In this guide, we’ll look at the different types of turnbuckles at the end fittings, installation, and uses.
1. What is a turnbuckle?
A turnbuckle also is known as rigging screw, tensioner, straining screw, barrel strainer, or adjuster, is a device for adding or releasing the tension or length of ropes, cables, tie rods, and other tensioning systems. They are used for rigging or tensioning wires, ropes, rods, etc., typically within industries such as oil and gas, construction, shipping, mining, and fishing. You can easily twist the turnbuckle body to expand or contract the length, without rotating the end fittings on both sides.
2. Turnbuckle material
The most common turnbuckle materials are carbon steel and stainless steel. We usually add a zinc layer on the carbon steel galvanized turnbuckles with protection against rust and corrosion, while stainless steel turnbuckles can be used in high chloride or high moisture environments, as they offer a higher level of corrosion protection. If corrosion is a concern, stainless steel turnbuckle is your best choice.
3. Turnbuckle end fittings
Rigging turnbuckles are available in many different types, sizes, but basically there are three primary turnbuckle accessories: a turnbuckle body, a right-hand threaded end fitting, and a left-hand threaded end fitting.
There are two main types of turnbuckle body, closed body turnbuckle, and open body turnbuckle, please refer to the following items.
The turnbuckle end fittings conjunction with other anchor points to adjust the tension of the cable or rope by turning the turnbuckle body.
basically four main types of end fittings including:
- Hook end – are used for temporary connections and are much easier to install and attached or detached from other rigging components than jaw end turnbuckle and eye to eye turnbuckle. However, it is far less practical due to the lack of a safety latch, which may unexpectedly release from attached rigging components, cause the hook to dislodge.
- Jaw end – are composed of a jaw, bolt, and nut, but depending on size, some jaw turnbuckles only come with a cotter and a pin. They can attach the wire rope sling straight onto the jaw end and pin to the lifting eye bolts and lugs, which cannot be opened.
- Eye end – are intended for straight-line pulls only or in-line applications not for lifting purposes. They have no moving and opening parts, designed for a shackle or quick link to go through on each eye end, then attached a wire rope sling or other approved rigging components.
The turnbuckle ends can be combined according to different needs that whether the solution is permanent or temporary, so there are many different types of turnbuckles.
4. Different types of turnbuckles
We carry a full line of turnbuckles from the small turnbuckle to the large turnbuckle. The most common turnbuckle types are:
5. How to measure a turnbuckle?
Turnbuckles are composed of two threaded rods that terminate in eyes, hooks or jaws. It is important to know how to correctly measure the turnbuckle when preparing to secure a structure. You can follow these steps to measure turnbuckle dimensions:
- Make sure the turnbuckle is completely closed by turning the center frame (the take-up) that the two threaded rods are fitted through in a clockwise direction until the ends of the threaded rods touch.
- Measure the diameter of the threaded rod with a caliper ruler. Close the calipers on the threaded rod just above the first thread near the eye, hook or jaw. Make sure the calipers are not on the thread itself or too far up from the thread that the calipers are measuring where the rod begins to flare into the end eye, hook or jaw. Note this measurement and label it ‘A.’
- Use a straight ruler to measure the length of the inside of the take-up. The take-up is what is turned to loosen or tighten the turnbuckle. The inside of the take-up is the rectangle inside the frame through which the threaded rods can be seen. Measure end to end of the inside of the frame. Note the measurement and label it “BB.”
- Locate the listing on a turnbuckle load chart that matches the measurements for A (the threaded diameter) and BB (the take-up). Note the load capacity of that turnbuckle size. Each turnbuckle size is unique to load capacity, there will not be duplicate threaded diameter and take-up measurements for different load capacities.
6. How to use a turnbuckle?
Before the installation of any type of turnbuckle hardware, it is important to know the right and left thread and the Working Load Limit (WLL), click here for more knowledge of M.B.S & W.L.L. By common convention, most threads are the default for right-handed screw threads. Therefore, most threaded parts and fasteners have right-handed threads.
When seen from a point of view on the axis through the center of the helix, it moves away from you when it is turned in a clockwise direction and moves towards you when it is turned counterclockwise. This is known as a right-handed (RH) thread because it follows the right-hand grip rule. Threads oriented in the opposite direction are known as left-handed (LH).
So commonly you can see the letter “R” and ” L” on both turnbuckle body end.
Keep in mind of straightforward steps:
- First, unscrew end fittings from the turnbuckle body until completely extended to the full take-up length.
- Second, connect end fittings on either end to desired securement point, for eye end and hook end fittings, simply loop it through whatever securement point it will be connected to, as for jaw end fitting, unscrew the bolt from the jaw, place the securement point between the clevis ears (thimble, eye bolt, etc), then place the bolt through, and screw it shut.
If you want to get more useful knowledge about how to use a turnbuckle, you can contact us by email at [email protected]. We will be glad to share with you more useful information.