INDUSTRY NEWS / EYEBOLTS
UPDATE TO AUSTRALIAN STANDARD FOR COLLARED EYEBOLTS AND EYENUTS Eyebolts and eyenuts are used everyday in the lifting sector and changes to the Australian Standards will impact everyone. Charles Bell, Senior Lifting and Product Engineer, explains. LAST YEAR saw the release of a new Australian Standard governing the humble collared eyebolt. Australian Standards have valuable guidance for users of lifting gear and AS2317.12018 is no exception. It contains extended detail for use as well as new requirements for markings and inspection. This new Standard concerns low tensile eyebolts and eyenuts, which are called grade 4 to align with international terminology. THE OLD FAMILIAR Collared eyebolts are a simple device. They have an eye at one end which we can connect to our slings and a thread which we can connect to our payload at the other. While eyebolts themselves have changed little over the course of many years, the changes in the Standard are worth exploring. EYENUTS ARE NOW INCLUDED The new Standard now includes comprehensive treatment of both eyebolts and eyenuts. Eyebolts have an external thread and eyenuts have an internal thread. The thread is fundamental to a safe connection to the payload. These threads come in all shapes and sizes and are of course internal as well as external with the result that eyenuts are commonplace. The previous (1998) version of the Standard remained silent on the issue of eyenuts. Including them now enables the Standard to open up a more thorough conversation about the threaded connection in general. This is valuable because it is important that we get the connection right. 30 / CAL March 2019
THE SUBSTRATE It is vital that the threaded connection to the payload is safe and does not overstress the supporting material with its threaded interface. AS2317.1 calls this supporting material the substrate. Contained within the Standard are clearer rules to set out how strong the substrate material must be. A common pitfall is to fit an eyebolt to material which is simply not strong enough. One of the advantages of grade 4 (lower tensile) eyebolts is that when lifting softer materials, the grade 4 eyebolt can offer a larger thread to use with a soft payload. This is often at a lower cost than a high tensile lifting point of similar overall size. Matching the strength of an eyebolt to its substrate is vital to achieving sufficient strength and the new Standard provides guidance on a variety of common scenarios such as: use of a nut behind a plain hole, use of reinforcing washers, and use with threaded studs. Common questions such as what grade of nut or stud to use and what tolerance on hole size is required are now addressed. THE IMPORTANCE OF THE COLLAR The defining feature of a collared eyebolt is of course, the collar. A dogger might instinctively make the distinction between a lifting eyebolt and something else purely upon the presence of the collar without giving much thought to what it does. Within the new Standard the role of the collar is now emphasised. When we use any collared eyebolt (or eyenut) it is important to understand what this means and how vital the
Charles Bell.
‘collar’ of the eyebolt is. Wherever an eyebolt is loaded in line with the axis of its thread (in a straight line), the central threaded part can contribute fully towards resisting the lifting forces. Wherever an eyebolt is loaded away from this axis, then the strength is greatly reduced and the collar with the support it provides becomes vital to resisting the lifting forces. Without the support of the collar, damage in the form of a bent eyebolt is often the end result. The new Standard provides clearer diagrams and instructions for avoiding this type of damage when the eyebolt collar cannot directly contact the payload, including the use of shims and packing washers. Ensuring that the collar is fully
