... 5.delivery on time Type6"(152mm), 6 1/2"(165mm), 8 1/2"(215.9mm), 9 1/2"(241.3mm), 12 1/4"(311mm) , 13 5/8"(346mm ... 537 547 516 536 535available sizes:From 2 7/8 to 26”larger sizes for hole opener bit ,reamer bitadvantagemost favorable price ... , very hard formationButton size (extra features)Button bit,saw teeth1) Y-Conical teeth 2) X-chisel teeth3)K- wide teeth4)G- Gague ...