China Hardwware Accessories ITEM NO: 13040701 Specification:6*110mm Material: Zinc Alloy Processing art: pressed into drill pipe with bit head welded Colour: Silver colour. Function:drilling hole in stone,concrete,marble,cement,etc. High quality 40 chromium-vanadium steel is used as raw material for this drill bit,of which the bit head is welded of YG8 carbide marked different colour.In order to maker the hardness and toughness of the drill,the high temperature heat treatment process is strictly controlled in the production. It is suitable for marble, granite, concrete and other processes.Drill bits require a bit of cemented carbide pressed steel in the steel shank,so when the machine is operating, the drilling speed is faster, working is more stable and chip is easily removed. NOTE: 1.First of all,fix a hole on the wall, check the electric drill plug,make sure it is not opened. Install the drill into the machine. Draw a mark on the location of the drilling, and then turn on the electric drill. move back and forth, so as not to damage the wall. 2.Keep suitable distance at the corner of the junction, appropriately relax the machine,the force will be relatively larger,so the drilling hole will be deeper. 3.Pay attention to the cement wall when moving back and forth, control the speed,keep safe or maybe the drilling is already inside,the machine is still running. It is easy to hurt hands. 4.Finally, the drill must be stably installed.It obviously accurs to increase the friction of the drill and damage the wall if the drill bit is easy to shake.China Hardwware Accessories website:http://www.dingqimaxtool.com/hardwware-accessories/