FLK Tech 5/8" Plug Wedges and Feather Shims Concrete Rock Stone Splitter Hand Tools 16mm (8, 5/8")

Great value for the money and they work just fine. Just take precautions regarding the large amount of dust the drilling of the holes will create - a normal issue with using a hammer drill on stone or concrete. I was able to trim back some ground level stones of a rock wall that were a hazard to my lawn mower without disrupting any parts of the rock wall. Attempts with hammer and chisel did not work well, but these wedges and feathers worked perfectly, and those stones were really tough.

Used them to fracture a large block of concrete. Used a 5/8" drill bit for foot deep holes. Tried a 1/2" drill and they do fit snugly, but I don't recommend that because it caused me to bend one of the feathers. The big O Ring that holds the wedge and feathers together is nice, but keep spare o rings because they get beat up and are a consumable. The wedges do mushroom and chip from the hammer, so wear safety glasses. Mushrooming happens.

Durable and super easy to use. Only problem was 2 of the rubber rings were broke upon arrival but just went to parts store and got new ones (less than a dollar) but work great!

Works great amazing value but is kinda short but will do medium sized rocks easy to use

They work as they should. Order a bigger pack to make sure you have more then you think you need. If you don't have enough of them while trying to break big boulders then you end up wrecking the wedges having to beat on them way to hard. Or you run the risk of not being able to split the boulder and you can't get the wedges out. Order extra and keep spacing at about 4" apart.

These worked wonderfully splitting concrete. I had previously tried using them on a large granite boulder and it seems to split off in layers layers. For that Dexpan worked better but takes a couple days.1. Snap some lines across whatever you want to split.2. Mark up where you want the wedges and spread them evenly across what you want to split. I placed one ~ every 6inches.3. Hammer drill 9/16" holes deeper than the wedges, as it's hard to clear out all the dust and you will lose depth.4. Place the wedges in the holes. Use a small handheld sledge and give each wedge 2 taps, going down the line, the 2 taps on the way back. Go back and forth until the concrete starts to split. It can take a little time for the hairline crack to start to show. Keep going until the concrete spreads and you get a gap...but don't pound the wedge to the surface.**Don't drill 5/8 in holes. You could but the wedges may go to low. 1/2" holes could work on thinner concrete, but are a bit too small and you may bend a wedge.

Broke up multiple 30 inch rocks with feathers. Recommend getting something to blow of dust from holes and a magnet to retrieve pieces if the fall into the drilled hole.

Had. Concrete pier under my house I needed to remove. Drilled some holes. Hammered these in and worked perfectly.