Thread milling and tapping have distinct advantages and disadvantages. To help you decide which strategy is best for your part, this article explains the advantages and disadvantages of each.
The Pros and Cons of Tapping
When it comes to speed, tapping is the best option. High-speed tapping centers equipped with a rigid tap can thread holes in less time it would take to thread mill the same holes, allowing for greater productivity. Steel, for example, can have its holes threaded to greater depths thanks to tapping. Check out metric thread taps.
Tapping has a significant drawback in that it requires a different tap for each hole size that needs to be threaded. In addition, having to switch taps for all the different sized holes adds to the cycle time of the process.
The inability to fine-tune thread fit is another drawback of tapping. It is impossible to change the thread size or position after the hole has been tapped. As a final note, rigid taps can’t mill threads onto the outsides of posts or screws because they’re only used to thread holes inside them.
These tools are best suited for tapping through holes rather than blind tapping, threading holes that end within the material. These tools are best suited for tapping through holes rather than blind tap. Because the initial portion of a rigid tap was designed to penetrate rather than thread. In blind tapping, the deepest threads are made with the part of the tool designed to plunge rather than thread. A secondary finishing tool is required to finish these final threads to perfection, resulting in longer cycle times.
In general, tapping is preferable when you need to make many holes with little variation in diameter. More details on metric thread taps.
Pros and cons of thread milling
The ability to precisely control the fit is the primary benefit of thread milling. It is milled at high RPM, and the tool helixes into an already-milled hole, creating a thread-milled hole. A thread size adjustment strategy similar to using an end mill rather than a drill bit to make a hole can be used by the machine operator. If there are tight thread size tolerances or if allowances need to be made for finishing, such as painting, this can be advantageous.
Many hole sizes can be made using a single-thread milling tool. This saves time and money by reducing the number of tool changes. It can also produce right and left-handed threads and large threaded holes in metals (e.g., pipe threads). This reduces the need to purchase a large, rigid tap to thread large holes in the latter’s case.
In addition, the thread mill allows the user to design custom threads without having to invest in expensive and time-consuming custom taps. The thread mill allows maximum threads in a very short distance when machining very shallow blind threads in thin materials.
The only drawback to thread milling is the requirement for a machine with a high-speed spindle capable of speeds up to 60,000 revolutions per minute (RPM).
Find more information, about UN thread taps