Among the tools you may not know we rent are turnbuckles. These underutilized pieces of rigging hardware provide a mechanical means of adjusting a load in cases of offset center-of-gravity (CG). Additionally, they can also be used to adjust tension in the sling(s) that could be caused from an offset CG. When considering ways to achieve a perfectly level lift, there are many options, but none as simple as a turnbuckle. Today, we will break down what a turnbuckle is, composition of a turnbuckle, the different configurations and how they work.
What is a turnbuckle?
At its core, a turnbuckle is a piece of rigging hardware consisting of a body and two threaded end fittings. These are utilized, as mentioned above, primarily to remove slack in slings and to adjust tension in a tensioning system. Turnbuckles can also be paired with another when additional length or adjustability is needed.
Crafted of either galvanized or stainless steel, our turnbuckles have tempered end fittings and normalized bodies with enhanced impact properties. What this means is that turnbuckles have greater toughness at all temperatures, providing peace of mind on the job site.
Parts of a turnbuckle:
Turnbuckles are very simple in construction and are comprised of three distinct parts – the body and two threaded end fittings.
The body is what is used to adjust the tension and holds the two end fittings in place. There are two possible body styles available – closed, also known as a pipe body, and the more common open configuration. The body is threaded on each end and rotates to either extend or retract the end fittings. One note, however, is that the body can only be adjusted with no load. Once load is applied, the body is locked in position due to tension on the unit.
The End Fittings:
Eye – With a teardrop shape, the eye end connects to a shackle with the pin running through the eye. This is the most common end fitting in most rigging applications and also one of the safest. Eye ends connect to a shackle prior to coming in contact with the sling, ensuring proper load distribution
Jaw – Jaw ends are “U” shaped and have a through pin held in place with a cotter pin. Jaws can be used in direct contact with a sling – provided it’s wide enough to avoid bunching – or lifting lug. You can also run a shackle through a jaw, but that is more commonly used with eye ends instead. The cotter pin is the most important piece of a jaw end, ensuring the connection remains secure.
Hook – Hook ends lack a safety latch, which makes them the least used configuration, but each has merit. So, when would you see a hook end used? Frequently, these are utilized for temporary connections and guy wire applications. This due to the ability to quickly connect and disconnect the load. Hook ends should never be used when the tension could release on its own. While under tension, the hook is stable, but once there is slack on the sling, it could easily slip off. For this reason, one of the other end fittings should be the only ones considered for lifting applications.
What are the different configurations available?
Turnbuckles are available in five configurations: Eye and Eye, Hook and Hook, Hook and Eye, Jaw and Jaw and Jaw and Eye.
- Eye and Eye – Mentioned above, eye and eye are the most frequently rented configuration. Given the flexibility of applications, eye and eye turnbuckles can be used nearly anywhere.
- Hook and Hook – This configuration is what is referenced above in the “hook” section. This style of turnbuckle is best suited to very niche projects where quick connection and disconnection is necessary.
- Jaw and Jaw – Jaw and jaw is used to join the rigging to the turnbuckle and direct to a sling or lifting lug
- Hook and Eye – Similar to hook and hook, the only difference is that the eye end allows for one secure end attached with rigging hardware.
- Jaw and Eye – Jaw and eye configuration is used nearly the same as eye and eye with the flexibility to directly connect to the lifting lug.
If you have additional questions about turnbuckles or need high-quality, inspected, tested, and certified lifting equipment rentals, LGH has you covered. Click to chat with a live rental support specialist or call 800-878-7305 now.