4Z1 4" Handheld Concrete Core Drill with Carrying Case 110V 1500W 2-Speed Diamond Wet Core Drilling Machine, 2100/950 RPM, Portable

I thought about renting a drill and I am so glad I did not because first of all this drill was almost the same price as renting one, second of all, after I drilled two 2.5" holes 7 inches thick horizontally I am really glad I did not rent one because I would have had to rent it twice as long as I thought it would take. This drill does not cut slow compared to others but when you only cut holes every few years it takes longer than you think. I was tired after the first hole and after the second hole I had to wait a couple days before I felt like drilling the other small ones so just after a few holes this drill has paid for itself and now I own it. I caught a long bit on it a couple times and I was worried that the delay in the clutch would catch me off guard but six inches deep and bound up did not twist my arms or wrists like I thought it would. I am 5' 10" tall at a stout and strong 175 and I could handle the catch in this drill pretty good. I have not hit any re-bar and I have been told that that is what causes the most damage but I did bind this drill up pretty good and once I even bound it up by trying to untie the kinked water line with my left hand as my right hand took the entire force of the bit catching (didn't twist my right hand like I thought it would and was a long ways away from breaking my hand or wrist) I almost gave this 4 stars because the crappy plastic water connection that comes with this drill has to be replaced first thing with a brass one that won't leak. I had one on hand and if you don't care about water leaking then this drill is a great deal. If you do care about too much water in places you don't want then be prepared and buy a garden hose adapter made out of brass and replace the one this drill comes with before you start drilling . all in all 5 stars.

Purchased to cut through 4”n20 year old concrete slab to move a drain line. Used a 6 1/2” diamond core saw with masonry guide bit. The core drill low speed setting a too fast to use for starting saw as it would walk. Used a SDS variable speed drill to get a slower start speed and get the core saw to cut a slight groove. Once I had a good cut started I switched over to the core drill, core drill gad no problem cutting through the 4” slab 2 times within a relatively short time frame. I did not use water libe for drilling due to the mess, I just poured a little in the cut groove along and along to cut diwn on dust. My core saw was a dry saw so not a big problem It would be nice if the water hose had a quick disconnect on the drill side as it was a pain trying to drill with it attached but not being used. No idea as to longevity, it seems to be reasonably well made and I did not notice any problems with overheating during my use. Note I was using a larger core saw than suggested max and I was not in a hurry so did not push the drill hard. Seems to be ideal for a DIY person not doing constant drilling or possibly use by a plumber or other trade that don’t need to drill cores daily.

So far we've drilled about a dozen holes with this drill. Nothing to complain about given the price. Although not recommended we've had no problems using this without a stand to drill 4" holes... however we do create a "starter hole" with a different bit on our hammer drill. I wasn't able to start the hole with the bit alone, it just skated away. The bubble level on top is extremely useful to keep it straight and level, we're coring cement decks for swimming pool rails and setting these level and plumb is very important. When using it handheld there's a tendency to lean forward and the bubble level keeps you on track if you watch it. We also bought the bluerock coring bit, that we haven't had as much luck with, it's already broken a tooth.

I was a purchasing agent that built concrete building from the ground up. Core drills are used in the process as needed. We bought big brand names that would last awhile. Until we tried one of these ! It out lasted the others ! I mean this is a go to machine, it is basic, no wobble for a hand held tool. Here is the thing not mentioned in the ad. In the first 6 month to a year, the internal clutch has to be tightened. It requires disassembly (messy) to do this. But it will last years even with heavy use. The others cannot compete.

In the process of building our retirement home we have made so many purchases that I have not had time to write reviews for every item we've acquired. This coring drill is such an exceptional machine that I had to take a few minutes to share a few thoughts. First, we purchased this drill as a one time use machine. Since its cost and the cost of the bit were less than the cost of renting a machine and bit, we purchased rather than rented. For the price, I expected something that would do the job and then be somewhat worn out. How pleasantly surprised we were to receive a smooth, quiet, and powerful machine that performed really well. With little more than moderate pressure and a little patience, (10 minutes or so each), we had three 3 inch holes in 6" cured, fiber reinforced concrete with imbedded rebar. I have to think this drill would make the cut for industrial use. One niggling little thing - as others have reported, we too got a shower from the water hose. While the knob for the side grip handle had to have been tightened by King Kong, the screws holding the hose to its fittings were little more than hand tightened. We'll take half the blame for the shower because we had fair warning, but the people on the assembly line should really pay closer attention to this detail. It would take so little effort to avoid creating an unnecessary and annoying distraction from what is otherwise a really fine package. We took less than a minute to tighten the screws and all was well. We'd buy this drill again.

well made for the price

Tool worked well! The water hose is BAD!. WILL NOT TIGHTEN UP HOSE IS TO BIG FOR THE FITTINGS. SO EVERY CLAMPING POINT LEAKED. I will buy the correct hose and all will be good. Like i said tool worked as promised just the hose sucks!!

I have used this machine without stand for few months and drilled with it over 76 holes 2” and 2.5” all through reinforced concrete (it takes about 20 minutes each if there is rebar), few others 4.5” The supplier guided me on how to perform the maintenance service adjusting the clutch (tightening to 11 ft/lbs with a torque wrench), so don’t worry if the machine starts skipping The water connection that comes with this drill is awful and has to be replaced, but I still give 5 stars This machine will pay for itself after couple of jobs; you will not regret buying it. Best value *****