Drilling holes is a common task in construction, manufacturing, DIY projects, and more. The choice of drilling tool depends on factors like the size of the hole, the material being drilled, and the precision needed. Here we will explore the most common types of drilling tools and the best uses for each.
Drill Bits
Drill bits are the cutting tools that actually make the holes. They come in a range of sizes and designs for different purposes. Common types include:
- Twist drill bits – For drilling in metal, wood, and plastic. Available in all standard sizes.
- Auger bits – For drilling deep holes in wood. Designed to pull themselves into the material.
- Spade bits – For rough holes in wood. Flat blade with a centre point.
- Hole saws – For cutting large diameter holes in wood or metal. A ring with saw teeth on the edge.
- Masonry bits – For drilling in concrete and brick. Carbide tipped for durability.
The bit diameter determines the size of the hole. Common sizes range from tiny 1mm bits up to hole saws over 6 inches in diameter. The material the bit is made from is designed to drill specific materials – softer metals and wood can use high speed steel, while masonry needs tungsten carbide.
Electric Hand Drills
The most common tool used for drilling is the electric hand drill. These drills have a chuck that grips and spins the drill bit. More powerful drills have higher torque to apply more force to the bit. Features to look for include:
- Keyless chuck for quick bit changes
- Variable speed triggers for control
- High torque rating – 500in/lbs is good for household tasks
- Low speed setting – prevents damage when installing fasteners
- Cordless operation for portability
- Li-ion batteries hold charge longer
Cordless drills are the most versatile for mobility, while corded models are capable of heavy duty constant use. Higher voltage 18V models can tackle tough jobs.
Drill Press
A drill press is stationary tool consisting of a mounted drill that travels vertically down on a column. The advantages of a drill press include:
- Accuracy – The workpiece can be clamped in place, allowing precise, straight holes.
- High power – Large motors provide more torque and spindle speeds.
- Depth control – The depth of the hole can be set by adjusting the drill travel.
- Perpendicular holes – The drill travels vertical so holes are straight up and down.
Drill presses are essential in metal fabrication, machine shops and other applications where precision is important. The depth adjustment and 90 degree travel make them far more accurate than a handheld drill.
Cordless Impact Drivers
Impact drivers are power tools that provide a lot of rotational force by hammering as they spin. Much more torque can be generated than a standard drill. Features include:
- Hydraulic hammering mechanism to generate huge torque.
- 1/4″ hex chuck specifically made for driving large fasteners.
- Brushless motors for efficiency and longevity.
- Compact design that fits in tight spaces.
While they can drill holes in wood, impact drivers are really designed for driving large lag bolts, screws, and other fasteners. The hammering action allows them to drive large screws that would stall a normal drill. The high torque rating makes them indispensable for construction applications.
Factors in Choosing a Drill
Consider the following factors when choosing the best drill or drill tool for your application:
Hole Size
The diameter of the required holes determines the type of drill bit and tools required:
- Small holes less than 1/4″ can be drilled with basic hand drills and bits.
- Midsize holes between 1/4″ and 1/2″ need standard drill bits and higher torque drills.
- Large holes over 1/2″ require hole saws, spade bits, or drill presses for control.
Always choose a drill that has the capacity for larger bits than needed. Underpowered drills won’t be effective with big bits.
Material Properties
Certain drill bits and speeds are designed for specific materials:
| Material | Drill Bits | Speed |
|---|---|---|
| Wood | Twist, spade, auger | High speed |
| Metal | Cobalt or Titanium twist | Low speed |
| Masonry | Masonry or carbide | Low speed |
| Plastic | Twist or brad point | Medium speed |
Using the wrong bit or speed can damage the drill or material. Always check the drill specs for appropriate bits and speeds.
Portability vs Precision
The choice between a handheld drill or drill press comes down to the precision needed:
- Cordless hand drills offer flexibility and mobility for jobs like home repairs.
- Drill presses allow precise control and accuracy for metal working, woodworking, etc.
Hand drills are fine for most everyday holes, but drill presses are essential when precision is critical.
Power and Torque Requirements
Heavy duty drilling requires high drill power and torque:
- Small holes in thin materials need low torque drills.
- Large holes and tough materials require 500in/lb+ torque ratings.
- Metal drilling needs lower speed but higher torque.
- Masonry drilling requires rotary hammer function.
Check your drilling application and choose a drill with suitable power specs. Underpowered drills will stall and burn out quickly.
Cordless vs Corded
Both cordless and corded drills have advantages:
- Cordless offers complete mobility but limited runtime.
- Corded gives unlimited use but requires a nearby outlet.
Frequent use or outdoor jobs benefit from cordless flexibility. Corded models provide continuous power for high workload tasks.
Cost Considerations
Drilling tools have a wide range of costs:
- Cheap hand drills under $50 sacrifice durability and power.
- Standard homeowner drills cost $100-$200 with decent capability.
- Heavy duty & commercial models are $200-$500+.
- Industrial grade drill presses run $500+.
Paying more gets you better performance, durability and features. Buy the best drill you can afford for frequent use.
Drilling Tips and Techniques
Proper drilling procedure is key to quick, clean holes:
Prepare the Workpiece
Always start by preparing the material:
- Secure the workpiece in place using clamps or a vise.
- Ensure the drill site is clear of debris and obstructions.
- Start holes with a centre punch to prevent bit wandering.
- Use a backing block behind thin materials like metal sheets.
Proper preparation prevents accidents and helps achieve straight, accurate holes.
Use Appropriate Speed
The drill speed affects cutting performance and bit life:
- Harder materials like metal require slower speeds.
- Softwoods can use high speed for fast drilling.
- Too slow and the bit will rub instead of cut.
- Too fast can damage the material and dull bits prematurely.
Always start at low speed and increase gradually. Consult drill specs to find optimal speeds.
Apply Feeding Pressure
Let the bit cut with light feeding pressure:
- Too much pressure leads to bent bits or broken drill motors.
- Too little pressure prevents the bit from drilling.
- Apply just enough force to keep the hole progressing.
- Ease up if the bit or drill start to strain.
Patience leads to optimum cutting. Aggressive force only causes problems.
Retract Periodically
Regularly back the bit out of the hole:
- Clears chips preventing clogging.
- Allows debris to eject from the hole.
- Cools the bit to prevent overheating.
- Apply cutting oil for lubrication when needed.
Proper chip clearing keeps the hole clean and the bit cutting efficiently.
Drill Perpendicular Holes
Holes should always drill straight and perpendicular:
- Use a drill press for perfect vertical holes.
- For hand drilling, hold the drill square to the surface.
- Rest hands on a brace or table to prevent wobble.
- Take care to start holes straight and level.
Angled holes lead to problems with fasteners and assembly. Only drill straight up and down.
Conclusion
Drilling is made easy with the right tools for the job. Hand drills provide portable convenience for common jobs, while drill presses offer precision and capabilities for heavy tasks. Proper preparation, speed, pressure and technique allow clean, accurate holes in any application. Consider factors like the material, hole size, power needed, and precision required when choosing a drilling tool. With the right drill and good drilling practices, holes can be made quickly and correctly every time.