ReltonGRT-K5 5-Piece Groo-V Tip Bit Kit

I bought these after a shower upgrade. I had very hard thick porcelain tile installed and watched the contractor spend a lot of time drilling holes for the grab bars. His team was very careful and mindful of the possibility of cracking a tile and hole diameter size. The tiles were 4 ft high and 8" wide. They used water spray and went thru a number of Bosch bits that seemed to dull even though they cooled the bits and drilled at a slow speed to accomplish a great job. But I was completely baffled when the shower door contractor drilled 2 less holes and did it in less than 1 minute per hole compared to almost 45 mins. per hole for the grab bars. I did explain to him about the hardness of the tile and the difficulty the tile contractor had but he seem to have no concerns about drilling the tile. He did a great job too but before he left I had to ask him to show me his bits (the Relton Groom-V) plus he explained he used the Relton bits exclusively for installing the hinges and framing for the glass shower doors. Kudos to Relton, the extra cost far outweighs the time spent drilling into hard porcelain tile it seems. No offense to other brands, I did not do any drilling, I am only reporting what I witnessed. The R.G. V-bits were quick and efficient.

They work great for tile, they even work on porcelain tile with acceptable life if you use water. best feature is they stay on target and you don't need a center punch before drilling.

These are the BEST!! Contractor Grade!!!!!

I used them on a porcelain tile and theyWorked alright. I will try them on graniteNext and see I how the work.

Great drill bits...expensive but well worth it.

These were recommended by a friend that installs glass showers, they work well.

Awesome