Spider Washers, strictly speaking, are not fasteners; however, if you are fabricating light fixtures that have shades, you need Spider Washers.Spider Washers are the central hub of the framework for any lampshade. The standard size Spider Washer has an outside diameter of 7/8", slips 1/8" pipe in the center, and has a number of holes for 1/8" spokes. There are 3 in the picture above.
If you are fabricating shade frames for a wrought lamp or custom light fixture, the chances are good that you will need a larger Spider Washer than that. With that in mind, we offer Spider Washers that have an outside diameter of 1-7/8", and slip 1/2" pipe. We offer them with a choice of 3, 4, 6, or 8 spoke holes. Our spoke holes are 3/16" in diameter, and are 3/8" deep. They do not go all the way through to the center, so as to prevent the spokes from interfering with the center support pipe.
The method of attachment can be by staking, or by welding, as our Spider Washers are machined from c1018 steel.
The spokes in the picture are only for illustration; Spider Washers do not come with spokes, of course.
It is expensive to machine only one or two Spider Washers, so we have them machined in larger quantities, to make them affordable to you, the fabricator.
How many spokes should your shade frame have? Consider the size of the shade assembly, both diameter and height, and the fabric used. Is the fabric cloth, fiberglas, or mica? Is there a diffuser? The larger the diameter of the shade and the heavier the fabric, the more spokes you should use. The table below is intended to be helpful, but certainly not definitive. Your choice of Spider Washers are ultimately just that, your choice.
