Tapping

Tapping is the process of cutting internal threads into materials such as metal or plastic. Its purpose is to allow screws or bolts to be precisely fastened and secured within a part, making it an indispensable step for a product's structural integrity and functional integration.

Tapping creates threads in an existing hole (drilling), while drilling is the initial process of creating that hole. The two are often continuous, complementary operations.

Using a hand tool (tap wrench) to manually rotate a tap and cut internal threads. This is suitable for low-volume or special-purpose parts.

Advantages: Low cost, suitable for mold repairs or maintenance.
Disadvantages: Low efficiency, poor quality consistency.

Uses a tapping machine for high-efficiency, batch processing. It is common in hardware and automotive part production lines.

Advantages: Excellent repeatability, high efficiency, consistent quality.
Disadvantages: Requires fixtures, limited by hole diameter and depth range.

Performs high-precision thread cutting within a CNC machining center, controlled by the spindle. It is commonly used for precision machinery, aerospace, and modular components.

Advantages: High precision, suitable for multiple sizes and deep holes.
Disadvantages: High equipment cost, requires professional programming.

This process does not cut material but rather uses pressure to form threads by deforming the material. It is suitable for highly ductile materials (e.g., aluminum, copper, zinc).

Advantages: High thread strength, no chips, fast processing.
Limitations: Requires high accuracy in hole diameter, not suitable for hard materials.

Based on the thread specifications, a pilot hole of the appropriate size is first drilled. The hole diameter must be strictly controlled.

Tapping fluid or an emulsion is used for lubrication to reduce friction on the tap and prevent breakage.

The correct tap tool and speed are selected for cutting. Common specifications include M2~M16 and UNC/UNF series.

Chips must be thoroughly removed, and the thread integrity and depth are inspected. Secondary finishing or test fitting may be performed if necessary.

Uneven pitch / thread stripping: Pilot hole is too small or incorrect speed is used.
Broken tap: Material hardness is too high or insufficient tapping fluid is used.
Off-center hole: Drilling position is misaligned or clamping is unstable.

• Inspecting pilot hole accuracy and concentricity before tapping.
• Setting appropriate speed, feed rate, and fixed tool lifespan cycles.
• Using automated inspection machines to verify thread specifications (e.g., three-wire method, go/no-go gauge).
• Conducting periodic destructive testing and strength verification on batches of parts.

Components like bits, clamps, and mounting plates require numerous screw fastening structures. The tapped hole dimensions and thread depth must be highly consistent. HIROKI offers M4~M12 fully automated tapping machines, producing over a million pieces annually.

For components like brake calipers, chassis brackets, and casing joints, the tapped structure must have high strength and anti-loosening properties. This often involves mechanical tapping and pre-torquing of screws. 

Aluminum alloy structures often require form tapping to improve thread tensile strength and prevent breakage. HIROKI can provide customized tapping torque settings and support assembly lines.

Small terminals, casing plates, and clasp structures require micro-threads from M1.6 to M3. HIROKI has integrated micro-CNC equipment to perform precision tapping on thin-walled parts.

• Automatic Tapping Machines (Vertical/Horizontal)
• CNC Multi-tasking Machines
• Press-in Form Tapping Equipment
• Micro Tapping Workstations

We can process metric (M1.6~M16), imperial (UNC/UNF), fine pitch, and special-spec threads, and provide tolerance analysis.

Tapping operations can be seamlessly integrated with stamping, deburring, and surface finishing processes, reducing handling and cumulative errors and improving overall yield and efficiency.

For parts with multiple holes or complex components, we design multi-station jigs and rotary tapping workstations. This is ideal for mass production and flexible product-switching needs.

Each thread specification has a defined parameter range. Go/no-go gauge standards and testing frequencies are set according to client requirements.

Every batch of tapped parts can be traced back to the raw material, the tap tool used, and the operation time, facilitating quality tracking and anomaly analysis.

For screw-fastened components, we offer a tapping + assembly simulation service to ensure optimal screw insertion torque and control against stripped threads.