---
title: "Knock-down hardware"
description: "Threaded inserts, cam locks, dowels and shelf pins — what each cuts, what it demands of the panel, and which to reach for."
url: https://kaicad.barpom.xyz/docs/catalogue/knock-down-hardware
schema: "0.1"
source: packages/catalogue/data/fixtures/knock-down.yaml
---

# Knock-down hardware

Hardware other than [bed bolts](/docs/catalogue/bed-bolts) for pieces that come apart — plus
the two entries that are not knock-down at all but live in the same file: the glued dowel and
the shelf pin.

These are what let a design satisfy `requirements.knock_down` without glue.

## Threaded inserts

The one to reach for in sheet goods. A wood screw into the edge of MDF or plywood holds
badly — every sheet material in the catalogue rates `low` or `poor` there. An insert converts
a poor screw joint into a good machine-screw joint.

| Id | Insert | Machine screw | Drive |
| --- | --- | --- | --- |
| `fixtures.threaded_insert.m6` | 10 Ø × 13, M6 | M6 × 40 | Hex 4 |
| `fixtures.threaded_insert.m8` | 13 Ø × 15, M8 | M8 × 50 | Hex 5 |

**Through part** | **Receiving part**

| Id | Clearance | Counterbore | Insert bore |
| --- | --- | --- | --- |
| `m6` | 6.5, through | 11 × 6 | 8.5 × 15 deep |
| `m8` | 8.5, through | 14 × 8 | 11 × 17 deep |

| Id | Min edge | Min end | Min engagement | Min spacing |
| --- | --- | --- | --- | --- |
| `m6` | 15 | 20 | 13 | 32 |
| `m8` | 20 | 26 | 15 | 40 |

End grain is `allow` — like a bed bolt, the load goes into steel rather than into wood.

**The insert goes in before assembly and stays in.** Only the machine screw comes out when the
piece is taken apart, which is what makes this joint survive being assembled and disassembled
repeatedly where a wood screw into the same hole would not.

## Cam locks

Flat-pack hardware: a cam buried in one panel, a dowel bolt threaded into the other, and a
quarter turn pulls them together.

| Id | Cam | Bolt | Drive |
| --- | --- | --- | --- |
| `fixtures.cam_lock.15` | 15 Ø × 12.5 | 7 Ø × 34 | Pozi 2 |

| Through part | Receiving part |
| --- | --- |
| 15 mm bore, 12.5 deep · 8 mm cross bore at 9.5 depth, 24 long | 5 mm bore, 12 deep |

| Min edge | Min end | Min engagement | Min spacing | Min panel thickness |
| --- | --- | --- | --- | --- |
| 12 | 24 | 11 | 64 | **15** |

**Needs at least 15 mm of panel to bury the cam**, which is why it does not belong in 12 mm
ply. That minimum is enforced, and the finding names it.

End grain is `warn`: the dowel bolt threads into wood, so it is a real concern here in a way
it is not for an insert.

## Dowels

| Id | | |
| --- | --- | --- |
| `fixtures.dowel.8x40` | 8 × 40 fluted beech | Both holes 8 Ø × 21 deep |

| Min edge | Min end | Min engagement | Min spacing |
| --- | --- | --- | --- |
| 16 | 24 | 19 | 32 |

Both holes are **1 mm deeper than half the dowel** so glue has somewhere to go and the joint
actually closes. Two 20 mm holes for a 40 mm dowel is how you end up with a joint that will
not seat.

**A doweled joint is glued, so it is not knock-down.** If the design declares
`requirements.knock_down: true` and a dowel sits on the disassembly path, that is a finding.
Dowels are here for alignment and for glued joinery, not for a piece that comes apart.

## Shelf pins

| Id | | |
| --- | --- | --- |
| `fixtures.shelf_pin.5` | 5 mm pin, 16 long | 5 Ø × 10 deep, receiving part only |

| Min edge | Min end | Min engagement | Min spacing |
| --- | --- | --- | --- |
| 10 | 20 | 9 | 32 |

Adjustable shelving is drilled on the **32 mm system**, so a spacing that is a multiple of 32
keeps the whole drilling plan on one jig setting. Write it that way:

```yaml
pattern: { along: length, count: 12, spacing: 32, from: 200 }
```

End grain is `warn`. The pin carries the shelf in shear, so the hole wants face grain around
it.

## Which to use

| Situation | Reach for |
| --- | --- |
| Rail into the end of a post, must come apart | [Bed bolt](/docs/catalogue/bed-bolts) |
| Panel edge in sheet goods, must come apart | Threaded insert |
| Flat-pack carcass, 15 mm panels or thicker | Cam lock |
| Alignment in a glued joint | Dowel |
| Adjustable shelf | Shelf pin |
| Everything else, glued or not structural | [Wood screw](/docs/catalogue/wood-screws) |

## Procurement

| Id | Pack sizes | Unit cost |
| --- | --- | --- |
| `threaded_insert.m6` | 10 · 25 · 50 | 0.55 |
| `threaded_insert.m8` | 10 · 25 | 0.75 |
| `cam_lock.15` | 10 · 20 | 0.35 |
| `dowel.8x40` | 50 · 100 | 0.06 |
| `shelf_pin.5` | 20 · 100 | 0.09 |