Side-by-Side Comparison
Nuts & Threaded Inserts
Cap & Acorn Nuts vs. Threaded Inserts & Heat-Set Bushings
Comparing 2 standards across 11 specifications. 11 key differences identified.
Comparing:
Cap & Acorn Nuts
Threaded Inserts & Heat-Set Bushings
Cap and Acorn nuts (standardized under DIN 1587 and ASME B18.2.2) feature a domed, blind-ended crown that completely encloses the protruding end of a mating screw or threaded rod. They prevent snagging on clothing, protect exposed threads from corrosion and moisture, and provide a finished decorative appearance on consumer goods, bicycles, and furniture.
Threaded inserts (including brass heat-set inserts for 3D-printed thermoplastics and helical wire coils / Helicoils for soft aluminum) provide robust, reusable internal machine screw threads in materials that would otherwise strip under repeated fastener torque.
Specification Comparison Table
11 Parameters| Parameter / Spec | ||
|---|---|---|
|
Primary Applications
|
Bicycle axle hubs, motorcycle engine covers, outdoor playground structures, furniture | 3D printer enclosures, drone frames, automotive engine block head-bolt thread repairs, electronics housings |
|
Standard Specifications
|
DIN 1587 (High type dome) / DIN 917 (Low profile cap) / ASME B18.2.2 | — |
|
Dome Profile
|
Hemispherical blind cap permanently enclosing internal tapped threads | — |
|
Safety Function
|
Eliminates sharp exposed screw threads that cause lacerations or fabric snags | — |
|
Environmental Protection
|
Seals internal thread engagement from weather, road salt, and industrial grime | — |
|
Common Materials
|
A2/A4 Stainless steel, solid brass, chrome-plated steel, black oxide steel | — |
|
Insert Technologies
|
— | Brass tapered heat-set inserts, Helical wire coils (DIN 8140), Self-tapping wood inserts |
|
Heat-Set Installation
|
— | Heated with soldering iron tip at 200°C–250°C into pre-molded/printed pilot holes |
|
Retention Features
|
— | Opposing diagonal diamond knurling rings and undercuts that capture melted plastic |
|
Helicoil Material
|
— | Diamond-profile 304 stainless steel spring wire (1.0D, 1.5D, 2.0D thread engagement length) |
|
Pull-Out Strength
|
— | Up to 5× to 10× higher tensile pullout resistance than threads cut directly into polymer or wood |