E-Z LOK 400-4 Threaded Insert, Brass, Knife Thread, 1/4"-20 Internal Threads, 0.500" Length (Pack of 25)

I assembled a dresser from a big blue box store with four yellow letters and I wanted to be able to put casters on the legs of said dresser so that we could easily move it around while we decided where we wanted to place our furniture in our new apartment.TLDR; Installing these was easy. I drilled a pilot hole in each leg and then screwed these in with a flat head screwdriver. Then I screwed in the casters.It worked like a dream, but I should have reinforced the soft pine legs (or simply gotten a better quality dresser) When our movers rolled it out of the elevator to get it into the truck a gap in the threshold caught one of the caster wheels and the hardware busted right out of the leg like it was made of balsa wood.

I used these for screw-in casters on table legs. They're very sturdy. The only issue is getting them to start in straight. I used a miter gauge and kept checking them and a couple are still not straight. If I was doing a number of them, I'd invent a jig of some kind to hold them straight.

I was skeptical at first hearing about what size hole to drill and inserts not going in. One reviewer said to use a 14mm Forstner bit and he was right on. I was drilling into a maple glue up table top so it was the worst of situations for the inserts, super hard wood. The 14 mm bit worked perfectly and the inserts screwed in without flaw. I also bought the drill adapter specifically for the inserts which was worth every bit of 10 bucks, it made for very secure turning in the inserts. Be sure to put your drill on low speed and start very slow, making sure you are as plum straight as you can be with a handheld drill. Low and slow is key for these inserts, don't try to spin them in on high. I only screwed 1 out of 12 up and that's because I started crooked and though i could straighten as i went but no, you should immediately back out and start again. I barely got the insert out because the adapter bit is designed to put them in and not so much to remove them, it tore up the top edge of the insert but did get it out. Again, this was only the case because it put it in crooked to begin with, I was easily able to remove the ones that were put in straight. All in all this product worked perfectly as well as the optional adapter which is a must have. Also worth noting, i bought the M8 bolt size insert, the adapter bit fits down into the 14mm pocket which allows you to turn the insert flush or even below the surface if necessary.

I purchased these to repair hardwood dining room chairs where the original hex drive flanged inserts were failing and pulling out. After reading many reviews I agree with the negative feedback 100% and can sympathize. Unfortunately, it’s not a simple slam dunk installation and having fundamental understand about how threads stretch and cut into wood helps. Does insert stray and go in crooked? Yes. You need to watch after several turns and see if it’s going in straight enough. I was replacing hex drive inserts that completely lost its holding power and luckily, there’s enough forgiveness when joining with fasteners that being slightly off was ok. Does a screwdriver work? No and as other reviews mention, the brass tabs break because for my project, the torque needed was applied with a socket wrench in the >20ft-lb range and no way will a screwdriver apply that without slipping. Lubricant help? Yes, I used Titebond for a more permanent installation and the glue post cure helps with lubricity when turning. Did I use special tool? No, and I can see some reviews spending a lot for this specialized tool and it breaks. I used a fastener with same internal thread and nut. When driving insert to the desired depth, quite often the fastener will not release from insert because of thread stretch. You have to know how to release and trial and error. Don’t get frustrated and maybe even practice. For my project, the EZ LOK knife insert worked well after a little research before using. Your application may be different with less forgiving requirements so I can see how people give 1 star. Good luck.