The simple solution which relies on engineering fundamentals is generally preferable to a more complicated, band-aid solution. Take thermal drilling, also known as flow or friction drilling, as an example: the friction of metal on metal creates heat, which plasticizes metal and allows it to be reshaped. That’s the basic idea behind this interesting little tool and, in many cases, it’s faster, easier and less expensive than installing threaded inserts.
Even if you’re not in the market for a thermal drill, the principle behind thermal drilling just might inspire you to think about how to leverage the even most basic principles of physics to improve your production process.
In the automotive industry, thin-walled parts are common, from hydroformed parts such as a catalytic converter to tubular parts and formed sheet metal. One challenge that arises with these materials comes from installing threaded fasteners, since there isn’t enough material to accept a thread.
One solution has been threaded inserts that can be pressed or welded in, for example. But this technique may be unnecessarily costly in your process. As an alternative, you could be using flow drilling.
Thermal drilling is a friction -based technology that can put tappable holes in thin-walled parts. The process uses a specialized, smooth, fluteless bit at a high speed, using the heat of friction to plasticize and reshape the metal. The metal flows around the hole, creating a side wall up to three times thicker than the original material thickness, making it possible to cut threads with a standard tap. “It’s fairly simple, but it’s useful,” said Rakshesh Patel, Manufacturer Rep for PRP Reps and Suppliers. The company sells Formdrill thermal drilling tools as well as taps and other products.
Formdrill, a manufacturer of thermal drills, has tools for making holes from 6-32 all the way up to an inch and a half, in material thickness of 0.030” up to 0.5” in any malleable material. The holes can be made with a standard off-the-shelf drill press, CNC toolholder, or even with a drilling end effector on a robot. According to Formdrill, the process creates serviceable threads in thin-walled parts much more cost effectively than threaded inserts or other fastening solutions.
For more on engineering and innovation, check out 5 Tips on How to Become an Innovative Engineer.