Description
Chicago Screw Extension Sizes & Specifications
The chart below lists standard Chicago screw extension part numbers, body lengths, extension lengths, body diameters, thread depths and thread sizes. Select an extension that matches the thread size and construction of the existing binding post assembly.
Specifications
These extension screws are designed to increase the effective length of binding posts and Chicago screws, making them suitable for thicker or multi-layer material applications.
Standard Sizes and Dimensions
Part No. |
Body Length (L) |
Extension Length (E) |
Body Diameter (D) |
Thread Depth (T) |
Thread Size |
| AEB832-14 | 1/4″ | 0.2″ | 0.2″ | 0.187″ | 8-32 |
| AEB832-12 | 1/2″ | 0.2″ | 0.2″ | 0.375″ | 8-32 |
| AEB832-34 | 3/4″ | 0.2″ | 0.2″ | 0.375″ | 8-32 |
| AEB832-1 | 1″ | 0.2″ | 0.2″ | 0.375″ | 8-32 |
Available in body lengths from 1/4″ to 1″, with standard 8-32 thread size.
What Is a Chicago Screw Extension?
A Chicago screw extension is a threaded connector used to increase the effective length or binding capacity of an existing Chicago screw, binding post or screw post assembly.
One end of the extension engages with the existing binding post, while the other end accepts the matching screw or another compatible extension. This allows the assembly to accommodate thicker panels, additional layers or expanding materials without replacing the complete fastener system.
These products are also commonly called:
- Screw post extensions
- Binding post extensions
- Chicago screw post extensions
- Binding screw extensions
- Threaded post extensions
- Barrel nut extensions
- Extension posts
- Interscrew extensions
Extension screws provide a practical solution for adjustable assemblies, frequently updated materials and applications where the required finished thickness may change.
Standard #8-32 Sizes
Standard #8-32 Chicago screw extensions are available in the following body lengths:
- #8-32 × 1/4 in. Chicago Screw Extension
- #8-32 × 1/2 in. Chicago Screw Extension
- #8-32 × 3/4 in. Chicago Screw Extension
- #8-32 × 1 in. Chicago Screw Extension
Available Thread Sizes
Chicago screw and binding post extensions are available in the following UNC thread sizes:
- #8-32 Chicago Screw Post Extensions
- 10-24 Chicago Screw Post Extensions
- 1/4-20 Chicago Screw Post Extensions
- 5/16-18 Chicago Screw Post Extensions
Standard stocked dimensions may vary by thread size. Custom body lengths, thread depths, diameters and thread sizes are available for production requirements.
How Binding Post Extensions Work
A binding post extension adds usable length between the original female post and the mating screw.
The extension threads into the existing binding post, creating an additional internally threaded section for the original screw. Multiple compatible extensions may be combined when additional binding capacity is required, provided there is sufficient thread engagement throughout the assembly.
The total finished assembly length depends on:
- Original binding post length
- Extension body length
- Thread engagement between components
- Mating screw length
- Total thickness of the materials being fastened
For reliable assembly, all connecting components must have compatible thread sizes and sufficient thread engagement.
How to Select the Correct Extension
First, measure the total thickness of the materials being assembled. Compare this measurement with the usable length of the existing Chicago screw or binding post.
The extension should provide enough additional length to accommodate the material thickness while maintaining secure engagement with the original post and mating screw.
Before ordering, confirm:
- Existing binding post thread size
- Existing post length
- Required additional length
- Total assembled material thickness
- Extension body diameter
- Available thread engagement
- Material and finish
- Required order quantity
Do not select an extension based only on overall length. Thread size, thread depth and compatibility with the original binding post must also be confirmed.
Materials & Finishes
Chicago screw post extensions are available in:
- Aluminum
- Brass-finish aluminum
- Zinc-plated steel
- Black zinc-plated steel
- Chrome-plated steel
- Brass
- Stainless steel
Aluminum provides a lightweight and economical option for binding, display and decorative applications.
Zinc-plated steel provides strength and general corrosion protection for industrial and commercial assemblies.
Chrome-plated steel provides a clean finished appearance for visible furniture, display and architectural applications.
Brass offers corrosion resistance and a decorative appearance, while stainless steel is available for applications requiring greater strength, durability or corrosion resistance.
Material, finish and dimensional availability may vary by thread size and production quantity.
Advantages of Chicago Screw Post Extensions
Threaded post extensions provide several advantages:
- Increase the effective length of existing binding posts
- Accommodate thicker or multi-layer materials
- Eliminate the need to replace the complete fastener assembly
- Allow assemblies to be adjusted as material thickness changes
- Provide a clean and reusable fastening system
- Install without specialized machinery
- Available in multiple thread sizes and materials
- Standard and custom lengths available
- Compatible with many Chicago screw and binding post systems
Installation Instructions
Confirm that the extension and existing binding post have matching thread sizes.
Thread the male end of the extension into the existing female binding post and tighten until securely seated. Insert the assembly through the aligned mounting holes, then install the matching screw into the female end of the extension.
Tighten the components using the appropriate driver while preventing the opposite side from rotating.
For longer assemblies using multiple extensions, confirm that every connection has sufficient thread engagement. Avoid overtightening, especially when fastening paper, leather, plastic, laminate or other compressible materials.
Typical Applications
Chicago screw and binding post extensions are commonly used where additional fastening length or adjustable binding capacity is required.
Typical applications include:
- Sample books and swatch books
- Product catalogs
- Menus and price books
- Architectural and engineering drawings
- Document and portfolio binding
- Leather goods and belts
- Packaging and presentation kits
- Retail displays
- Signage and panel assemblies
- Furniture and hardware assembly
- Decorative fastening
- Multi-layer industrial assemblies
- OEM products requiring adjustable post lengths
Factory-Direct Supply & Custom Options
Imperial Rivets & Fasteners supplies factory-direct Chicago screw extensions, binding post extensions and screw post extensions for commercial and OEM applications.
Standard #8-32 extensions are available in body lengths from 1/4 in. through 1 in. Additional 10-24, 1/4-20 and 5/16-18 thread sizes may be supplied according to application requirements.
Custom body lengths, diameters, thread depths, materials, finishes and thread configurations can be manufactured according to your drawing, sample or assembly requirements.
Select a standard extension from the specification chart and add it to your RFQ. If the required size is not listed, send us the existing post dimensions, required additional length, thread size, material, finish and estimated quantity for evaluation.
Questions, Samples or Custom Requirements?
Contact our sales team at sales@imperialrivet.com or (630) 964-0208.
