The acoustical suspended ceiling industry uses eye lag screws almost exclusively to hang ceiling wires because they are economical and can be installed quickly and safely from the floor. These screws can be used in many other overhead applications such as hanging lights, signs, electrical cable, data communications cable (CAT5 and CAT6), HVAC ducts, electrical conduit, electrical trapeze, shielded cable and telephone wire to mention a few.
Description and load limits:
The eye of the screw is a 3/16″ hole punched in the flattened area. The flat end is used to twist the screw in. Screws designed for wood applications are about three inches long and have about an inch and a half of coarse threads that taper to a sharp point; there is no need to pre-drill a pilot hole. Pull out strengths vary with penetration and wood strength, but are usually more than the strength of the ceiling wire (600 pounds). Screws designed for sheet metal are case hardened and are zinc plated. They may have a sharp point (for thinner gauges) but usually have a drill point. Pull strength in sheet metal varies with metal thickness. Typically the thinner gauges (22 gauge) are allowed loads of 120 pounds. The thicker gauges (18 gauge) are allowed loads of around 240 pounds.
Methods of installation:
Telescoping poles tools are available that will reach a ceiling of up to 30′. These eye lag extension poles allow you to drive in the eye lag screw and “twist” off the ceiling wire from the ground. There are installation videos available online that demonstrate how easy these pole tools work. The LagMaster Plus is the most versatile of the eye lag poles available for this purpose as it can also be used to hang threaded rod, jack chain and spring steel clips from the ground. In some areas like California, eye lags screws pre-wrapped to ceiling wire are available. These pre-wrapped screws are used in order to make installation of ceiling wire even faster and to satisfy California codes for hospitals, jails and schools.
When you are up next to the ceiling you can use a drill driver jig to twist in the screw. This is the method used when you only have a few screws to install and you are already going to be on a ladder or scissor lift.
In summary, eye lag screws are surprisingly strong and versatile whether you are fastening to a wooden joist or metal decking.