Steve serves as Senior Editor of Machine Design. He has 23 years of service and has a B.S. Biomedical Engineering from Steve was a Flight officer in the U.S. Navy. He is currently responsible for areas such as aerospace and medical.
Self-tapping screws are usually drilled into pre-made holes (pilot holes) in metals, such as zinc, aluminum, and bronze and its alloys, as well as plastics and resin-impregnated plywood. Here are 15 that you should know.
The U.S. should commit to a 20- to 30-year program that puts an occupied base on the moon, a construction-centric space station working in orbit, humans on Mars, or something equally grand and inspirational.
When engineers need to make curved or bent pieces of sheet metal, they use company-written tables, rules of thumb, and guesstimates to determine the length of straight stock needed for bending into a precisely measures curved part. But these methods are unavailable to some engineers.
Tamper-resistant or security fasteners are often used to prevent unauthorized entry. They are often non-removable or require a special tool to remove them. Higher-quality tamper-proof fasteners have hardened heads, making it difficult to form a new drive slot with a file.
A major cause of failures in metal fasteners is electrochemical corrosion (rust), or so-called galvanic action. Engineers and designers alike can greatly reduce this type of corrosion by specifying fasteners made of the proper materials or with the right coatings.