Low Cap (Acorn) Nuts are selected when an assembly calls for a low hex cap nut that closes the thread end where a high acorn nut would stand too tall. This application guide to the DIN 917 type covers concrete end-uses, the specification checklist, correct installation, and where an alternative fastener performs better. Stocked across roughly M4 to M36, they cover general to heavy-duty work.
Typical Applications for Low Cap (Acorn) Nuts
The most common settings where these are specified:
- Furniture: exposed bolt ends in low-clearance areas.
- Playground equipment: covered thread ends for safety.
- Handrails: neat finishing on fixings.
- Machinery: covers over studs near moving parts.
How to Specify Low Cap (Acorn) Nuts for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M4–M36; check the full table below for the exact dimensions of each size.
- Locking & grade: Match the strength grade to the bolt, and choose a locking style (nyloc, all-metal, serrated flange) if the joint sees vibration.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to DIN 917. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Installation & Assembly Practice
- Run the nut down by hand before applying the wrench to catch cross-threading early.
- Tighten the nut rather than the bolt head where access allows — the torque-to-preload relation is more consistent.
- For locking styles, note that nyloc inserts are single-use in critical joints and lose grip above roughly 120 °C.
Common Selection Mistakes with Low Cap (Acorn) Nuts
- Pairing a high-class bolt with a lower-class nut — the nut strips before the bolt reaches proof load; the nut class must meet or exceed the bolt class.
- Using a plain nut with a spring washer in severe vibration instead of a prevailing-torque locking nut.
- Re-using nyloc nuts in critical joints.
Where Low Cap (Acorn) Nuts Are Not the Right Choice
Not on their own — they need a matching bolt or stud — and a plain nut is not a substitute for a locking type under heavy vibration.
Custom manufacturing · Made to drawing
Need a low cap (acorn) nuts outside the standard range?
Height and across-flats are the two most often changed — a thinner nut for clearance, a larger hex for a tool that is already on the line. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
