1)Multi-purpose drill bits 

Made by cobalt and tungsten carbide tip, Special degrees of carbide to enable well centered drilling, the chrome vanadium steel shank provides extra hardness and torque force

Application: Masonry,Ceramic tile,Concrete,Brick,Fiberglass/Plexiglass/Glass,Cast metals,Hardened steel,Granite,Marble,Woods,Plastics,Eliminates etc. Sizes are from 3mm-25mm (1/8"-1")

Carbide Tip of multi-purpose drill bits in black flute

2)Picture of multi-purpose drill bits 

3)reduced shank of multi-purpose drill bits 

4)Skinned card packing for multi-purpose drill bits 

5)Metric sizes of multi-purpose drill bits

6)Inch sizes for multi-purpose drill bits

7) Drilling Instruction

Please follow the speed and technique instructions below

Hardened Steel and Iron            2000—4000 RPM (Lubricant)

Masonry/Concrete                 2000—4000 RPM (Percussion)

Stainless Steel                    1500—2500 RPM (Coolant)

Glass/Tile/Granite                  300—600 RPM

Plastic and Laminates               300—600 RPM

Solid Surface Materials              300—600 RPM

Wood and Composite                500—1000 RPM