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Encyclopedia of Fasteners & Hardware Items
 
Courtesy of FastenerMart.com
 
—  WASHERS  —

Belleville Spring Washers

Also Called: Belleville Washers, Conical Washers

Placed under a nut or screw head, these spring action lock washers compress as the fastener is tightened; consequently, outside diameter (OD) and thickness vary with tension. The spring-back force deters loosening. To be effective, Belleville Spring Washers must be installed correctly.

Blind Rivet Backup Washers

Also Called: Backup Washers

Blind rivet washers (backup washers) give extra support when fastening soft materials and in applications that require a larger diameter surface to prevent pull-out.

Fender Washers

Also Called: Large OD Washers

Because of their large outside diameter (OD), Fender Washers offer an extra-wide bearing surface that is useful when working with oversized or irregularly shaped holes and when fastening soft materials that could benefit from increased support.

Fender Washers, Thick

Also Called: Thick Large OD Washers

Thick Fender Washers are flat washers with a large outside diameter (OD), and offer greater thickness than "standard" fender washers. Use them with oversized or irregularly shaped holes or whenever the extra support of a large bearing surface is needed.

Finishing Washers

Also Called: Countersunk Washers, Countersunk Finishing Washers

Finishing Washers, also known as Countersunk Washers, are useful in providing a finished appearance when using flat or oval head screws.

Flat Washers

Also Called: Washers

Flat Washers provide spacing and an increased bearing surface that can be useful when working with oversized or irregular shaped holes.

Flat Washers, Mega Thick

Also Called: Extra Thick Washers

Thicker than thick, Mega Thick Flat Washers range in thickness from 0.110" to 0.336". They work great in those "industrial-sized spacing" applications and as levelers, aside from offering an increased bearing surface.

Flat Washers, Thick

Also Called: Thick Washers

Thick Flat Washers, commonly as spacers, are useful on uneven surfaces as levelers and offer an increased bearing surface like regular flat washers.

Hi-Collar Lock Washers

Also Called: High Collar Lock Washers, High Collar Spring Lock Washers, Spring Washers

These lock washers fit in space-limited areas due to their small outside diameter (OD). Designed for use with smaller head screws like socket head cap screws, Hi-Collar Lock Washers have increased thickness to preserve their locking ability.

Lock Set Washer Pairs

Also Called: Nord-Lock Washer Assembly, Vibration-Resistant Lock Washers

Lock Set Washer Pairs are supplied as an assembly: one pair includes a top and a bottom washer. These reusable washers have wedges on one side, which should be installed interlocked, and radial teeth on the opposite side. When the screw or nut is tightened, the teeth bite into the screw head or nut and the mating material to prevent slippage, while the wedges increase tension to prevent loosening.

Machine Screw Flat Washers

Also Called: Washers

Flat Washers provide spacing and an increased bearing surface. Machine Screw Flat Washers are the smallest type of flat washer because their outside diameter (OD) is just a little more than twice their inside diameter (ID). If you need a larger OD flat washer, choose SAE or, larger still, USS.

SAE Flat Washers

Also Called: SAE Washers, Washers

Flat Washers provide spacing and an increased bearing surface. SAE Flat Washers offer a tighter screw fit and a thinner washer with a smaller outside diameter (OD) than comparably sized USS washers.

Sealing Washers, Metal Backed Neoprene

Also Called: Bonded Sealing Washers

Sealing Washers have a layer of Neoprene bonded to the metal washer that forms a seal that is strong while also being soft and resilient. They can be used with fragile materials and to provide extra cushioning under a nut or the head of a bolt or screw. They are effective in stopping leaks by sealing joints.

Split Lock Washers

Also Called: Spring Washers, Split Ring Lock Washers

These washers, placed under the nut or screw head, compress as the fastener is tightened and the spring-back tension resists loosening. Also, because of their spring-like take-up action, Split Lock Washers can compensate for slight material wear. Heavy Pattern Split Lock Washers offer a larger outside diameter (OD).

Square Plate Washers

Also Called: Square Washers

These Square Plate Washers, which are often used in structural applications, range in size from 2" to 3-1/2" square and in thickness from 1/8" to 3/8".

Square Washers, Beveled

Also Called: Beveled Washers, Square Beveled Washers, Hillside Washers

Used in structural applications, Beveled Square Washers are designed for leveling and shimming purposes.

Structural Washers

Also Called: Structural Bolt Washers

Structural Washers are used in exterior building applications and in construction with A325 bolts, studs and nuts.

Tooth Lock Washers, Countersunk External

Also Called: Countersunk External Lock Washers, Countersunk External Tooth Washers

Countersunk External Tooth Lock Washers create a ratchet action by biting into the screw head and the surface it contacts. They are used with standard (82 degree) Flat and Oval head screws in countersunk holes.

Tooth Lock Washers, External

Also Called: External Lock Washers, External Tooth Washers

External Tooth Lock Washers create a ratchet action by biting into the nut or screw head and the surface it contacts. When used under a screw head, the "external" type require a large head--like Binding, Pan or Round--because the washer teeth must make contact with the head. Since the teeth are on the largest radius, which results in greater twisting resistance, this type is preferred when the greatest locking power is desired.

Tooth Lock Washers, Internal

Also Called: Internal Lock Washers, Internal Tooth Washers

Internal Tooth Lock Washers create a ratchet action by biting into the nut or screw head and the surface it contacts. The "internal" type work best with small screw heads, such as Fillister, and when the teeth--and the surface marks they create--need to be hidden for appearance reasons. Because the teeth must make contact with the mating surface, do not use with oversized holes.

Tooth Lock Washers, Internal-External

Also Called: Internal-External Lock Washers, Internal-External Tooth Washers

Internal-External Tooth Lock Washers create a ratchet action by biting into the nut or screw head and the surface it contacts. Having a larger outside diameter (OD) than "external" and "internal" types, they are used when a larger bearing surface is needed to optimize an electrical connection or because a hole is oversized or irregular. They are also used as an insert between two adjustable pieces to maintain mechanical alignment.

T-Slot Washers

Also Called: Thick Washers

T-Slot Washers are flat washers that have one beveled edge and about the same outside diameter (OD) of a comparably sized SAE washer, but are roughly double the thickness of their SAE washer counterpart. Normally used with T-Slot Bolts but also as spacers because of their thickness, T-Slot Washers are heat treated (when indicated) for added strength.

USS Flat Washers

Also Called: USS Washers, Washers

Flat Washers provide spacing and an increased bearing surface. USS Flat Washers offer a looser screw fit and a thicker washer with a larger outside diameter (OD) than comparably sized SAE washers.

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