FLAT HEAD EYE BOLT:

Flat Eye Head Bolt specification covers eyebolts designed to use with shackles. Hence the provision of a collar adds  to the strength of an eyebolt and eye– bolts without collars are unsuitable for inclined loading. Whereas these eye bolts are designed with a shoulder at the point where the eye and the shank come together. This shoulder design reduces bending stresses on the shank. And allows the eye bolt to be used for angular lifting if the shoulder is properly seated in the load. In Brief An eye bolt is a bolt with a loop at one end. They are used to firmly attach a securing eye to a structure, so that ropes or cables may then be tied to it.

General:

What Are Eye Bolts? One of the most commonly used pieces of hardware in material handling. An eye bolt has a simple design, consisting of a threaded shank with a ring/eye at one end. Eye bolts are threaded to structures such as wood or steel posts and often supported by a nut In Fact Eye bolt strength at 45° horizontal angle drops down to 30% of vertical lifting capacity. Use a swivel hoist ring for angled lifts. The swivel hoist ring will adjust to any sling angle by rotating around the bolt and the hoisting eye pivots 180°. For eye bolts the standard is BS 7883:2005, and testing should occur at least every 12 months. For class A1 categorised anchor points testing should be conducted in accordance with BS EN795 standards and the testing frequency is increased to every 6 months.