Using a Hand Tap

A hand tap is a tool used to cut internal threads into a drilled hole so that a screw or bolt can be directly fastened into material such as aluminum.

Before Tapping

• Drill the correct tap drill size hole (example: #21 for 10-32, #7 for 1/4-20)
• Deburr the hole to remove sharp edges
• Secure the part so it cannot move
• Select the correct tap size

How to Use a Hand Tap

1. Insert the tap into a tap handle
2. Align the tap perpendicular to the hole
3. Apply gentle downward pressure and begin turning clockwise
4. After 1–2 turns, continue turning slowly with steady pressure
5. Every few turns, reverse slightly to break chips
6. Continue until the desired thread depth is reached

Key Technique

• Keep the tap straight at all times
• Do not force the tap if it becomes difficult to turn
• Use cutting fluid when possible to reduce friction and improve thread quality

Common Mistakes

• Starting the tap at an angle
• Forcing the tap (can break it easily)
• Not backing out to clear chips
• Using the wrong tap drill size

Key Idea

A hand tap must be started carefully and kept straight. Most tap failures come from misalignment or forcing the tool instead of allowing it to cut gradually.