# PEM self-clinching standoffs (SO, SOS, SOA and blind BSO): hole size, sheet thickness, edge distance, M3–M5 and #4-40 to #10-32 + hole gauges

> What hole size and edge distance for a PEM SO self-clinching standoff, and how thin a sheet can it go in?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: PEM's SO-series data sheet (sodata.pdf) read as text, thread by thread; two hole gauges as files
- Page: https://xemstudio.com/objects/pem-self-clinching-standoffs-so-bso/ · JSON: https://xemstudio.com/api/geometry?object=pem-self-clinching-standoffs-so-bso · Plain text: https://xemstudio.com/objects/pem-self-clinching-standoffs-so-bso/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 |
|---|---|---|
| 32.8 | 15.1 | 3.0 |

**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

- Types: SO (steel, sheet hardness HRB 80 / HB 150 or less), SOS (stainless, HRB 70 / HB 125 or less), SOA (aluminium, HRB 50 / HB 82 or less, aluminium only) and SO4 (installs in stainless sheet to HRB 88 / HB 183); BSO, BSOS, BSOA and BSO4 are the blind (threaded one end, closed at the other) versions with the same dimensions (hardness limits as printed in the data sheet). Unthreaded SO standoffs, SOSG, DSO and TSO types exist and are not tabulated.
- Columns as the data sheet prints them: sheet thickness (read as the minimum sheet the standoff is sized for: .040 / .050 in and 1 / 1.27 mm), minimum hole size B (+.003 / −.000 in; the data sheet lists a minimum only, no separate maximum), the bore diameter in the sheet, the dimension H, the minimum distance from hole centreline to edge D (±.010 in) and the length codes (1/32 in for inch; mm for metric). The PDF text extraction scrambled the columns, so values were assigned by matching them to the metric ones; verify the assignment against PEM's drawing before relying on it. The data sheet also lists a minimum F dimension (.156, .187, .250, .375 in; 3.2, 4, 5, 6.5, 9.5 mm) for the blind type without saying which thread each belongs to; it is not shown.
- Files are two hole gauges (smallest first; 3 mm plate, 4 mm gaps and margin are Xem choices). The standoff itself is PEM's part (its CAD is on PEM's product pages, not rehosted). Plain threaded standoffs that are not clinched: threaded-standoffs-metric.

## 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 |
|---|---|---|---|---|
| hole in sheet | M3 Ø4.22, M3.5 5.41, M4 / M5 7.14 mm min; #4-40 .166, #6-32 .213, #8-32 / #10-32 .281 in | PEM SO / BSO standoff pressed into the sheet | press | clinch-hole-gauge-* |

## Sizes

| type | thread / code | sheet thickness | min hole size B | bore in sheet | H | min dist hole C/L to edge D | length codes |
|---|---|---|---|---|---|---|---|
| SO / SOS / SOA / SO4 (inch) | #4-40 (.112-40), codes 440 | .040 | .166 | .165 | H .187 | .23 | 4–24 (.125–.750 in) |
| SO / SOS / SOA / SO4 (inch) | 6440 | .040 | .213 | .212 | H .250 | .27 | 4–24 |
| SO / SOS / SOA / SO4 (inch) | #6-32 (.138-32), code 632 | .040 | .213 | .212 | H .250 | .27 | 4–34 (.125–1.062 in) |
| SO / SOS / SOA / SO4 (inch) | 8632 | .050 | .281 | .280 | H .312 | .31 | 4–34 |
| SO / SOS / SOA / SO4 (inch) | #8-32 (.164-32), code 832 | .050 | .281 | .280 | H .312 | .31 | 4–34 |
| SO / SOS / SOA / SO4 (inch) | #10-32 (.190-32), code 032 | .050 | .281 | .280 | H .312 | .31 | 4–34 |
| SO / SOS / SOA / SO4 (metric) | M3 x 0.5 | 1 | 4.22 | 4.2 | H 4.8 | 6 | 3, 4, 6, 8, 10, 12, 14, 16, 18 |
| SO / SOS / SOA / SO4 (metric) | 3.5M3 | 1 | 5.41 | 5.39 | H 6.4 | 6.8 | 3–18 |
| SO / SOS / SOA / SO4 (metric) | M3.5 x 0.6 | 1 | 5.41 | 5.39 | H 6.4 | 6.8 | 3–25 |
| SO / SOS / SOA / SO4 (metric) | M4 x 0.7 | 1.27 | 7.14 | 7.12 | H 7.9 | 8 | 3–25 |
| SO / SOS / SOA / SO4 (metric) | M5 x 0.8 | 1.27 | 7.14 | 7.12 | H 7.9 | 8 | 3–25 |
| BSO / BSOS / BSOA / BSO4 (inch, blind) | #4-40 (.112-40), codes 440 | .040 | .166 | .165 | H .187 | .23 | 10–34 (1/32 in codes) |
| BSO / BSOS / BSOA / BSO4 (inch, blind) | 6440 | .040 | .213 | .212 | H .250 | .27 | 10–34 (1/32 in codes) |
| BSO / BSOS / BSOA / BSO4 (inch, blind) | #6-32 (.138-32), code 632 | .040 | .213 | .212 | H .250 | .27 | 10–34 (1/32 in codes) |
| BSO / BSOS / BSOA / BSO4 (inch, blind) | 8632 | .050 | .281 | .280 | H .312 | .31 | 10–34 (1/32 in codes) |
| BSO / BSOS / BSOA / BSO4 (inch, blind) | #8-32 (.164-32), code 832 | .050 | .281 | .280 | H .312 | .31 | 10–34 (1/32 in codes) |
| BSO / BSOS / BSOA / BSO4 (inch, blind) | #10-32 (.190-32), code 032 | .050 | .281 | .280 | H .312 | .31 | 10–34 (1/32 in codes) |
| BSO (metric, blind) | M3 x 0.5 | 1 | 4.22 | 4.2 | H 4.8 | 6 | 6–25 |
| BSO (metric, blind) | 3.5M3 | 1 | 5.41 | 5.39 | H 6.4 | 6.8 | 6–25 |
| BSO (metric, blind) | M3.5 x 0.6 | 1 | 5.41 | 5.39 | H 6.4 | 6.8 | 6–25 |
| BSO (metric, blind) | M4 x 0.7 | 1.27 | 7.14 | 7.12 | H 7.9 | 8 | 6–25 |
| BSO (metric, blind) | M5 x 0.8 | 1.27 | 7.14 | 7.12 | H 7.9 | 8 | 6–25 |

## Where the files are

- PennEngineering (PEM): [Threaded standoffs types SO, SOS, SOA, SO4 and BSO, BSOS, BSOA, BSO4 (data sheet sodata.pdf): hole size, sheet thickness, distance to edge, lengths](https://www.pemnet.com/wp-content/uploads/sites/9/2022/06/sodata.pdf) — web — Manufacturer data sheet; dimensions are facts; CAD is PEM's, not hosted
- McMaster-Carr: [Press-fit (self-clinching) nuts (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/press-fit-nuts/thread-size~m6-2/) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Free STEP/STL (2 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/pem-self-clinching-standoffs-so-bso/index.json

- clinch-hole-gauge-pem-standoffs-metric: [STEP](https://xemstudio.com/files/hardware/pem-self-clinching-standoffs-so-bso/clinch-hole-gauge-pem-standoffs-metric.step) · [STL](https://xemstudio.com/files/hardware/pem-self-clinching-standoffs-so-bso/clinch-hole-gauge-pem-standoffs-metric.stl) — hole gauge plate, 32.8 × 15.1 × 3 mm, three holes at PEM's minimum hole size for SO / BSO standoffs: Ø4.22 (M3), 5.41 (M3.5), 7.14 (M4, M5) mm; plate thickness and spacing are Xem choices
- clinch-hole-gauge-pem-standoffs-inch: [STEP](https://xemstudio.com/files/hardware/pem-self-clinching-standoffs-so-bso/clinch-hole-gauge-pem-standoffs-inch.step) · [STL](https://xemstudio.com/files/hardware/pem-self-clinching-standoffs-so-bso/clinch-hole-gauge-pem-standoffs-inch.stl) — hole gauge plate, 32.8 × 15.1 × 3 mm, three holes at PEM's hole size for SO / BSO standoffs: .166 (#4-40), .213 (#6-32 and 6440), .281 (#8-32 and #10-32) in; plate thickness and spacing are Xem choices

## Questions

**What hole for an M3 PEM SO standoff?**

4.22 mm minimum hole size, edge distance 6 mm, in 1 mm sheet (data sheet SO / BSO metric table).

**What hole for a #6-32 PEM SO standoff?**

.213 in minimum (code 632 and 6440), D = .27 in, sheet .040 in.

## Fits with

- [PEM self-clinching nuts (S, CLS, CLSS): hole size, minimum edge distance, nut diameter and height, M2–M12 and #2-56 to 3/8-24 + hole gauges](https://xemstudio.com/objects/pem-self-clinching-nuts-s-cls/)
- [PEM self-clinching studs (FH, FHS, FHLS): hole size, minimum sheet thickness, edge distance, #2-56 to #8-32 and M3–M4 + hole gauges](https://xemstudio.com/objects/pem-self-clinching-studs-fh/)
- [Threaded standoffs, M2.5 and M3 (hex and round)](https://xemstudio.com/objects/threaded-standoffs-metric/)
- [Rivet nuts (blind threaded inserts), flat head: hole size, grip range, body and flange dimensions, M3–M12 and #6-32 to 3/8-16](https://xemstudio.com/objects/rivet-nuts-flat-head/)
- [Heat-set threaded inserts, metric: M2 to M10, standard, short and Voron (CNC Kitchen sizes)](https://xemstudio.com/objects/heat-set-inserts/)