Description
Chicago Screw Sizes, Post Lengths & Specifications
The chart below lists standard Chicago screw thread sizes, part numbers, barrel post lengths, thread depths, body diameters and head dimensions. Select the required thread size and finished assembly thickness to request a production quote.
Part No |
Thread Size |
Length / L |
Thread Depth / T |
Body Dia, / D |
Head Dia, / A |
Head Hight / H |
| SHB832-14 | #8-32 | 1/4″ | 1/5″ | 1/4″ | 3/8″ | 1/8″ |
| SHB832-38 | #8-32 | 3/8″ | 1/4″ | 13/64″ | 7/16″ | 9/64″ |
| SHB832-12 | #8-32 | 1/2″ | 1/4″ | 1/4″ | 3/8″ | 1/8″ |
| SHB832-34 | #8-32 | 3/4″ | 1/2″ | 1/4″ | 3/8″ | 1/8″ |
| SHB832-10 | #8-32 | 1″ | 1/2″ | 1/4″ | 3/8″ | 1/8″ |
| SHB1032-12 | #10-32 | 1/2″ | 1/4″ | 5/16″ | 7/16″ | 9/64″ |
| SHB1032-34 | #10-32 | 3/4″ | 1/2″ | 5/16″ | 7/16″ | 9/64″ |
| SHB420-14 | #1/4-20 | 1/4″ | 3/16″ | 3/8″ | 9/16″ | 1/8″ |
| SHB420-12 | #1/4-20 | 1/2″ | 1/4″ | 3/8″ | 9/16″ | 5/32″ |
| SHB420-1932 | #1/4-20 | 19/32″ | 1/2″ | 3/8″ | 9/16″ | 5/32″ |
| SHB420-58 | #1/4-20 | 5/8″ | 1/2″ | 5/16″ | 1/2″ | 9/64″ |
| SHB420-34 | #1/4-20 | 3/4″ | 1/2″ | 3/8″ | 9/16″ | 5/32″ |
| SHB420-78 | #1/4-20 | 7/8″ | 7/8″ | 3/8″ | 9/16″ | 1/8″ |
| SHB420-1916 | #1/4-20 | 1-3/16″ | 3/4″ | 3/8″ | 9/16″ | 3/16″ |
| SHB420-10 | #1/4-20 | 1″ | 1/2″ | 3/8″ | 9/16″ | 5/32″ |
What Is a Chicago Screw?
A Chicago screw is a two-piece fastening system consisting of an internally threaded female barrel post and a matching externally threaded male screw.
The barrel post passes through the materials being joined, and the mating screw threads into the post from the opposite side. When tightened, the two heads clamp the assembly together while maintaining a clean, low-profile appearance on both sides.
Chicago screws are also commonly searched as binding posts, binding screws, screw posts, barrel nuts and screws, male and female screws or sex bolts.
Unlike rivets, Chicago screws can be removed and reinstalled for maintenance, component replacement or adjustment. Unlike conventional nuts and bolts, their wide, low-profile heads provide a cleaner finished appearance.
Available Thread Sizes & Post Lengths
Chicago screws are available from stock in standard inch thread sizes with multiple barrel post lengths. Select the post length according to the total thickness of the materials being clamped and the required thread engagement.
#8-32 Chicago Screws
- #8-32 × 1/4 in. Chicago Screw Post
- #8-32 × 3/8 in. Chicago Screw Post
- #8-32 × 1/2 in. Chicago Screw Post
- #8-32 × 3/4 in. Chicago Screw Post
- #8-32 × 1 in. Chicago Screw Post
#10-24 Chicago Screws
- #10-24 Chicago Screw Posts
- Available in multiple post lengths.
#10-32 Chicago Screws
- #10-32 × 1/2 in. Chicago Screw Post
- #10-32 × 3/4 in. Chicago Screw Post
1/4-20 Chicago Screws
- 1/4-20 × 1/4 in. Chicago Screw Post
- 1/4-20 × 1/2 in. Chicago Screw Post
- 1/4-20 × 19/32 in. Chicago Screw Post
- 1/4-20 × 5/8 in. Chicago Screw Post
- 1/4-20 × 3/4 in. Chicago Screw Post
- 1/4-20 × 7/8 in. Chicago Screw Post
- 1/4-20 × 1 in. Chicago Screw Post
- 1/4-20 × 1-3/16 in. Chicago Screw Post
5/16-18 Chicago Screws
- 5/16-18 Chicago Screw Posts
- Available in multiple post lengths.
Refer to the specification chart above for exact part numbers, post lengths, thread depths, body diameters and head dimensions.
How to Select a Chicago Screw Size
The correct Chicago screw should be selected according to:
- Total thickness of the assembled materials
- Barrel post length
- Internal thread depth
- Mating screw length
- Thread size
- Body diameter
- Mounting hole diameter
- Head diameter and available clearance
- Material and finish
- Required clamp load
The barrel post should pass through the assembly without excessive clearance. The mating screw must provide sufficient thread engagement without bottoming out inside the post.
For a custom application, provide the total material thickness, mounting hole diameter, required thread size, desired head style and finish.
Materials & Finishes
Chicago screws and binding posts are available in:
- Aluminum
- Aluminum and brass combinations
- Carbon steel
- Brass
- Stainless steel
Available finishes may include:
- Clear zinc
- Black zinc
- Nickel plating
- Brass plating
- Black oxide
- Chrome
- Decorative finishes
- Application-specific coatings
Steel provides economical strength for general industrial use. Stainless steel offers greater corrosion resistance, while aluminum reduces assembly weight. Brass is commonly selected for decorative appearance, electrical properties and corrosion resistance.
Material and finish availability varies by thread size, post length, application and production quantity.
Head & Drive Options
The standard products shown on this page feature truss heads with slotted drives.
Additional production options may include:
- Phillips drive
- Combination drive
- Six-lobe or Torx-style drive
- One-way security drive
- Flat head
- Button head
- Pan head
- Custom head diameters
- Custom head markings
Head and drive combinations should be selected according to the installation method, appearance, security and torque requirements.
How Chicago Screws Are Installed
Chicago screws require access to both sides of the assembly.
Installation procedure:
- Prepare a correctly sized through-hole.
- Insert the female barrel post through one side of the assembly.
- Insert the mating screw from the opposite side.
- Engage the screw with the internal thread of the post.
- Tighten both components until the materials are securely clamped.
- Confirm that the screw has sufficient thread engagement without bottoming out.
A compatible thread-locking compound may be considered when additional resistance to loosening is required. Compatibility should be verified with the selected material and finish.
Typical Chicago Screw Applications
Chicago screws are used where a clean, reusable and removable through-panel connection is required.
Typical applications include:
- Furniture manufacturing
- Architectural hardware
- Commercial partitions
- Display fixtures
- Signage
- Electrical enclosures
- Equipment panels
- Fitness equipment
- Railings and guards
- Leather goods
- Binders, menus and sample books
- Helmets and protective equipment
- Industrial machinery
- OEM product assemblies
Chicago Screws, Binding Posts & Sex Bolts
These terms often describe the same general two-piece fastening concept, but usage varies by industry.
Chicago screws and binding posts are common terms in furniture, bookbinding, leather goods, displays and architectural applications.
Barrel nuts and screws describe the internally threaded female barrel and its matching screw.
Sex bolts are commonly used in industrial and engineering specifications for a male screw and female barrel fastener set.
Using these names throughout the page helps purchasing professionals and engineers from different industries identify the same general product.
Factory-Direct Supply & Custom Production
Imperial Rivets & Fasteners supplies factory-direct Chicago screws, binding posts and mating screws to OEMs, manufacturers, distributors and industrial assembly operations.
Available thread sizes include:
- #8-32
- #10-24
- #10-32
- 1/4-20
- 5/16-18
Multiple post lengths and material options are available. We can also support production requirements involving custom:
- Thread sizes
- Barrel post lengths
- Body diameters
- Head styles
- Drive styles
- Materials
- Finishes
- Mating screws
- Packaging requirements
Select a standard part from the specification chart above and add it to your RFQ. For custom production, provide a drawing or specify the thread size, post length, body diameter, head dimensions, material, finish and estimated annual quantity.
Questions or Custom Requirements?
Contact our sales team at sales@imperialrivet.com or (630) 964-0208.
