plug taps

Plug taps are essential tools for creating internal threads in various materials. They are characterized by their semi-tapered design, enabling a smooth start and efficient thread cutting. This guide explores the uses, types, and best practices for using plug taps, empowering you to choose the right tool for your threading needs and achieve professional results.What are Plug Taps?A plug tap, also known as a second tap, is a type of hand tap used in metalworking, woodworking, and other industries for creating internal threads in a pre-drilled hole. It's designed as an intermediate tap between a taper tap (for starting the thread) and a bottoming tap (for finishing the thread to the bottom of a blind hole).Key Features of Plug Taps: Semi-Tapered Design: Plug taps feature a moderate taper of 3-5 threads, making them easier to start straight and cut threads smoothly. Thread Creation: Used after the taper tap, the plug tap cuts a more complete thread profile. Versatility: Suitable for threading through holes and partially threading blind holes.Types of Plug TapsPlug taps are available in various materials, sizes, and thread types to accommodate different applications. Here are some common classifications:By Material: High-Speed Steel (HSS): Most common type, suitable for general-purpose threading in steel, aluminum, and plastics. Cobalt HSS: Contains cobalt for increased heat resistance and hardness, ideal for harder materials like stainless steel. Carbide: Offers superior wear resistance and hardness for threading abrasive materials and high-volume production.By Thread Type: National Coarse (NC): Standard thread for general-purpose applications. National Fine (NF): Provides greater holding power and finer adjustments. Metric Coarse (M): Metric standard thread. Metric Fine (MF): Metric fine thread. National Pipe Taper (NPT): Tapered thread for creating leak-proof joints in pipes.By Coating: Bright Finish: No coating, suitable for general-purpose use. Titanium Nitride (TiN): Provides increased hardness and wear resistance. Titanium Carbonitride (TiCN): Offers even greater hardness and wear resistance than TiN. Black Oxide: Improves lubricity and reduces friction.When to Use a Plug TapPlug taps are typically used in a sequence with other taps to create precise and functional threads. Here's a typical scenario: Taper Tap: First, a taper tap is used to start the thread. The tapered design allows for easy alignment and gradual cutting. Plug Tap: Next, the plug tap is used to continue the thread-cutting process, creating a more complete thread profile. Bottoming Tap: Finally, a bottoming tap is used to cut threads to the bottom of a blind hole, ensuring maximum thread engagement.How to Use a Plug Tap: A Step-by-Step GuideFollow these steps to use a plug tap effectively: Prepare the Workpiece: Drill a hole to the correct tap drill size. Consult a tap drill chart for the appropriate size based on the thread size and pitch. Secure the Workpiece: Secure the workpiece in a vise or other suitable holding device to prevent movement during tapping. Start the Thread: Insert a taper tap into the hole and turn it clockwise, applying downward pressure. Ensure the tap is aligned straight to avoid cross-threading. Continue with the Plug Tap: After the taper tap, use the plug tap to deepen and refine the thread. Apply cutting fluid to lubricate the tap and remove chips. Reverse and Clean: After each full turn, reverse the tap slightly to break the chips and prevent binding. Clean the chips from the tap and hole frequently. Finish with a Bottoming Tap (if needed): If threading a blind hole, use a bottoming tap to finish the threads at the bottom of the hole. Test the Thread: After tapping, test the thread with a screw or bolt to ensure proper fit and function.Tips for Successful Tapping with Plug Taps Use Cutting Fluid: Apply cutting fluid to lubricate the tap and remove chips. Different cutting fluids are available for various materials. Maintain Alignment: Ensure the tap is aligned straight to avoid cross-threading. Use a tapping square or guide to help maintain alignment. Apply Even Pressure: Apply even pressure while turning the tap. Avoid excessive force, which can break the tap. Break Chips: Reverse the tap slightly after each full turn to break the chips and prevent binding. Clean Frequently: Clean the chips from the tap and hole frequently to prevent clogging and ensure smooth cutting. Use the Right Tap for the Material: Select the appropriate tap material and coating for the material being threaded. HSS taps are suitable for general-purpose use, while cobalt HSS and carbide taps are better for harder materials. Consider Thread Engagement: Ensure sufficient thread engagement for the application. The length of thread engagement should be at least 1 to 1.5 times the diameter of the screw or bolt.Choosing the Right Plug Tap for Your ProjectSelecting the correct plug tap depends on several factors, including the material being threaded, the thread type, and the application. Here's a table summarizing the key considerations: Factor Considerations Example Material Hardness, abrasiveness, heat resistance HSS for aluminum, Cobalt HSS for stainless steel Thread Type NC, NF, Metric, NPT NPT for pipe fittings Hole Type Through hole, blind hole Use a bottoming tap after plug tap for blind holes Coating Wear resistance, lubricity TiN for general-purpose, Black Oxide for lubricity Where to Buy Plug TapsYou can find plug taps at various industrial supply stores, hardware stores, and online retailers. Consider purchasing from reputable suppliers like Wayleading Tools, known for their quality tools and reliable service. When buying, pay attention to the specifications of the tap to ensure it meets your project's requirements.ConclusionPlug taps are indispensable tools for creating internal threads. Understanding their features, types, and proper usage techniques is crucial for achieving accurate and reliable results. By following the guidelines outlined in this comprehensive guide, you can confidently select and use plug taps to create high-quality threads in a variety of materials. Remember to choose the correct tap for your material and application. At Wayleading Tools, we are committed to providing the best tools for all your threading needs.