Cast in many industrial products have long been used mortgages (anchor) bolts with special heads, such that not only pull, but rotate can’t.
With the advent of high strength composite self-hardening compositions that bolt you can “lay” in the body of the finished product (plastic or metal) and making it pre-nest, and then simonaityte.
Recommend to read
UNIVERSAL INDICATOR
Two LEDs with different color (e.g., red and green), you can build a simple indicator for voltages from 4.5 to 220 V. It is also able to determine the polarity of the source in the range...
RELIABLE CONTACT
About how important proper contact of battery terminals, know of any motorist. But sometimes around the lead pin of the battery cracks, through which the electrolyte or its fumes get to...
