 5 mm: supermagnete R-10-04-05-N, about 2.5 kg pull; there are also 10 / 4 / 10 and 10 / 4 / 15 versions.

**What does '25mm dia x 8mm thick x 5mm c/sink' mean?**

A 25 mm pot magnet, 8 mm thick, with a countersunk hole for a 5 mm c/s screw (first4magnets F4MA25, 26 kg pull). The page does not say whether 5 is the through hole or the head diameter.

**Do you give the countersink angle?**

No. None of the sources read states the countersink angle or head diameter, so there is no CAD for countersunk or pot magnets.

**How much clearance does a ring magnet need?**

The magnet is +/-0.1 mm (supermagnete). Apply your own process allowance on a press fit pocket; the files are drawn at the nominal size.

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