Cap & Acorn Nuts vs. Hex Nuts
Comparing 2 standards across 11 specifications. 11 key differences identified.
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.
The Standard Hex Nut (standardized under ISO 4032, DIN 934, and ASME B18.2.2) is a 6-sided internal-threaded mechanical fastener. Paired with mating machine screws and structural bolts, it converts rotational tightening torque into axial clamping preload across industrial and architectural assemblies.
Specification Comparison Table
11 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard Specifications
|
DIN 1587 (High type dome) / DIN 917 (Low profile cap) / ASME B18.2.2 | ISO 4032 (Standard style 1) / DIN 934 / 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 | — |
|
Primary Applications
|
Bicycle axle hubs, motorcycle engine covers, outdoor playground structures, furniture | — |
|
Geometry
|
— | 6-sided regular hexagonal prism with internal tapped thread and double chamfered faces |
|
Nominal Height Ratio
|
— | Height ≈ 0.8× Nominal Diameter (m ≈ 0.8D) |
|
Metric Property Classes
|
— | Class 6, Class 8 (for 8.8 bolts), Class 10 (for 10.9 bolts), Class 12 (for 12.9 bolts) |
|
Imperial Strength Grades
|
— | Grade 2 (plain), Grade 5 (dot markings), Grade 8 (corner dots/notches) |
|
Jam Nut Variant
|
— | ISO 4035 / DIN 439 (Thin half-height hex nut used for locking) |