Pole Cross Arms | Wood Cross Arms | Fiberglass Cross Arms

Crossarms, often called bullhorns, serve as horizontal support structures that secure light fixtures, power lines, and communication equipment to utility poles. After 17 years in commercial lighting and utility infrastructure, we've seen how quality crossarms form the backbone of reliable electrical networks across diverse environments.

What Are Utility Pole Crossarms?

LED Lighting Supply's utility pole crossarms function as horizontal mounting beams that attach perpendicular to utility poles. Beyond simple support, they establish crucial clearance distances between electrical conductors to prevent dangerous arcing. Most installations require crossarms ranging from 4 feet to 12 feet in length, depending on voltage requirements and conductor spacing. Primary distribution lines typically need wider spacing than secondary service drops, making crossarm selection critical for both safety and code compliance.

Types of LED Lighting Supply Crossarm Materials

Wood Crossarms

Southern yellow pine crossarms dominate utility installations because they balance performance with affordability. We typically recommend pressure-treated wood crossarms rated for Class 1 or Class 2 loading, which handle most residential and light commercial applications. The pressure treatment process forces preservatives deep into the wood fiber, creating a barrier against moisture, insects, and fungal decay that can extend service life to 25-40 years. Standard dimensions like 3¼ inches x 4¼ inches provide adequate strength for typical secondary voltage applications while remaining cost-effective for large utility deployments.

Fiberglass Crossarms

Fiberglass construction delivers exceptional longevity in challenging environments where wood struggles. Salt air, industrial chemicals, and extreme temperature cycling that would degrade wood have minimal impact on fiberglass crossarms. We've installed fiberglass units in coastal regions that show virtually no degradation after decades of service. The material's non-conductive properties also provide an additional safety margin during maintenance operations. With service lives exceeding 80 years, fiberglass crossarms justify their higher initial cost through reduced replacement frequency and virtually eliminated maintenance requirements.

Pole Cross Arm Benefits

Choosing appropriate crossarms impacts both immediate installation success and long-term system reliability.

• Enhanced Durability: Premium materials withstand decades of weather exposure while maintaining structural integrity under ice loading and wind stress
• Improved Safety: Engineered spacing prevents conductor contact during wind sway and thermal expansion cycles
• Cost-Effective: Extended service life reduces replacement labor and material costs over the system lifecycle
• Reliability: Robust construction minimizes service interruptions from crossarm failure during storms
• Regulatory Compliance: All units meet ANSI C136.20 and relevant electrical safety standards

Selecting the Proper Crossarm Solution

Material selection depends on several project-specific factors. Coastal installations benefit from fiberglass's corrosion resistance, while inland utilities often choose pressure-treated wood for its proven track record. Load calculations determine whether standard single crossarms suffice or if double configurations are necessary. We generally recommend fiberglass for 69kV and above applications, while wood crossarms work well for distribution voltages up to 35kV.

Common Crossarm Configurations

Different electrical configurations require specific crossarm arrangements:

• Standard Single Crossarm: Handles typical three-phase distribution with 6-8 foot lengths most common
• Double Crossarm: Stacked configuration supports transmission circuits requiring 12-15 foot conductor spacing
• Braced Crossarms: Diagonal bracing handles heavy conductor loads and ice accumulation in northern climates
• Custom Configurations: Specialized angles accommodate unique right-of-way constraints or equipment requirements

Crossarm length selection follows conductor voltage and phase spacing requirements. Distribution circuits typically use 8-foot crossarms for standard spacing, while transmission applications may require 12-foot or longer configurations to maintain adequate clearances.

Installation Best Practices

Successful crossarm installation starts with proper hardware selection and mounting techniques. Galvanized bolts rated for the expected load prevent premature failure, while stainless steel hardware provides maximum corrosion resistance in aggressive environments. Pre-drilling prevents wood splitting and ensures accurate pin hole alignment. Double-nutted connections with lock washers maintain tight joints despite thermal cycling. Diagonal braces should be installed at 45-degree angles for optimal load distribution and structural stability.

Ready to Enhance Your Utility Infrastructure?

Speak with a Product Specialist to discuss your project requirements. Whether upgrading existing infrastructure or planning new installations, our team will help you select the optimal solution for your utility pole system. Request a free pole quote here.

Pole Cross Arms | Wood Cross Arms | Fiberglass Cross Arms Frequently Asked Questions

What Are Crossarms on Utility Poles and What Do They Do?

Crossarms are horizontal support structures that mount perpendicular to utility poles to secure light fixtures, power lines, and communication equipment. They establish crucial clearance distances between electrical conductors to prevent dangerous arcing and ensure code compliance. Most installations require crossarms ranging from 4 feet to 12 feet in length, with primary distribution lines needing wider spacing than secondary service drops.

What's the Difference Between Wood and Fiberglass Crossarms?

Wood crossarms use pressure-treated southern yellow pine with service lives of 25-40 years and work well for distribution voltages up to 35kV. Fiberglass crossarms offer superior longevity with service lives exceeding 80 years and perform better in coastal or chemically aggressive environments. We recommend fiberglass for 69kV and above applications, while pressure-treated wood provides cost-effective performance for most distribution circuits.

How Long Do Utility Pole Crossarms Last?

Pressure-treated wood crossarms typically last 25-40 years depending on environmental conditions and load factors. Fiberglass crossarms exceed 80 years of service life with minimal degradation from weather, chemicals, or temperature cycling. Coastal installations and industrial environments with chemical exposure favor fiberglass construction for maximum longevity.

What Size Crossarm Do I Need for My Application?

Crossarm sizing depends on voltage requirements and conductor spacing needs. Standard three-phase distribution circuits typically use 6-8 foot single crossarms, while transmission applications require 12-15 foot double crossarm configurations. Standard wood dimensions of 3¼ inches x 4¼ inches handle most residential and light commercial applications rated for Class 1 or Class 2 loading.

Are Crossarms Required to Meet Specific Safety Standards?

All quality crossarms must meet ANSI C136.20 specifications and relevant electrical safety codes for conductor spacing and load capacity. Proper crossarm selection ensures adequate clearance distances during wind sway and thermal expansion cycles. Double-nutted galvanized connections with lock washers maintain structural integrity under ice loading and temperature cycling.

When Should I Use Double Crossarms Instead of Single?

Double crossarm configurations become necessary for transmission circuits requiring 12-15 foot conductor spacing or heavy conductor loads exceeding single crossarm capacity. Stacked crossarms also provide better stability in areas with significant ice accumulation or extreme wind conditions. Load calculations determine whether standard single crossarms suffice or if double configurations are required for safety.

What Installation Hardware Do Crossarms Require?

Proper crossarm installation requires galvanized bolts rated for expected loads, with stainless steel hardware providing maximum corrosion resistance in aggressive environments. Pre-drilling prevents wood splitting and ensures accurate pin hole alignment. Diagonal braces should be installed at 45-degree angles for optimal load distribution when additional structural support is needed.

How Do Environmental Conditions Affect Crossarm Selection?

Coastal installations benefit from fiberglass crossarms' superior corrosion resistance against salt air exposure. Industrial environments with chemical exposure also favor fiberglass construction over wood. Inland utilities often choose pressure-treated wood for proven performance and cost-effectiveness in standard weather conditions.

Why Choose LED Lighting Supply for Crossarm Solutions?

We bring 15+ years of commercial and industrial infrastructure experience with 25,000+ completed projects to every crossarm specification. Our consultative approach goes beyond product sales to provide technical guidance on material selection, load calculations, and configuration requirements. We help contractors and utilities select optimal crossarm solutions based on voltage requirements, environmental conditions, and long-term reliability needs rather than simply fulfilling product orders.

What's the Cost Difference Between Wood and Fiberglass Crossarms?

While fiberglass crossarms carry higher upfront costs than pressure-treated wood, their 80+ year service life versus wood's 25-40 years reduces total lifecycle expenses. The extended service life eliminates multiple replacement cycles and associated labor costs over decades of operation. Reduced maintenance requirements and virtually no degradation in challenging environments justify fiberglass investment for long-term infrastructure planning.

Can Crossarms Handle Ice Loading and Wind Stress?

Quality crossarms engineered for regional conditions withstand ice accumulation and wind loading when properly sized and installed. Braced crossarm configurations with diagonal support handle heavy conductor loads and extreme weather events in northern climates. Double-nutted connections with proper torque specifications maintain structural integrity despite thermal cycling and mechanical stress from wind and ice.