Among one of the most significant tools in machining, are helical taps. With their ability to create threads on a wide range of materials, including plastic and metal, these cutting tools serve as an imperative for any machinist. The spiral design from which helical taps derive their name facilitates a smooth and consistent motion while cutting into materials.
Helical taps can be found in various types, each specifically geared towards specific applications. Straight-fluted, spiral-fluted, and gun taps rank amongst some of the most commonly used forms of helical taps available. Of all the variants available commercially, straight-fluted taps boast the simplest form – wherein chips are released through a straight channel. Characterized by a helical groove, spiral-fluted taps aid in chip-breaking and removal from the drilled hole. Ideal for soft materials, gun taps feature high rake angles that reduce cutting force.
To suit various needs, helical taps come in different materials such as cobalt, carbide or high-speed steel. While high-speed steel remains the most common because of its easy sharpening and durability, cobalt is recommended for harder materials and larger production runs. Along with their high cost, carbide taps boast the impressive capacity to outlast other materials by a factor of ten when utilized appropriately. To ensure optimal results when utilizing helical taps, the size and pitch must be carefully considered.
Size corresponds to tap diameter whereas pitch refers to thread distance. True to its name, pitch is gauged by thread count measured in threads per inch (TPI) or millimeter (TPM). The seamless matching of tap size and pitch with both threaded materials and employed tools is fundamental for successful threading operations. In order to extend the lifespan of helical taps, appropriate maintenance practices must be followed.
Regular cleaning and oiling are crucial for their upkeep, as is sharpening them periodically to eliminate accumulated chips and debris in the flutes. The accumulation of such materials can potentially compromise the tap’s integrity and render it ineffective or unusable. To maximize its durability, lubrication with oil is also recommended to minimize friction that can increase wear and damage over time. Helical taps offer an array of benefits that make them a must-have tool in both the hobbyist and professional machinist’s toolbox. These advantages include the ability to provide smooth, ongoing cutting operations and create precise threads across various materials.
Utilizing the correct size and pitch for each job and routinely maintaining these tools can ensure long-term dependable service.