Driving three-inch lag screws for installing hanging garage storage shelves is often a source of frustration for many people. They often experience them breaking. In this article I will give tips for how to prevent this problem.
The advice listed here can be applicable to any kind of use of lag screws, however my expertise originates from mounting ceiling brackets for ceiling mounted garage storage racks. These types of shelves require 2″ insertion into the stud. Most of these shelves include 3″ lag screws since they need to pass through drywall plus the width of the mounting bracket.
The most important thing to do in avoiding breaking screws is to always predrill the holes. Utilize a 3/16″ bit and drill down to the complete length of a screw. When you bore only part way then you will get significant resistance while driving the screw. I have heard some people have success making an additional hole inside that with a 15/16″ bit, but only drill as far as the smooth area of the lag screw. Understand that wood is a natural product, therefore there is a probability that you’ll run into a knot inside the wood. These areas usually do not accept a screw nicely and so they may force you to move your mounting point.
Secondly use an impact driver to drive the screws. The job can be difficult with a socket wrench. A cordless drill with the bit for sockets will carry out the work. However by far the simplest solution is to make use of an impact driver. I’ve found that I need to use both hands and stand squarely behind the drill in order to drive them successfully with a rechargeable drill. However, if I use an impact driver, I’m able to install the screws with only one hand and I do not have to align myself with the screw. This is particularly handy if I am on a ladder and need to reach out to the anchor point.
Another common problem is usually that people over tighten the lag screws. Do not over tighten the hardware. Should you crank on the head once the top of the lag screw is already flat against the drywall, you chance twisting off the head and having the threads stuck inside the stud. This could cause problems with connecting your ceiling mounting bracket because you might be installing across the studs, which means you will not be able to just slide the bracket over a bit to make a new hole. Turn the screws just until the head touches the ceiling bracket. The screws do not need to be tightened down any more.
Applying soap or wax over the threads could make it simpler to drive the screw. You’d be better off using candle wax if you can, because over time the soap can cause the threads to rust.
Should you be working with poor quality screws, think about making a visit to the hardware store for better quality screws. The grade and material of lag screws are marked on the head. No marks means the lowest grade 2 and it has the lowest tensile strength. Three radial lines means grade 5, a medium carbon steel that’s quenched and tempered. This grade ought to turn properly and not have regular breaks. The final and strongest ranking of steel screws have got six radial markings and therefore are grade 8.
Stainless steel lag screws would not have these standard markings on them, but have the approximate tensile strength of grade 5, nevertheless they may bend easier – more on bending later. Stainless will probably have something printed on the head, therefore you will not confuse them with grade 2. Stainless also is non-magnetic.
I wouldn’t advise reusing lag screws. Once driven, even only partially, the screw is stressed. The chances are greater it will break when you try to use it again. Which also suggests you shouldn’t install a screw by running back and forth into the wood to drive it to length. Lastly, a tiny amount of bend in the threads will keep the hardware from rotating and boring down into the stud correctly.