BLUEROCK Model 4Z1 2-Speed Concrete Coring Drill with Carrying Case

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.

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.

Was able to dry-drill two 10 inches 3.5in diameter cores in house foundation for WC fan duct. It was my first time ever at core drilling. Outdoors, in the fall, I went slowly, resting myself and the motor fdr 5 minutes whenever motor/drill body would get hot. I used a pilot bit and proper adaptors, goggles and mask. (I had also bought a wet core bit but did not use it fearing the proximity of water and electricity+ the need to insure water pressure +regulate flow. Just holding the drill, a real beast, is already quite a chore. My decision to dry drill was the right one, being all by myself.) This hi amperage drill is heavy and drilling is a real exercise for the arms and lower back. Clutch works and prevents grave and vicious wrist twisting when bit abruptly grips. Using the pivotable hand grip as a stand (i rested it in a 4'' drainage pipe) stabilizes the drill, dampens vibration and eases the strain on the upper limbs. A professional stand for the drill would be ideal, is available but very expensive + needs proper stable surface unless you bolt it to the foundation temporarily. The holes drilled were nice and smooth but slanting downwards toward inside the house, not perfect: likely a side-effect of holding the drill without a pro stand. Once the wrong slope has started (it is not noticeable at that point) is is impossible to correct it In retrospect I should have drilled aiming at at least a +10 degree angle above horizontal to counteract the drill weight effect/muscle fatigue over several minutes of drilling. Also the pilot hole should have been drilled 1 in higher imho. The China-made metric pilot bit that I was sold on AMZ was too loose/wobbly and I finally bought just a slightly larger SAE one in the local hardware store. I drilled a pilot hole first with an SDS bit then inserted the longer pilot bit tip (pushed beforehand inside the drycore bell inner central hole) in a SDS-bit pilot hole.) Once a dry circle was carved .25 in deep, I removed the long pilot bit continuing just with the dry bell.

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.

well made for the price

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.

The CORE DRILL Model 4Z1 2-Speed Concrete Coring Drill is a powerful and reliable tool, ideal for heavy-duty concrete drilling. Its 2-speed motor offers great versatility, providing high torque for large diameter holes and fast performance for smaller ones. The ergonomic design and water-cooling system ensure smooth operation, while the safety clutch adds an extra layer of protection. Though slightly bulky, its performance and durability make it perfect for professional use. Overall, the 4Z1 is a top-notch drill for those seeking precision and efficiency in tough concrete jobs.

100x better than the steel dragon tools drill. the switch can lock but doesn't occur automatically like the sdt drill. plus it has a slower speed for larger bits. I bought this after drilling about 10 holes in 22" thick PA farmhouse walls with the SDT drill. Everything was going OK until the bit bound up on me recently and the drill body spun around on me hitting me incredibly hard in the wrist. I was speechless w. pain. It's a miracle it didn't break my wrist. This drill is so worth the extra money. for anyone new to concrete diamond hole saw drilling I might suggest starting your work with a 1/2" chuck to 5/8-11 or 1-1/4x7 tpi adapter with a normal variable speed drill and a simple garden hose spraying at the hole. This combo doesn't have nearly the same torque and it's a good way to see how you need to hold the drill precisely in line with the axis of the drill to prevent binding and the same near disastrous result I had.

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 *****