How to Measure the Size of Turnbuckles?

How to Measure the Size of Turnbuckles?


You can through read this article to understand the methods and techniques of measuring the size of turnbuckles, so as to better adjust turnbuckles when meeting different application requirements.

How to Measure the Size of Turnbuckles?
fork turnbuckle
turnbuckles are fittings used to tighten or loosen the tension on guy wires to move, level, or secure the object connected to the guy wire. The fitting consists of two threaded rods that terminate in eyes, hooks, or jaws.

When preparing to secure a structure using a turnbuckle it is important to know how to correctly size the turnbuckles. Sizing a turnbuckle means selecting the turnbuckle that can support the appropriate load weight to hold the tension required on the guy wire and the end type that will fit the size wire required by the load. The following is a detailed introduction to the methods and techniques for measuring the size of turnbuckles.

Things you will need

(1) Caliper ruler

(2) Straight ruler

Measure thread dimension and take-up

(1) Make sure the turnbuckle is completely closed by turning the center frame (the take-up) so that the two threaded rods are fitted through in a clockwise direction until the ends of the threaded rods touch.

(2) 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'.

(3) 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".

(4) 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 a load capacity, there will not be duplicate threaded diameter and take-up measurements for different load capacities.

Measure the eye, hook, or jaw

Use a caliper ruler to measure the widest part of the inside of the eye. Note this measurement and label it "S". For hook ends, use a caliper ruler to measure the inside width of the opening in the hook and label it "D". For a jaw end, use a caliper ruler to measure the width of the inside opening of the jar and label it “B”.

Convert the measurement from standard to decimal using a conversion calculator. Find the measurement that matches the end measurement on a turnbuckle size chart to know the load capacity. Turnbuckle charts are standardized. The label given the measurement (S, D, B) will have a corresponding column on all charts.

Measure the diameter of the guy wire to be used or the diameter of the bolt on the Crosby or u-clamp to be used to connect the wire to the hook or jaw, to make sure that the wire will fit the end on the turnbuckle.


(1) Select the next largest load capacity if either the 'A' and 'BB' load capacities or the end load capacity is less than what is needed.

(2) The wrong-sized turnbuckle can cause the guy wire to fail by being unable to support the load, releasing the support tension in the wire. This will cause the object supported to fall, which can cause serious damage and injury.

It is very necessary to learn how to measure and adjust the size of turnbuckles through the above methods, which ensures the stability and safety of the fixed structure. If you want to know more about turnbuckles after reading the above, you can contact TERADA for a comprehensive solution.

TERADA has become a leader in the hardware industry by virtue of its excellent R&D technology and exquisite manufacturing technology. Our products are sold all over the world and used in all walks of life. In order to ensure the quality of products, we are also equipped with a professional quality inspection system and a comprehensive management team, which can control the manufacturing and export of products in all aspects. If you want to buy our turnbuckles, please contact us immediately!