E-Z LOK Knife Threaded Insert for Soft Wood, Zinc Hex-Flanged Thread Inserts 3/8-16 Internal Threads, 25mm Length Pack of 25

Work great !

I ordered these 3/8-16 E-Z LOK Knife soft wood threaded inserts for the purpose of installing casters on a workshop table that I built out of pallet wood, which I presumed would be softer than regular hardwood such as maple or oak. However, it turns out that pallet wood is harder than pine or poplar, for which they are apparently designed. The package recommends drilling a 15/32" hole for the inserts but when I tried to screw the insert into the wood, the insert split before I could get it all the way in. So, I drilled a 1/2" hole and applied a small amound of grease to the insert and everything went together very smoothly. I'm happy that I was able to adapt these inserts to my particular situation and I would order them again.

Inserts arrived well packaged in a bubble package. Inserts were in a heavy sealed bag inside the mailer. Inserts look to be die cast and the finish is excellent. Price was excellent for the high quality. Delivery was quick and no trip to the store...saves time and gas money. I recommend buying in bulk from this supplier.I used them to mount some 8" casters to a dolly I had made for moving some furniture. I drilled 1/2 in diameter holes in the wood frame about 1 inch deep. Drill slightly deeper than the length of the insert. I screwed them in using a metric hex head Allen wrench, it fits perfectly. Casters are holding tight using some grade 8 3/6-16 bolts I bought from Amazon too.

These threaded inserts are great for soft-woods that either haven't been kiln-dried to increase their hardness, OR for woods that have been properly prepared. I used these with eastern poplar that was planed into 2x8x96 boards with pre-drilled holes using a basic power drill and a 1/2' bit. To install these you have two options, get a 3/8" - 16 hex bolt and some corresponding nuts. Cutoff the hex-head so the bolt is just a straight shaft, and thread the nuts on so only about 1/2" of the threads are showing, apply a drop of basic corn or vegetable oil and then thread the insert onto the bolt. Insert the other end (the end you cut the head off of) into your drill and adjust the power if you can to a medium setting. GO SLOW! Drill very slowly otherwise the nut will start to bore at the top of this zinc insert. They are extremely soft and will not hold up to a lot of torsional stress. The thing to note here is that you MUST prepare the holes for which this go into PROPERLY! The inserts themselves taper from about 3/8" at the bottom to 5/8" at the lip on the top. A simple 1/2" hole will be fine. You could use some liquid nail or epoxy to really lock these in. I recommend slow forward drilling and a quick burst in reverse to remove the makeshift driver bolt you created before hand.The other option which is probably easier is to just use a drive tool. You may get better results then I did, although mine turned out ok with the above mentioned process.This is my first time using these larger inserts for a very large desk I'm building for my father. They are to attach large 12 gauge steel L brackets to legs so the entire desk can be disassembled with a single allen key and about 20 bolts. Once the inserts are installed they hold quite well IF you've done things properly. Whatever tool you use to install these, you really only want the bolt or screw to be able to get no more than 1/4" of the threads to clamp on to. Otherwise, the zinc is going to lock down on your installation bolt/screw and freeze up.I'm giving these a 4 out of 5 stars for two reasons. They're WAY too soft. Granted, these are the only ones I could find on Amazon, and everything else was already in my cart. Partly my fault, but then again, according the tensile strength these should be stronger. 'm deducting also for the fact that there is a small shelf at the bottom of the insert (you can see it in the picture) that causes issues when installing them. You might want to even consider just using a dremel to remove that bit. Amazon got these to me fast and fairly cheap all things considered.Overall, be sure you are using these in a soft or softer wood such as pine, cedar, poplar, etc. I HIGHLY doubt these would play well with hardwoods like hickory or maple. You *might* get these to play well with some oak, but then again, it's iffy as was with the poplar (it's not really poplar, but the common-name is yellow poplar even though it actually belongs to a different genus of woods) I'm using. If you need these for a concealed area to fasten a bracket or something else they work well. Not great, but well enough to warrant their low price and decent value.

1/2 bit worked great for the 3/8-16 ones. I wanted full thread engagement so I was torn between the piloting advantage of a tapered fit vs the holding strength of a straight fit, but after running a bunch of test holes, the 1/2 hole had good thread engagement from the get go and it allowed for plum install. So even though your eye may lie to you, use a 1/2 bit to drill the hole fit the 3/8-16.

(11/27/16)I bought these for a project these past few days and have been very satisfied with them. At first I was a bit leery due to previous reviewers saying the threading was really poor, but I really needed these now and 50 cents per piece at my local Anawalt Lumber was not an option. Once prime delivered them I immediately examined them and ran a quarter inch bolt through EACH one to find any faults. Installing messed up ones and then having to take the project apart at a later date was not part of the plan. It was tedious but had to be done. Long story short NOT a single messed up insert. I used about 120 of these for a project with MDF. Like another reviewer suggested, I utilized a 5/16" bit to make my holes. The inserts fit really snug and it was a good call by that reviewer. Because I can see these inserts tilting abit when screwed into a larger hole. will post pictures.Happy with my purchase, I recommend them to anyone looking for this of insert.BTW: you can thread from either end.

I used these for two projects so far. I wanted to add castors to a workbench, to raise it and make it mobile at the same time. I took a couple of pieces of 2x4 cut to the width of the bench and inserted 16 of these, 4 per caster. I was then able to screw the 2x4s to the bench and then bolt the casters to the bottom of the bench. Very secure. The second application was securing a mailbox. I wanted blind fasteners but I didn't want to have to rely on wood screws. I cut a piece of 1/2" plywood to fill the gap under the mailbox I chose and drilled it to match the mounting points and added inserts. I screwed the plywood onto my mailbox post and could then bolt on the mailbox. it is so much easier to use the bolts than to try to start screws while reaching to the back of the mailbox. And the mailbox is much more secure. The flanged bolts I used won't pull through.

works