I also found it necessary to substitute the 82-degree slotted
fillister screw with an 82-degree socket head screw of same length.
This 1/4" slotted screw is threaded at the bottom of the lower tang for a
fillister head screw.
Pads are normally attached with Phillips screws but some are attached with the square, slotted type, either
fillister or round head.
There are machine screws, metric screws, wood screws, countersunk screws; with square-drive heads and slotted heads, torx, Phillips, pan head, button head, round head,
fillister head, with high-low, self tapping, wood, metal threads and many more I can't think of right now, but you get the point.
This includes an 8-40 taper and bottoming tap, numbers 28 and 19 wire gauge drills, an 8-40
Fillister counterbore and a dozen each of 1/4-inch and 3/8-inch socket head screws.
Those most commonly used include the slotted
Fillister head, Allen or socket head and the more recent addition of the Torx head.
Let's say it is a
fillister head, head thickness unknown, with a length overall of 3/4 inch and with 1/8 inch cut to 5/40.
The photoreactor contained two hollow
fillisters at the top fixture and the bottom fixture, respectively.
A hundred years ago a carpenter's tool chest typically would have contained dozens of varieties of planes, and a typical hardware catalogue would list hundreds of varieties (astragals,
fillisters, snipe bills, ogees, Grecian ovolos), each one adapted to a highly specialized purpose.