1. Phoenix Specialty What's With Metal Washers?
Phoenix Specialty What's With Metal Washers? Washers help threaded fasteners in many ways,
most notably by effectively distributing and maintaining clamp load, and preventing fastener
movement or corrosion.
To the general public, a washer is just a cheap metal disc that keeps screws, bolts, and nuts tight.
But to manufacturers, a washer is a vital fastening component, specially designed to perform
unique functions and ensure a reliable bolted joint.
Every year manufacturers use billions of washers, which are made of various materials and come
in many thicknesses, diameters, finishes and grades. Suppliers estimate that manufacturers use
about two-thirds of their washers for assembly applications and the remainder for maintenance of
their production equipment.
Most washers are used to distribute the clamp load applied by a threaded fastener. Other washers
are designed to help keep a fastener locked in place or insulated, such as from moisture and
electricity. Still others are placed on shafts to function as a spacer or bearing within an assembly.
When used properly, washers can truly benefit product assembly, says Phoenix Specialty When
used improperly, unnecessarily, or to cover up design or production flaws, washers may provide
no benefit at all, while adding to the cost of a project.
Standard Types
According to the Precision Metal forming Association, there are six standard types of washers:
flat, shoulder, tab, lock, countersunk and spring. All of these washers are used with fasteners.
Flat washers are the most popular type and come in many configurations. They feature flat top
and bottom surfaces, and an inner and outer shape that may be round, square, rectangular or
hexagonal. The washer's main purpose is to distribute fastener load and reduce heat and friction
during installation.
Phoenix Specialty, says flat washers can also be used as a spacer. For example, Phoenix
Specialty, knows of one manufacturer that uses a flat washer between two surfaces within the
pivot point of a robot arm to prevent them from rubbing against each other.
This washer is hard enough to withstand the pressure, but thin enough to not hinder motion, The
washer is Teflon and only 0.05- or 0.062-inch thick.
Phoenix Specialty says flat washers can be further divided into many subcategories, based on
either shape or a specific industry standard (USS or SAE). The shape categories encompass
fender, dock, structural and thru-hard washers.