CW-USB: Single Upset Spool Bolt HDG

A single upset spool bolt is a specialized pole line fastener designed to support a spool insulator in a side-of-pole installation.

The bolt includes a forged upset section near the insulator end. This formed section helps locate and retain the spool insulator assembly while providing the required spacing between the insulator and pole.

You can commonly use single upset spool bolts in:

• Overhead electrical distribution lines
• Secondary conductor systems
• Neutral conductor support
• Wood utility pole construction
• Spool insulator mounting
• Pole line maintenance projects

Because the upset section is forged as part of the bolt rather than attached as a separate welded component, the bolt maintains an integral load-bearing structure.

Key Features of the Single Upset Spool Bolt

Forged Single-Upset Structure

The forged upset section forms part of the bolt itself.

As a result, you do not rely on a separately welded collar to position the insulator.

This construction also gives the product its characteristic single upset design.

Designed for Spool Insulators

You use the bolt together with a compatible spool insulator for side-of-pole installation.

The assembly helps support neutral or secondary conductors while maintaining separation between the conductor system and pole.

Hot-Dip Galvanized Finish

The hot-dip galvanized coating protects the steel surface against outdoor corrosion.

Therefore, the bolt is suitable for utility pole applications exposed to rain, humidity, and changing weather conditions.

If your project specifies a particular galvanizing standard or coating thickness, send the requirement with your RFQ so we can confirm it before production.

Complete Fastening Hardware

The standard assembly includes the required fastening components for field installation.

Depending on the ordered configuration, the assembly can include:

• 5/8″ round washer
• 5/8″ regular square nuts
• 5/8″ concave square locknut
• Cotter pin

Please confirm the exact hardware configuration when requesting a quotation.

Multiple Shank Lengths

Standard Hbcrownwealth models cover several common utility pole requirements:

• 9″ shank
• 10″ shank
• 12″ shank
• 14″ shank

You can also provide your drawing or sample when your project requires another dimension.

Single Upset Spool Bolt Specifications

Mechanical Data

Tensile Strength: 13,550 lbs
Recommended Torque: 15 ft-lb
Thread Diameter: 5/8″
Thread Length: 4″ or 6″ depending on model
Surface Finish: Hot-Dip Galvanized

Technical data should always be confirmed against the final drawing or project specification before bulk production.

Where Is a Single Upset Spool Bolt Used?

The main application is side-of-pole spool insulator installation.

In overhead distribution systems, spool insulators can support secondary or neutral conductors in a horizontal position.

The single upset spool bolt passes through or supports the spool insulator assembly and connects it securely to the utility pole.

Typical users include:

• Electric utilities
• Distribution network contractors
• Utility pole installers
• Pole line hardware distributors
• Electrical wholesalers
• Infrastructure contractors

Because installation dimensions vary between networks, you should select the correct shank length according to the pole and insulator arrangement.

Single Upset vs. Double Upset Spool Bolt

Single and double upset spool bolts perform a similar basic job. However, their forged upset structures and resulting installation geometry differ.

The double upset spool bolt generally provides greater clearance from the pole than the single upset version.

Therefore, you should choose between the two according to the required conductor position, spool insulator arrangement, and project drawing.

If you are not sure which model your project requires, send us the existing bolt dimensions, pole drawing, or sample.

How Do You Choose the Correct Single Upset Spool Bolt?

Before ordering, check several dimensions and installation requirements.

1. Confirm the Thread Diameter

The standard CW-USB series uses a 5/8″ thread.

If your project specifies another diameter, provide the technical drawing before quotation.

2. Select the Shank Length

Choose the shank length according to your utility pole and installation arrangement.

Hbcrownwealth standard options include:

9″, 10″, 12″ and 14″

Longer shanks also use a longer threaded section.

3. Check the Overall Length

Do not confuse shank length with overall product length.

For example, the CW-USB10 uses a 10″ shank while the overall bolt length is approximately 14-1/2″.

Therefore, always confirm which dimension your drawing specifies.

4. Confirm the Spool Insulator

Check the dimensions of the spool insulator that you will use with the bolt.

The insulator, pin area, upset section, cotter pin, and fastening hardware must work together correctly.

5. Verify the Required Clearance

If your conductor arrangement requires greater spacing between the spool insulator and pole, compare the single upset design with a double upset spool bolt.

Do not choose the bolt only according to shank length.

6. Send the Required Utility Standard

Utility tenders may specify:

• Material
• Mechanical strength
• Thread requirements
• Galvanizing standard
• Coating thickness
• Dimensions
• Inspection method
• Packaging and marking

Send these requirements before production so the manufacturer can confirm compliance with your specific project.

Single Upset Spool Bolt vs. Standard Machine Bolt

Although both products are threaded fasteners, they serve different functions.

Therefore, a standard machine bolt should not automatically replace a specified upset spool bolt.

Always follow the pole line or utility drawing.

Why Use a Hot-Dip Galvanized Spool Bolt?

Utility pole hardware remains outdoors for long periods.

Without adequate surface protection, moisture and environmental exposure can cause steel components to corrode.

Hot-dip galvanizing creates a protective zinc coating over the steel surface.

As a result, an HDG single upset spool bolt provides improved corrosion resistance for outdoor pole line applications.

However, galvanizing requirements vary between utilities and countries.

If your tender calls for a particular ASTM, ANSI, BS, EN, or other specification, send the complete requirement instead of assuming that all HDG products follow the same standard.

Quality Control for Single Upset Spool Bolts

Consistent dimensions are especially important for pole line hardware.

During production and inspection, key control points can include:

• Steel raw material
• Bolt diameter
• Shank length
• Overall length
• Thread length
• Thread dimensions
• Forged upset position
• Cotter pin hole position
• Washer and nut dimensions
• Galvanized surface
• Mechanical performance
• Final assembly
• Packaging and labeling

For project orders, you can also provide inspection criteria or an approved sample before mass production.

Why Choose Hbcrownwealth?

Hbcrownwealth is a manufacturer and wholesale supplier of pole line and overhead telecom hardware.

When you source single upset spool bolts from Hbcrownwealth, you can discuss your drawing, application, quantity, packaging, and project specifications directly with the manufacturer.

We support:

• Standard and customized sizes
• Bulk manufacturing
• OEM and ODM requirements
• Hot-dip galvanized pole line hardware
• Drawing and sample development
• Customized packaging
• Export orders
• Mixed product shipments

If you are sourcing hardware for a utility tender or long-term distribution program, send your complete specification so our team can review the dimensions and production requirements before quotation.

Frequently Asked Questions

What is a single upset spool bolt?

A single upset spool bolt is a utility pole fastener designed to support a spool insulator in a side-of-pole installation. It includes a forged upset structure near the insulator end.

What is a single upset spool bolt used for?

You mainly use it with spool insulators to support neutral and secondary conductors on utility poles.

What sizes are available?

Hbcrownwealth standard models include 5/8″ × 9″, 5/8″ × 10″, 5/8″ × 12″ and 5/8″ × 14″.

What is the difference between single and double upset spool bolts?

The main difference is the forged upset configuration. Double upset designs generally create greater pole clearance, while single upset bolts suit standard side-of-pole spool insulator arrangements.

Are the collars welded?

No. The upset structure is forged rather than formed from a separately welded collar.

What finish does the spool bolt use?

The CW-USB models use a hot-dip galvanized finish for outdoor corrosion protection.

What thread diameter does the bolt use?

The standard CW-USB series uses a 5/8″ thread.

What comes with the spool bolt?

Depending on the ordered configuration, the assembly can include square nuts, a concave square locknut, round washer, and cotter pin.

Can Hbcrownwealth manufacture custom spool bolts?

Yes. You can send your drawing, sample, dimensions, mechanical requirements, surface finish, packaging, and quantity for OEM or ODM production.

Can I buy single and double upset spool bolts together?

Yes. You can combine different spool bolt models and other pole line hardware in a bulk or mixed shipment.