DIN 444 Eye Bolts

DIN 444 specifies eye bolts with a forged or machined circular eye at one end and a metric threaded shank at the other. In industrial procurement, these fasteners are also known as fish eye bolts, collar eye bolts, or precision eye bolts.

The standard defines three configurations: Form A with tight tolerances on the eye bore and thickness, Form B with standard commercial tolerances, and Form LB with an extended thread length for greater adjustment range.

Typical applications include lifting lugs, tie rods, hinge pins, clamping fixtures, and mechanical linkages. The eye provides a connection point for hooks, cables, pins, or rods, while the threaded shank allows the bolt to be secured into a tapped hole or through a nut.

Buyers select DIN 444 eye bolts according to the load direction and the required level of eye bore precision.

The eye bore of Form A is machined to close dimensional limits, making it suitable for joints where the bolt pivots on a precision pin or shaft.Form A is specified for precision assemblies where the eye must rotate smoothly on a fitted pin.

Form B covers general-purpose lifting and tie-down tasks. The material and strength grade depend on the working load and environment; carbon steel grades cover most mechanical applications, while A2 and A4 stainless steel are specified for corrosion resistance in marine, food, and chemical environments.

Form LB is commonly used where the bolt must pass through a thick plate or where axial adjustment is needed during assembly.