Types of Eye Bolts
Eye bolts have a threaded shank with a round loop on one end. This eye-shaped loop is ideal for a variety of lifting hardware attachments and uses. They are typically used to secure cables, straps, wires or chains to other objects Eye bolts are made of various materials; the most common being carbon, stainless and alloy steel. There are also different types of eye bolts, depending on the application they are being used for.
Eye Bolt Grades & Markings
Eye bolts are available in several different grades based on the mechanical and chemical properties of the material, and the intended application of the eye bolt.
According to ASME B30.26 - Rigging Hardware, each eye bolt shall be marked to show: 1. Name or trademark of manufacturer, 2. Size or rated load and 3. Grade for alloy eye bolts. This specification applies to shouldered eye bolts, non-shouldered eye bolts, forged eye bolts and nut eye bolts intended for use in critical or safety-related applications. ASME B30.26 does not apply to turned (bent) eye bolts.
ASTM A489 Lifting Eye Bolts
ASTM A489 Type 1 Lifting Eye Bolts are forged, carbon steel threaded eye bolts intended for use with tapped holes that have been engineered as a lifting point.
ASTM A489 Shoulder Lifting Eye Bolts
ASTM A489 Type 2 Shoulder Lifting Eye Bolts are forged, carbon steel threaded eye bolts intended for use with tapped holes that have been engineered as a lifting point. When equipped with a shoulder, these eye bolts can be used with angular loads up to 45°.
DIN 580 Metric Shoulder Lifting Eye Bolts
DIN 580 Metric Shoulder Lifting Eye Bolts are forged, steel (C15E+Aluminum) threaded eye bolts intended for use with tapped holes that have been engineered as a lifting point. When equipped with a shoulder, these eye bolts can be used with angular loads up to 45°. (M14 & M22 are not included in DIN 580 specifications.)
Forged Eye Bolts with Nuts
Drop Forged Eye Bolts with Nuts are heat treated steel eye bolts with a hot dip galvanized finish. The hot dip galvanized finish provides a corrosion resistant zinc coating. Forged eye bolts are hammered, or pressed into form, which changes the grain structure of the metal to create a stronger, harder, and more durable product. When using nut eye bolts, the bottom of the shank protrudes through the bottom of the load in an untapped through-hole and is secured in place with a nut. These eye bolts are non-shouldered eye bolts, commonly referred to as plain pattern eye bolts. Designed without a shoulder, they can only be used for truly vertical or in-line lifts. Plain pattern eye bolts are not designed to be used for any type of side loading or angular loading. For critical or safety-related applications, see Lifting Eyebolts. If the eye bolt is not shouldered to the load, a second nut on top of the load should be used where possible.
Turned Eye Bolts
Turned eye bolts, also known as bent eye bolts, or wire eye bolts, are made from one piece of steel wire that is bent and shaped to form the almost closed eye on one end, with a threaded shank on the other end. These eye bolts are designed for through-hole applications and used primarily for light-duty applications. Turned eye bolts should not be used for heavy loads, which can cause the eye to open, or for angular loads, which can bend or break the bolt.
Rod ends appear similar to eye bolts, but have a thicker, smaller head in proportion to the body. They are designed to secure and suspend objects from anchor or pivot points. Rod ends are used in a multitude of applications such as steering, tensioning and controlling movement at pivot points. See more about Rod Ends by clicking here.
Common Finishes of Eye Bolts
Eye bolts are available in different finishes and coatings, which play a role in the suitability of the fasteners in different applications, such as enhancing resistance to corrosion from environmental elements or chemicals. Coatings also greatly effect consistency of torque values for installation, and ease of disassembly at the end of service.
Black or Plain Finish Eye Bolts
Eye bolts are unfinished or will have a minimally protective finish. Black eye bolts offer near zero corrosion resistance, though black oxide coatings or oiled coatings do offer increased corrosion resistance over unfinished eye bolts.
- Black eye bolts are commonly referred to as plain finish, black, black oxide, black phosphate, bare or light oil coated.
Galvanized Eye Bolts
Eye bolts are coated with a sacrificial zinc coating that acts as an anode to prevent the fastener underneath from corroding.
- Hot Dipped Galvanized: Fasteners are dipped in a bath of molten zinc.
Plated Eye Bolts
Eye bolts are coated with a thin layer of zinc, typically via electroplating.
- Plated eye bolts will not corrode as quickly when covered with this protective coating, even when a scratch or cut exposes the steel to air or moisture. The zinc or cadmium plating will always tarnish and corrode first.