Engineer Charley Greenwood, with the help of Michael Garnier and machinist Michael Birmingham, added a collar onto a hex cap screw to maximize the surface area and minimize compression in the contact area between the tree and the screw.
12.
I was in the process of washing my hands when he interrupted our conversation _ appropriately enough, we were discussing national politics _ to point out a particularly large cap screw on a portion of plumbing that sprouted from above the facilities.
13.
Male bit drivers are sometimes incorrectly referred to as " sockets ", but are in fact the opposite of a socket, in that bit drivers fit into a socket head cap screw or pipe plug, rather than fit over a male drive head on a nut or bolt as a socket does.
14.
World War II, with its unprecedented push for industrial production of every kind, is probably the event that first put most laypersons in contact with the internal-wrenching hexagon drive . ( " Popular Science " magazine would note in 1946 that " Cap screws and setscrews with heads recessed to take hexagonal-bar wrenches are coming into increasing use . ")
