🛠️ Types of Drills, Description & Drilling Machines
Drilling is a common task for electricians — whether it's for fixing panels, mounting switchboards, or running wires through walls and metal plates. Let's understand the tools used for this job.
🔩 What is Drilling?
Drilling is the process of making a round hole in a solid material using a rotating drill bit.
🧰 1. Types of Drills (Tools)
🔹 Twist Drill
📄 Description: Most common drill bit, spiral-shaped
📌 Use: For general purpose drilling in metal, plastic, and wood
🔹 Flat Drill
📄 Description: A flat cutting edge with no flutes
📌 Use: Used in earlier days for drilling soft metals
🔹 Center Drill
📄 Description: Short and stiff drill used to make a starting hole
📌 Use: Prevents regular drill bits from slipping
🔹 Countersink Drill
📄 Description: Cone-shaped drill
📌 Use: For making a recess so screw heads can sit flush with the surface
🔹 Auger Drill
📄 Description: Spiral-shaped drill with screw tip
📌 Use: Mainly used for wood drilling
🧰 2. Types of Drilling Machines
🔹 Hand Drill (Manual)
🔋 Power: No electricity needed
🖐️ Use: For light work in soft materials
🧰 Description: Operated by rotating handle manually
🔹 Electric Hand Drill
⚡ Power: Operated by electric motor
📌 Use: Light to medium work, wall drilling, box fitting
🧰 Easy to carry and used by electricians on site
🔹 Cordless Drill
🔋 Power: Battery-operated
🧳 Use: Portable and ideal for on-the-go tasks
🪛 Some models come with screw-driving features
🔹 Bench Drilling Machine
🪛 Mounted on a table or bench
📏 For precise drilling of small to medium parts
⚙️ Often used in workshops
🔹 Pillar Drilling Machine
🗼 Larger version of bench drill, stands on the floor
📌 Used for bigger components
🧱 More stable and powerful than hand drills
🔹 Radial Drilling Machine
📐 Arm can move in radial direction
📌 Suitable for large jobs where the hole position varies
⚙️ Used in factories
📏 Drill Bit Specifications
| Feature | Description |
|---|---|
| 🔧 Diameter | Common sizes: 1 mm to 13 mm (for electricians) |
| 🔩 Material | High-speed steel (HSS) or Carbide |
| ⚙️ Angle | Cutting angle: 118° for general purpose |
⚠️ Safety Tips While Drilling
👓 Always wear safety goggles
🧤 Wear gloves, but avoid loose clothes
🛑 Disconnect power before changing bits
📏 Mark the hole location clearly before drilling
🔩 Clamp the workpiece to prevent movement
🧯 Keep fire extinguisher nearby for emergencies
🧠 Summary Table
| Tool / Machine | Use | Power |
|---|---|---|
| Twist Drill | General purpose hole drilling | Manual + Electric |
| Hand Drill | Soft materials | Manual |
| Electric Hand Drill | Wall & metal drilling | Electric |
| Cordless Drill | Mobile drilling | Battery |
| Bench Drill | Accurate small jobs | Electric |
| Pillar Drill | Heavy duty drilling | Electric |
| Radial Drill | Flexible large work | Electric |
💡 Conclusion
Drilling is a vital part of electrical installations. Using the right type of drill and machine improves speed, safety, and precision.
🔧 Tip: Always start with a center punch to keep your drill steady!