Description
Security Torx Chicago Screw Sizes & Specifications
The charts below list available security-pin Torx Chicago screw and binding post thread sizes, barrel lengths, mating screw lengths and dimensional specifications. Standard Torx styles without a security pin are also available.
Six-Lobe (Torx) Female Post Specifications
|
THREAD SIZE (UNC) |
Length / L ±0.01 |
Thread Depth / L1 ±0.02 |
Body Dia /D ±0.005 |
Head Dia / A ±0.008 |
Head Height / H ±0.011 |
| UNC 10-24 | 1/2″ | 0.377″ | 0.245″ | 0.425″ | 0.125″ |
| UNC 10-24 | 5/8″ | 0.5″ | 0.245″ | 0.425″ | 0.125″ |
| UNC 10-24 | 3/4″ | 0.62″ | 0.245″ | 0.425″ | 0.125″ |
Six-Lobe (Torx) Male Screw Specifications
|
THREAD SIZE (UNC) |
Length / L ±0.01 |
Shoulder / L1 ±0.008 |
Body Dia /D ±0.004 |
Head Dia / A ±0.008 |
Head Height / H ±0.008 |
| UNC 10-24 | 1/2″ | 0.13″ | 0.236″ | 0.425″ | 0.125″ |
| UNC 10-24 | 5/8″ | 0.248″ | 0.236″ | 0.425″ | 0.125″ |
| UNC 10-24 | 3/4″ | 0.248″ | 0.236″ | 0.425″ | 0.125″ |
| UNC 10-24 | 15/16″ | 0.248″ | 0.236″ | 0.425″ | 0.125″ |
| UNC 10-24 | 1-1/16″ | 0.248″ | 0.236″ | 0.425″ | 0.125″ |
| UNC 10-24 | 1-3/16″ | 0.248″ | 0.236″ | 0.425″ | 0.125″ |
| UNC 10-24 | 1-5/16″ | 0.248″ | 0.236″ | 0.425″ | 0.125″ |
| UNC 10-24 | 1-3/8″ | 0.248″ | 0.236″ | 0.425″ | 0.125″ |
What Are Six-Lobe (Torx) Chicago Screws?
A six-lobe Torx Chicago screw is a two-piece threaded fastener consisting of an internally threaded female barrel and a matching male screw. The two components pass through the materials being assembled and tighten together to create a strong, reusable connection.
These fasteners are also commonly known as:
- Torx Chicago screws
- Security Torx binding posts
- Torx barrel nuts and screws
- Six-lobe binding screws
- Screw posts
- Sex bolts
- Male and female screws
The six-lobe drive provides positive driver engagement, efficient torque transfer and reduced cam-out during installation. This makes Torx binding posts suitable for OEM production, architectural hardware and commercial assemblies requiring secure fastening and a clean finished appearance.
Security Pin and Standard Torx Styles
Our six-lobe Chicago screws are available in two drive configurations:
- Torx With Security Pin: A tamper-resistant six-lobe drive with a center pin. Installation and removal require a matching security Torx bit with a center opening.
- Torx Without Pin: A standard six-lobe drive that provides efficient torque transfer, reduced cam-out and convenient production installation.
Both drive styles are available as matching male screws and female barrel nuts. The security-pin style is recommended for public-access, institutional and high-traffic installations where unauthorized removal must be discouraged.
Available Thread Sizes
Six-lobe Torx Chicago screws and binding posts are available in the following UNC thread sizes:
- #8-32 Torx Chicago Screws and Binding Posts
- 10-24 Torx Chicago Screws and Binding Posts
- 1/4-20 Torx Chicago Screws and Binding Posts
- 5/16-18 Torx Chicago Screws and Binding Posts
Drive style, barrel length, mating screw length, material and finish availability may vary by thread size.
In-Stock 10-24 Sizes
10-24 Female Barrel Nut Lengths
- 10-24 × 1/2 in.
- 10-24 × 5/8 in.
10-24 Mating Screw Lengths
- 10-24 × 3/4 in.
- 10-24 × 15/16 in.
- 10-24 × 1-1/16 in.
- 10-24 × 1-3/16 in.
- 10-24 × 1-5/16 in.
- 10-24 × 1-3/8 in.
Additional #8-32, 1/4-20 and 5/16-18 sizes are also available. Refer to the specification charts above for exact head diameter, barrel diameter, overall length and thread dimensions.
Materials & Finishes
Six-lobe Torx Chicago screws and binding posts are available in:
- Stainless steel
- Zinc-plated steel
- Chrome-plated steel
Stainless steel provides corrosion resistance and a clean finished appearance for architectural and exterior applications. Zinc-plated steel offers strength and economical performance for general commercial and industrial assemblies. Chrome-plated steel is suitable for visible hardware where appearance is important.
Additional materials, platings and finishes may be available for OEM and volume production requirements.
Advantages of Security-Pin Torx Binding Posts
Security-pin Torx Chicago screws provide several advantages for commercial and OEM applications:
- Tamper-resistant drive with center security pin
- Requires a matching security Torx driver
- Helps discourage unauthorized removal
- Efficient torque transfer during installation
- Reduced driver slippage and cam-out
- Strong and reusable two-piece connection
- Clean finished appearance on both sides
- No welding or permanent riveting required
- Suitable for production and field installation
- Custom barrel and screw lengths available
For applications that do not require tamper resistance, the same fasteners are also available with a standard Torx drive without the center pin.
How to Select the Correct Size
Select the thread size, female barrel length and mating screw length according to the total thickness of the materials being assembled.
The female barrel should pass through the mounting holes while providing sufficient internal thread engagement for the mating screw. The screw should engage securely without bottoming out inside the barrel before the materials are properly clamped.
When requesting a quote, provide:
- Required thread size
- Total material thickness
- Female barrel length
- Mating screw length
- Security pin or standard Torx drive
- Material and finish
- Estimated order quantity
Our sales team can help evaluate the correct barrel and screw combination for your assembly.
How to Install Torx Chicago Screws
Insert the female barrel nut through the aligned mounting holes. Thread the matching male screw into the barrel from the opposite side, then tighten both components using the correct Torx driver.
Security-pin styles require a compatible tamper-resistant Torx bit with a center opening. Standard Torx styles without a pin can be installed using a regular Torx driver of the correct size.
Avoid overtightening, particularly when assembling plastic, composite, wood or other compressible materials.
Typical Applications
Security-pin Torx Chicago screws and binding posts are commonly used in commercial assemblies where tamper resistance, strength and a finished appearance are required.
Typical applications include:
- Restroom partitions
- Architectural panels
- Door and access-control hardware
- Public facilities
- Commercial furniture
- Display and fixture systems
- Signage and wayfinding systems
- Outdoor and recreational equipment
- Transportation interiors
- Equipment panels and enclosures
- Security-sensitive assemblies
- OEM production assemblies
Standard Torx styles without a pin are also available for furniture, equipment and industrial applications where efficient installation is more important than tamper resistance.
Factory-Direct Supply & Custom Options
Imperial Rivets & Fasteners supplies factory-direct security-pin Torx Chicago screws, six-lobe binding posts and barrel nuts for OEM, architectural and commercial applications.
Standard sizes are stocked for fast shipment from our U.S. warehouse. Additional thread sizes, longer barrel lengths, matching screw lengths, materials, finishes and standard Torx styles without a pin may be supplied according to production requirements.
Custom Torx barrel nuts and screws can be manufactured according to your drawings, samples or application specifications.
Select an available size from the specification chart and add it to your RFQ. If the required size is not listed, send us the thread size, barrel length, screw length, material, finish, drive style and estimated quantity for evaluation.
Questions, Samples or Custom Requirements?
Contact our sales team at sales@imperialrivet.com or (630) 964-0208.
