THE BEAUTY OF USING THREADED INSERTS TO ATTACH METAL LEGS
The beauty of using threaded inserts when attaching metal table legs is how easy they are to install and use. It will require accurate placement but don’t worry we will demonstrate how in this article. Beyond installation these inserts allow anyone to simply set up or take down the table without jeopardizing the attachment points strength. That’s a huge benefit all in itself.
Over time tables get bumped, moved around, and shifted about causing the old shaky leg syndrome. As a rule, it’s a good idea to check leg fasteners on tables periodically just to keep things solid during the year. If a little wiggle is detected then simply re-tighten the bolts without worrying about stripping the original holes or better yet completely remove the bolts re-thread lock them before reattaching the legs and you will be good for years of wiggle free durability.
We prefer using furniture bolts for our table legs mainly because there are a number of unique profiles available in different colors that you may otherwise not find at the local hardware store. However, most any bolt can be used as long as the bolt size matches the threaded insert. We really love the mat black furniture bolts for this project because they blend well with the table leg themselves. If you decide to go one step further and recess your metal table legs for a sleek look then you may want to check out how to make the jig for repeatable exact leg placement.
If you would like to experience the video of this article the link below will open in another tab allowing easy reference back to this article. Don’t forget to hit the subscribe button on your way by. Thank you!
Choosing Metal Legs To Match Table Height
The coffee tables we build use a standard leg height of 16″ with a tabletop depth of 1.5″. Including the top, the measurements from the floor to the top to the coffee table is 17.5″. This is a comfortable and convenient height for most furniture. This is what we prefer but there is a wide range of leg lengths available to suit pretty much any height preference.
It is important to mention that not all metal legs are equal in value or quality. It’s like anything else but depending on which brand of metal legs some come with additional feet that either snap-on or attach in some way which is a nice bonus. If the optional feet are used then it will be important to account for an additional ½” of overall table height.
Adding a 1/2″ for the feet and the tabletop thickness may not make a major difference for either coffee tables or sofa tables but if you were determining height for a dining table then a tabletop that is 1” vs. 3” would make all the difference in the world considering the standard dining table height is 30”.
For this build, we used metal hairpin legs (Amazon Link). However, any type of metal legs can be used with threaded inserts as the process will be the same.
Tools / Hardware / Supplies – Amazon Links below
Drill Out Table Leg Factory Holes
For this build, we upgraded the factory screws that come with the hairpin table legs to 1/4″ (20mm) button head bolts. For this reason, we slightly enlarged the factory leg holes to account for the bolt adding additional wiggle room for good measure. This will ensure a forgiving bolt to threaded insert line up when attaching legs.
We use a metal bit with scrap wood under the base to avoid blasting a hole in our workbench while preventing the possibility of chipping the factory paint. Any rough edges caused by drilling can be filed down at this point to ensure a flat surface
Marking & Drilling Threaded Insert Holes
Select the correct size brad point bit that fits the newly drilled out table leg holes exactly. The sharp pointy tip of the bit will provide an accurate center when drilling out the holes needed to accept the threaded inserts.
It is critical that the legs don’t move when marking the holes and you have the legs exactly where you want them to be attached. If the leg does move without you noticing it could result in misaligned holes making it difficult to adjust. The reason why the factory holes were made bigger was to counter this precision required allowing for a little wiggle room and ease of installation.
We use a 5/16″ Brad point bit to drill the holes for the Amazon inserts. Rampa will require a larger bit size. The depth you will want to drill will be just slightly deeper than the length of the threaded insert including any bolt that may protrude past the end of the insert.
The stop collars do make it nice and exact but it is possible to set your hole depth by taping the bit at the desired depth reference point. Either way will work, the most important thing is to drill the holes as straight as possible. Before drilling into the tabletop that you spent a considerable amount of time building test out the hole size on a scrap piece of wood first referring to the recommended manufactures guidelines.
Side note*** If the bolts you intend on using are longer than the combined depth of the threaded insert and the leg base plate you have a couple of options. Either drill the holes deeper to allow for the excess bolt length or cut them to a shorter length.
Threaded Insert Installation
Once the holes are drilled it is time to use the countersink bit (Amazon Link) to lightly clean up the insert holes. This is optional but does a nice job of cleaning up any tear-out and sets the inserts beautifully and flush.
Add a small dab of quick-set speed epoxy (Amazon Link) to the insert hole before screwing the threaded inserts into the tabletop. This will ensure a sufficient anchor point creating a bond that will be stronger than what can be produced with Blue Thread Lock. We will explain the use of thread lock at the end of this article.
For now, the most important thing is to ensure that the inserts are started straight which can be done by hand with the proper sized Allan key. If any resistance is experienced work the insert in and out until fully seated.
Attaching Hairpin Legs
This is where everything comes together, literally. After test fitting to ensure the bolt holes line up perfectly with your leg base it’s time to attach them. At this point, you have the option to thread lock the bolts in place or simply just screw them in. We recommend using the table without any thread lock for some time and if a leg does become loose down the road then consider it at this point.
The reason for suggesting thread lock is that the bolts will stay put longer resulting in a sold table for longer. Also worth mention is that using a blue thread lock allows you to slightly back off the bolt from tight locking it in place and allowing for any movement in the wood over the changing of the seasons.
And just like that another project complete!
As always, we encourage you to engage with us and comment below sharing your experience with threaded inserts. I will reply to each message and appreciate your contribution.