Cap Nut Spec Table
A domed nut that covers the bolt end for a clean appearance and safety, concealing exposed threads.
Practical Notes
- Match bolt length precisely. Too-long bolts hit the internal cap bottom, causing incomplete tightening.
- Closed structure — cannot be used on through-bolts. Calculate bolt protrusion length in advance.
Selection Guide
Covers exposed bolt ends for safety and aesthetics. Dome cap prevents scratches and injuries. Used where safety regulations apply — playgrounds, furniture, food machinery. Closed structure means bolt length must be precise; too-long bolts won't seat properly.
Cap NutDINJISCap Nut
6 sizesThe dimensions below are identical across DIN 1587 · JIS B 1183.
| Nominal | d | P | H (Height) | B (Wrench) | Other |
|---|---|---|---|---|---|
| M4 | 4 | 0.7 | 8 | 7 | - |
| M5 | 5 | 0.8 | 9.5 | 8 | - |
| M6 | 6 | 1 | 11.5 | 10 | - |
| M8 | 8 | 1.25 | 15 | 13 | - |
| M10 | 10 | 1.5 | 18 | 17 | - |
| M12 | 12 | 1.75 | 22 | 19 | - |
Key Features
- Dome-shaped cap completely covers bolt end, preventing thread exposure
- DIN 1587 (high type); chrome plating or stainless steel for aesthetic finish
- Prevents scratches/injuries from protruding bolt ends; meets safety regulations
Key Applications
Exposed furniture joints, playground safety bolts, food machinery hygiene, handrails, medical device exteriors
STEP File Downloads
Free 3D CAD models (STEP AP214). Built to real standard dimensions; threads are simplified (plain shank) per free-library convention.
FAQ
How to check internal depth of cap nuts?
Internal effective thread depth varies by specification. If bolt protrusion exceeds cap depth, tightening fails — check spec table for internal depth.