Rigging Screws and Turnbuckles, also known as bottlescrews, are an integral part of the standing rigging on a yacht.
Turnbuckles are an extremely important component in a yacht's standing rigging because they provide the adjustment required to tension the shrouds and stays correctly.
Rigging Screws, also known as rigging tensioners, are generally manufactured from AISI 316 marine grade stainless steel but the turnbuckle body (barrel) may be manufactured from even stronger more resilient metals e.g. manganese bronze, high tensile bronze alloy with a chrome finish or naval grade, ultrasonically inspected aluminium bronze.
Rigging Screws are initially best set up 2/3 open to allow for good adjustment either way.
Bear this in mind when setting up the lengths of your rigging wires.
Rigging Screws facilitate adjustment of the tension in shrouds, stays, guard wires and lifelines.
This is achieved by means of different handed internal threads on each end of the barrel (open or closed body).
Each end of the body therefore has one Left Hand, one Right Hand thread
The two external end parts of the Rigging Screw also have different handed threads i.e one Left Hand, one Right Hand thread in order to match the barrel correctly.
This means that as the body of the turnbuckle is rotated, both fittings attached to it either screw further in or further out to tension or slacken the wire rope. This allows you to easily add the right amount of tension to a wire system.
STA-LOK have produced this picture to help recognise the two different threads so that the rigging screw can be fitted together in the correct fashion:
Take a close look at the thread on the fitting. The thread will be noticeably higher on one side than the other as the thread travels around the fitting.
The side that is higher is the direction of the thread. This can be observed at any position of the thread by simply following one crest around.
Jimmy Green Marine offer a range of 5 different Turnbuckles:
- Petersen Stainless Steel Rigging Screws
- Petersen GT Turnbuckles
- STA-LOK Bronze Turnbuckles
- STA-LOK Supajust Turnbuckles
- STA-LOK Stainless Steel Turnbuckles