Eye Bolts and Nuts
RIGGING SUPPLY YOU CAN DEPEND ON
Professional Eye Bolts and Nuts - Marine Hardware
Eye bolts and nuts are essential fastening hardware featuring a threaded bolt with a formed eye or loop at one end, used to create secure attachment points for rigging, lifting, anchoring, and securing loads. From marine deck hardware and boat rigging to industrial lifting and general-purpose applications, quality eye bolts provide reliable connection points that can handle significant loads while resisting corrosion in harsh environments. US Rigging offers professional-grade eye bolts and nuts in stainless steel construction, engineered for strength, durability, and dependable performance in demanding marine and rigging applications.
Types of Eye Bolts
Regular Eye Bolts
Standard eye bolts with a formed eye perpendicular to the bolt shank. Designed for straight vertical pulls only, not angular loads.
Key Features:
- Formed eye perpendicular to shank
- Designed for vertical loads only
- Most economical eye bolt option
- Various thread sizes and eye sizes
- Suitable for light to medium duty applications
- Must be loaded in line with shank
Critical Warning: Regular eye bolts are designed for straight vertical pulls only. Angular loading dramatically reduces capacity and can cause failure. Use shoulder eye bolts for angular loads.
Shoulder Eye Bolts
Eye bolts with a shoulder that seats against the mounting surface, allowing safe angular loading up to 45 degrees from vertical.
Key Features:
- Shoulder seats against mounting surface
- Rated for angular loads up to 45°
- Higher capacity than regular eye bolts
- More versatile for rigging applications
- Professional-grade construction
- Essential for side-loading applications
Load Capacity by Angle:
- 0° (Vertical): 100% of rated capacity
- 45° from vertical: Approximately 30% of rated capacity
- 90° (Horizontal): Not recommended, use alternative hardware
Swivel Eye Bolts
Eye bolts with a rotating eye that can pivot, allowing the load to align naturally and reducing side loading stress.
Key Features:
- Rotating eye allows load alignment
- Reduces side loading stress
- Good for applications with changing load directions
- Higher cost than fixed eye bolts
- Ideal for marine and rigging applications
Pad Eyes
Flat plate with an eye, designed to be through-bolted to surfaces. Common in marine applications for deck hardware.
Key Features:
- Flat plate distributes load over larger area
- Through-bolt mounting for maximum strength
- Excellent for deck and bulkhead mounting
- Various sizes and configurations
- Professional marine hardware
Materials & Construction
Stainless Steel Eye Bolts
The preferred choice for marine applications due to excellent corrosion resistance.
- 316 Stainless Steel: Best corrosion resistance, ideal for saltwater environments
- 304 Stainless Steel: Good corrosion resistance, suitable for freshwater and less corrosive environments
- 18-8 Stainless Steel: Economical option with good corrosion resistance
Other Materials
- Galvanized Steel: Economical, good for non-marine applications
- Zinc-Plated Steel: Basic corrosion protection, indoor use
- Plain Steel: No corrosion protection, dry indoor use only
Common Applications
Marine Applications
- Deck hardware attachment points
- Rigging connections
- Anchor and mooring points
- Sail rigging
- Equipment securing
Lifting & Rigging
- Overhead lifting points
- Hoist attachments
- Load securing
- Rigging connections
- Material handling
Industrial Applications
- Equipment mounting
- Cable management
- Safety line anchors
- Machinery attachment
- General fastening
General Purpose
- Tie-down points
- Rope and chain attachment
- Swing and playground equipment
- Garage and workshop organization
- DIY projects
Proper Installation
Installation Guidelines
- Proper Hole Size: Drill hole to correct size for bolt threads
- Thread Engagement: Ensure adequate thread engagement (minimum 1.5x bolt diameter)
- Backing Plate: Use backing plate or washer to distribute load
- Tighten Properly: Tighten nut securely but don't over-torque
- Lock Nut: Use lock nut or thread locker to prevent loosening
- Eye Orientation: Orient eye in direction of load for shoulder eye bolts
- Surface Preparation: Ensure mounting surface is clean and flat
- Sealant: Use marine sealant for deck penetrations to prevent water intrusion
Critical Installation Warnings
- Adequate Strength: Mounting surface must be strong enough to handle loads
- Through-Bolt When Possible: Through-bolting is stronger than threading into material
- No Welding: Never weld eye bolts - heat treatment is destroyed
- Proper Orientation: Eye must be oriented correctly for load direction
- Regular Inspection: Check tightness and condition regularly
Safe Use Guidelines
Safety Considerations
- Load Direction: Regular eye bolts for vertical loads only, shoulder eye bolts for angular loads
- Working Load Limits: Never exceed rated capacity
- Angular Loading: Capacity decreases significantly with angle - consult load charts
- Inspect Before Use: Check for damage, corrosion, or loosening
- Proper Hardware: Use appropriate shackles or carabiners in the eye
- No Shock Loading: Avoid sudden impacts or dynamic loads
- Corrosion Check: Inspect regularly in marine environments
- Replacement: Replace if damaged, corroded, or questionable
Choosing the Right Eye Bolt
Key Considerations
- Load Direction: Vertical only = regular eye bolt; angular loads = shoulder eye bolt
- Load Capacity: Ensure working load limit exceeds maximum expected loads
- Material: 316 stainless for saltwater, 304 for freshwater, galvanized for non-marine
- Thread Size: Match to mounting hole and load requirements
- Eye Size: Large enough for your shackles or hardware
- Environment: Corrosive environments require stainless steel
- Application: Marine, lifting, industrial, or general purpose
- Quality: Use rated, certified eye bolts for critical applications
Inspection & Maintenance
Inspection Guidelines
- Visual Inspection: Check for cracks, deformation, or damage
- Corrosion: Look for rust, pitting, or corrosion
- Tightness: Verify nut is tight and hasn't loosened
- Eye Condition: Check eye for wear, cracks, or deformation
- Thread Condition: Inspect threads for damage or stripping
- Mounting Surface: Check that mounting surface is sound
Retirement Criteria - Replace Eye Bolt If:
- Cracks, deformation, or bending visible
- Excessive corrosion or pitting present
- Eye shows wear, cracks, or deformation
- Threads are damaged or stripped
- Eye bolt has been overloaded
- Nut cannot be tightened properly
- Any doubt exists about integrity
Maintenance
- Freshwater Rinse: Rinse with freshwater after saltwater exposure
- Tighten Regularly: Check and tighten nuts periodically
- Lubrication: Apply anti-seize compound to threads during installation
- Corrosion Treatment: Address corrosion early
- Documentation: Track installation dates for critical applications
Frequently Asked Questions
What's the difference between regular and shoulder eye bolts?
Regular eye bolts are designed for straight vertical pulls only and will fail if loaded at an angle. Shoulder eye bolts have a shoulder that seats against the mounting surface, allowing safe angular loading up to 45 degrees from vertical. For any application where side loading might occur, always use shoulder eye bolts. The capacity of shoulder eye bolts decreases significantly with angle - at 45°, capacity is only about 30% of vertical rating.
Can I use eye bolts for overhead lifting?
Yes, but only if they are properly rated and installed for lifting applications. Use shoulder eye bolts for overhead lifting where angular loads may occur. Ensure the eye bolt is rated for the load, properly installed with adequate thread engagement, and inspected regularly. Follow OSHA and ASME B30.26 guidelines for rigging hardware. Never use hardware store eye bolts for critical lifting - use certified lifting eye bolts.
Should I use 304 or 316 stainless steel?
For saltwater marine applications, use 316 stainless steel for superior corrosion resistance. The molybdenum in 316 stainless provides much better protection against saltwater corrosion. 304 stainless is adequate for freshwater environments and less corrosive conditions. For critical marine hardware, the extra cost of 316 stainless is worth the investment in longevity and safety.
How much thread engagement do I need?
Minimum thread engagement should be 1.5 times the bolt diameter for full strength. For example, a 1/2" eye bolt needs at least 3/4" of thread engagement. More is better - aim for full thread engagement through the mounting material when possible. Through-bolting with a nut on the back side is stronger than threading into material.
Can I weld an eye bolt to a surface?
No, never weld eye bolts. Welding destroys the heat treatment and dramatically reduces strength, potentially causing catastrophic failure under load. Eye bolts must be properly bolted or threaded into place. If you need a welded attachment point, use a welded pad eye or lifting lug specifically designed for welding.
Professional Eye Bolts and Nuts from US Rigging
US Rigging is a manufacturer and master distributor of climbing ropes, fall protection equipment, and industrial rigging equipment located in Santa Ana, California. With over 40 years of experience, we offer professional-grade eye bolts and nuts in stainless steel construction, engineered for strength, corrosion resistance, and dependable performance in demanding marine and rigging applications.
Our eye bolt collection includes regular eye bolts, shoulder eye bolts, swivel eye bolts, and pad eyes in various sizes and materials including 316 and 304 stainless steel. Whether you need secure attachment points for marine deck hardware, overhead lifting points for rigging operations, or general-purpose fastening hardware, we have the quality eye bolts and nuts that meet marine industry standards for reliable performance in harsh environments.
Browse our eye bolt selection and contact our knowledgeable team for expert guidance. Trust reliable eye bolts and nuts for your marine hardware needs from US Rigging.