Description

Eye bolts (eyebolts) are threaded bolts with a loop or eye at one end. The eye is used to anchor a cable, rope or chain. Eye bolts are rated for different types of applications and may pivot or swivel.

Load-rated eyebolts are designed for vertical lifting, but are not recommended for angular lifting. Eye bolts that are not load-rated are designed for use with tie downs and guiding wires; however, they are not suitable for lifting applications.

Types

There are four specialized types of eyebolts.

• Forged eyebolts are forged instead of formed. These one-piece fasteners that offer higher load ratings.
• Screw eyes are screws with a head shaped into a loop or eye. They are often used in lifting and rigging applications, or to guide wire or cable.
• Shoulder eyebolts have a shoulder under the eye. Typically, the shoulder is installed flush with the mounting surface.
• Thimble eyebolts are designed with an opening that acts as a thimble for wire or rope to minimize wear.
• Pivoting eyebolts are designed to pivot 180°. The base of a swiveling eyebolt is designed to swivel 360°.

Specifications

Specifications for eyebolts include:

• Maximum load capacity - The maximum load which an eyebolt can handle.
• Shank length - For fully-threaded eyebolts, shank diameter equals the thread length.
• Threaded length
• Eye inside diameter (ID)
• Eye section diameter or eye thicknes
• Total weight

Thread Sizes

Thread sizes for eyebolts are measured in English units such as inches (in) or metric units such as millimeters (mm). Measurements for inch-based eyebolts include:

• 1/4"
• 5/16"
• 3/8"
• 7/17"
• 1/2"
• 5/8"
• 3/4"
• 7/8"
• 1"
• 1 1/8"
• 1 1/4"
• 1 3/8"
• 1 1/2"
• 1 3/4"
• 2"
• 2 1/4"
• 2 1/2"
• 2 3/4"

Fasteners designated as #16, #18, #20, #24 eyebolts are also available. Designations for metric eyebolts include:

• M6
• M8
• M10
• M12
• M14
• M16
• M18
• M20
• M22
• M24
• M25
• M26
• M27
• M28
• M30
• M32
• M33
• M35
• M36
• M38
• M40
• M42
• M48
• M56
• M54

As a rule, the numbers which follow the letter “M” indicate the number of millimeters in diameter. For example, an M6 eyebolt is 6 mm in diameter. 

Material and Finish

Eyebolts differ in terms of material and finish. Plastic eyebolts and rubber eyebolts may be suitable for some applications. Metallic eyebolts can be made of materials including:

• Aluminum
• Brass
• Bronze
• Steel
• Hardened steel
• Stainless steel
• Titanium
• Proprietary alloys

In terms of finish, eyebolts are often anodized, galvanized, or plated with gold, silver, tin, or zinc. Black oxide is an eyebolt coating that causes virtually no dimensional change. Phosphate coatings provide corrosion resistance and a better surface for the adhesion of primers and paints. Eye bolts with zinc chromate finishes are also available. 

Standards

DIN 444 - Eyebolts

ASME B18.15 - Forged eyebolts

References

Image Credits:

Te-Co, Inc.