I'm looking for a drill with a reduced shank. Which drill should I choose?
Why use a drill with a thin cylindrical (reduced) shank?
A drill with a reduced shank diameter (also called a drill with a cylindrical shank) is often purchased for use in a drill with a smaller clamping capacity, such as a hand drill or a cordless drill.
Drill with reduced shank
Dormer's range includes the A170 with a shaft diameter of ½” or 12.7mm. The Dormer A170 fits in a drill chuck with a maximum diameter of 13mm.
Alternatives to a drill with a reduced shank
Buying a drill with a reduced shank is not the only solution. Most HSS and HSS-Co drills have a relatively soft shank. It can be turned to the desired diameter on the lathe. It is best to use an outside turning chisel with a carbide insert for this. Use the SCLCR/L with CCMT from the Pramet range for this. This external turning chisel is available in several versions.
Back-grinding the shank is also a great alternative to buying a drill with a reduced shank, but a cylindrical grinder is usually not available.
Other alternatives: step drill and conical drill
For drilling a larger hole in thin sheet material, it is better to use a step drill ( Dormer G314 ) or a conical sheet drill ( Dormer M138 ); these have a shank of 6mm - 13mm (depending on the type). A step drill is ideal for drilling sheet steel and thin materials. A conical plate drill is widely used for drilling tinplate, plate, profile and tube (steel), brass, copper, aluminum and stainless steel. Step plate drills are ideal for drilling sheet metal and thin materials. They are suitable for both a hand drill and a stationary drill. With this step drill you can center, drill, deburr and countersink in one operation. The spiral grooves of the step drill guarantee better penetration into the material.
Important Considerations
Reducing the drill shank allows you to use a larger drill bit in a smaller drill bit, but a larger bore requires more machine power. So it is important to make sure that the machine has this power. Overloading the machine can cause damage. Working with drills with a reduced drill shank must therefore be carefully considered, regardless of which solution you choose.
Cutting oil as an aid
The use of sufficient lubricants is essential when machining, even with a hand drill.
Advantages of using cutting oil:
Fast and effective penetration
Cooling effect on the workpiece and tool
Favorable influence on energy consumption and tool and machine life.
In addition, lower friction means less noise pollution.