the SDS adapter broke off inside my drill. Now the drill must be send for service and I have to buy a new sds adapter.

I hate it

Very disappointed. First time using the set and the weld on the Arbor broke. Swapped to the next smaller bit it then broke the adapter.

Today, I used this kit to drill a 4-1/2" hole through 8-inches of solid concrete. It took 20-minutes. While it wasn't easy, it got the job done very well. Overall, I'm delighted with this kit for the price. The reviewer giving this kit a 1-star admittedly never even tried it which is very unfortunate. I guess he was expecting to pay 70% less yet still get more-expensive, name-brand bits with fancy paint?

The bits themselves are thick-walled and have a lot of diamond surface on very tall segments. I'd guess the diamond segments are double the height vs. a Milwaukee I compared. Of course without testing and analysis, I don't know if they'll last longer or shorter; however, after drilling 8" of solid concrete, I was impressed. I noticed little to no wear, and I ran my Bosch SDS-plus hammer drill (in drill only mode) at full speed the entire time other than to take a rest break. Several time it activated the clutch safety mechanism which any drill doing this work should have. Some paint was removed from the sides of the barrel due to rubbing against concrete, but that's expected with any core bit. Most importantly, the hole quality was excellent.

I am impressed with my first use of this set. The only problem I had was with the tapered pilot bit not cutting very well due to it rotating in its hole. Maybe I needed to seat it better? Regardless, I just used a 3/8" x 10" SDS-plus bit to drill a pilot hole completely through the concrete wall which also confirmed where the hole would be on the other side. Then I chased it with the pilot and core bit combo for 1/2" before removing the pilot to drill just with the core. Because the wall is 8" thick vs. the core drill bit is only 6", at roughly 50% through the wall, I took a hammer and knocked out a plug. This gave me deeper drilling depth still using 6" depth core bit.

For reference, I paid $233 for this kit vs. just one 4-1/2" Milwaukee core bit (no arbor) at Home Depot was $254+tax. Yes, the Milwaukee bit is 14" long which is perfect for complete drill-through in this application; however, for a little less money you get a similar 4-1/2" bit plus four additional core bits (1-1/2", 2", 4", 5"), extension, two arbors (SDS-Plus, hex), a drift, an 8mm tapered pilot bit and a case. The case is actually pretty impressive to carry and hold everything. I'm not sure how heavy-duty/durable it will prove to be, so I don't recommend throwing it around, but on the other hand, it's not cheesy cheap either. Latches are nice and easy to use. So for general use and storage, it should last a very long time.

Conclusively, for the price, this kit is a great deal especially if you're not drilling holes all day, every day. It's a fantastic value for something without the expensive name-brand price that still does a great job in function and form. The only thing possibly missing would be a wrench and a piece of round stock to help remove the core bit from the arbor. I had to go into my service trailer and put a big wrench on the core bit, insert a tapered alignment bar into the arbor and smack it with a hammer. Ultimately, the arbor did unscrew from the core bit--just not easily. Maybe some lube on the threads next time. Overall, I'm very pleased with the purchase and results. I highly recommend this kit if you're not prepared to spend $1,000+ for name-brand bits and thousands more for a core rig.

UPDATE (5/14/15): I've drilled 8 holes of various sizes and just really appreciate the value and quality here. Two 1-1/2" holes took about 10-minutes going through 6" concrete. A 4-1/2" hole took roughly 4-minutes through brick...like a hot knife through butter vs. concrete. I would have preferred not to drill the 1-1/2" holes with a core bit, but realized too late I don't own a 1-1/2" SDS Max bit. My rotary hammer (2" SDS Max Makita) would have been through it within 1-2 minutes at most. After today and thanks to Amazon, a new 4-cutter SDS Max bit is on the way...along with a 1-1/4" and 1-1/8" but these I bought in SDS-Plus as my Bosch rotary hammer drill (1-1/8") is so much lighter and easier to handle. But if you're drilling big holes, frankly, this core kit CAN NOT be beat. 5+ star value and I'm appreciating the well organized and well thought-out case more and more.

Good value but unable to find the appropriate adapter for 1.25" male spindle to 3/4" female coring bit needed for our particular boring rig. The only thing available seems to be a 1.25" to 5/8" adapter.