Thread tapping in aluminum extrusion refers to the process of creating threaded holes in aluminum extrusions. Here are the key points for tapping aluminum extrusions, tailored for an English-speaking audience:
- Selecting the Right Tap: For tapping aluminum extrusions, it is recommended to use extrusion taps. These taps are suitable for materials with plasticity, such as aluminum, copper, zinc, brass, and low-carbon steel. Extrusion taps form threads by plastically deforming the material within the bottom hole without generating chips, making them ideal for blind hole threading and ensuring high thread quality.
- Tapping Methods: Tapping can be divided into cutting taps and extrusion taps. Cutting taps create internal threads by removing metal, whereas extrusion taps form internal threads by extruding the metal within the hole to fill the tap flutes.
- Tapping Operation: The main steps for tapping an aluminum plate include preparation, pre-drilling, tap selection, tapping operation, and subsequent cleaning. Pre-drilling is an essential step before tapping an aluminum plate, helping to accurately control the position and depth of tapping while reducing resistance during the process.
- Tapping Considerations: The torque required for tapping is 2-3 times greater than that for cutting taps, so it is necessary to confirm machine power and ensure stable workpiece clamping during the process. The tolerance of the bottom hole diameter should be controlled within 5% of the pitch, requiring stricter management compared to cutting taps.
- Tap Coating: Adding the appropriate coating can significantly increase the service life of taps. The domestic coating market varies greatly, with price differences reaching up to tenfold and performance differences significant. The best coating manufacturer and type should be chosen based on production and processing needs.
- Tapping Efficiency and Thread Strength: Threads formed by extrusion taps have approximately a 30% increase in strength and stable precision. The mother thread forms smoothly with good surface roughness and minimal deviation in effective diameter.
- Tapping Speed and Feed: The tapping process requires a strict proportional relationship between spindle speed and feed rate. Programming should be based on spindle speed to calculate the feed rate (Feed rate = Spindle speed × Lead pitch).
By understanding these points, it is clear that tapping aluminum extrusions is a process that requires precise operation and the right tool selection to ensure thread quality and strength.
