Plain Washers
Plain Washers
A plain washer is a thin plate, which is most commonly has a disk-shape with a hole in middle. It is widely used to distribute the load of a threaded fastener. Plain washers are used to provide a larger bearing surface where screws, bolts and nuts come in contact with the bearing surfaces.
The main role of flat washers is to increase the size of a screw’s bearing surface area, and reduce the surface pressure applied on the fastened object.
Looseness can result when the bearing surface sinks under the surface pressure, so using a flat washer to reduce the surface pressure is very effective.
This is especially crucial if the contact area between a screw’s bearing surface and the object being fastened is small when fastening to a slot, for instance, or if the object being fastened is made of soft material such as aluminum or resin.
NOMENCLATURE
d1 Inside diameter
d2 Outside diameter
s Thickness.
Incidentally, since flat washers are basically manufactured by pressing, one side has rounded corners and one side has burrs, as shown in the figure.
There is no fixed rule about which side goes up and which goes down, but given the issue of bearing surface pressure mentioned above, it’s more effective to put the burred side facing down.
However, since the burrs could mark the surface of the fastened object during tightening, it would be better to put the rounded side down if you want to avoid plating peeling.
There is a large range available to suit every application.
Plain Washers – Normal Series
The normal series is available as per the following standards
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DIN 125
DIN 125 Plain Washers SS-304 A2 B4D02 – Download Datasheet
DIN 125 Plain Washers SS-316 A4 B6D02 – Download Datasheet
DIN 125 Plain Washers SS-304 A2 Black U4D02 – Download Datasheet
DIN 125 Plain Washers SS-316 A4 Black U6D02 – Download Datasheet
DIN 125 Plain Washers Titanium Gr2 R1D02 – Download Datasheet
DIN 125 Plain Washers Nylon K3D02 – Download Datasheet
DIN 125 Plain Washers Brass D4D02 – Download Datasheet
Plain Washers Fibre K1D02 – Download DatasheetISO 7089
ISO 7089 Plain Washers SS-304 A2 B4iD02 – Download Datasheet
ISO 7089 Plain Washers SS-316 A4 B6iD02 – Download DatasheetAlso available in Black Finish on request
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IS 2016 Type A
IS 2016 Plain Washers SS-304 A2 B4D01 – Download Datasheet
IS 2016 Plain Washers SS-316 A4 B6D01 – Download Datasheet
IS 2016 Plain Washers Mild Steel – Zinc White A2D01 – Download Datasheet
IS 2016 Plain Washers Mild Steel – Zinc Yellow A3D01 – Download Datasheet
Plain Washers Hylam K6D01 – Download Datasheet
Also available in Black Finish on request
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JIS B1256 Normal Series
JIS B1256 Normal Series Plain Washers are available on request.
Plain Washers – Smaller OD
Smaller Outer Diameter washers for Machine Screws are available as per the following standards.
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DIN 433
DIN 433 Plain Washers Small OD SS-304 A2 B4D10 – Download Datasheet
DIN 433 Plain Washers Small OD SS-316 A4 B6D10 – Download Datasheet
DIN 433 Plain Washers Small OD SS-304 A2 Black U4D10 – Download Datasheet
DIN 433 Plain Washers Small OD SS-316 A4 Black U6D10 – Download Datasheet
- IS 2016 Type B
IS 2016 Type B Small OD Plain Washers are available on request. -
ISO 7092
ISO 7092 Plain Washers Small OD SS-304 A2 B4iD10 – Download Datasheet
ISO 7092 Plain Washers Small OD SS-316 A4 B6iD10 – Download DatasheetAlso available in Black Finish on request
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JIS B1256 Small Series
JIS B1256 Small Series Plain Washers with Smaller OD are available on request.
Plain Washers – Larger OD
Larger OD washers are used for irregular holes, softer materials and larger holes.
They are sometimes referred to as “Fender Washers” and distribute the load over a larger area making them useful for materials such as wood and plastics.
Large OD are available as per the following standards
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DIN 9021
DIN 9021 Plain Large Washers SS-304 A2 B4D03 – Download Datasheet
DIN 9021 Plain Large Washers SS-316 A4 B6D03 – Download Datasheet
DIN 9021 Plain Large Washers Mild Steel – Zinc White A2D03 – Download Datasheet
DIN 9021 Plain Large Washers Mild Steel – Zinc Yellow A3D03 – Download Datasheet
DIN 9021 Plain Large Washers Nylon K3D03 – Download Datasheet
DIN 9021 Plain Large Washers Titanium GR2 R1D03 – Download DatasheetAlso available in Black Finish on request
DIN 9021 Plain Large Washers SS-304 A2 Black U4D03 – Download Datasheet
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IS 2016
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ISO 7093
ISO 7093 Plain Large Washers SS-304 A2 B4iD03 – Download Datasheet
ISO 7093 Plain Large Washers SS-316 A4 B6iD03 – Download DatasheetAlso available in Black Finish on request
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JIS B1256 Large Series
JIS B1256 Large Series Plain Washers with Larger OD are available on request.
Special Washers and Shim Washers
Plain Washers as per NF-E25-513 and NF-E25-514
Special dimension plain washers as per Afnor Standards are also available as per NFE 25-513 and NFE 25-514.
These have alternate dimensions and are useful for special applications.
These are available in AISI 304 and AISI 316.
NFE 25-513/514 Plain Washers SS-304 A2 – Download Datasheet
NFE 25-513/514 Plain Washers SS-316 A4 – Download Datasheet
Penny Washers
Special dimensions are also available under our Penny Washer Series.
These have a larger outer diameter and are suitable for softer materials.
These are available in AISI 304 and AISI 316.
Penny Washers SS-304 A2 B4D49 – Download Datasheet
Penny Washers SS-316 A4 B6D49 – Download Datasheet
Turned Cup Washers
We also have Turned Cup Washer available in stock.
Cup washers are used in conjunction with countersunk head screws.
These are available in AISI 303 and AISI 316.
Turned Cup Washers SS-303 B3D46 – Download Datasheet
Turned Cup Washers SS-316 A4 B6D46 – Download Datasheet
Stamped Cup Washers
We also have Stamped Cup Washer available in stock.
Cup washers are used in conjunction with countersunk head screws.
These are available in AISI 304 and AISI 316.
Stamped Cup Washers SS-304 A2 B4D51 – Download Datasheet
Stamped Cup Washers SS-316 A4 B6D51 – Download Datasheet
Metal Bonded Sealing Washers
We also have Metal Bonded Washer available in stock.
These washers are useful for sealing applications.
Commonly used in roofing, they help with waterproofing.
These are available in AISI 304 with EPDM combination.
Metal Bonded Sealing Washers SS-304 A2 EPDM J2D50 – Download Datasheet
Thick Washers – DIN 7349
Thick Washers are used for bolts with heavy type spring pins.
DIN 7349 Thick Washers SS-304 A2 B4D04 – Download Datasheet
Shim Washers
We have a range of Shim washers or Shim Rings as per DIN 988.
Shim rings are flat washers used in combination when axial clearance must be offset.
This could be on a shaft where there is a locking ring/bearing, between which clearance must be offset.
By combining washers of different thicknesses you can precisely offset the clearance.
We ensure that every batch confirms correctly to the relevant standard and material grade.
Washers Materials
They are available in the following materials.
Mild Steel – Natural Finish, Zinc Plated and Nickel Plated.
Stainless Steel – AISI 304 and AISI 316 (Also available in Black Coating SS-304 and SS-316)
Titanium – Grade 2
Nylon
Hylam
Fibre
Nylon Washers
Nylon Washers are useful for weight saving and insulation applications.
DIN 125 Plain Washers Nylon K3D02 – Download Datasheet
DIN 9021 Plain Large Washers Nylon K3D03 – Download Datasheet
Plain Washer Hardness
Class 100 HV : Minimum HV 140 (Rockwell B 56.2 minimum). Suitable for hexagon bolts and screws of product grade C in property classes up to and including 6.8; hexagon nuts of product grade C in property classes up to and including 6; case-hardened thread rolling screws
Class 140 HV : Minimum HV 140 (Rockwell B 75 minimum). Useful for majority of industrial applications including stainless steel assemblies.
Class 200 HV : Minimum HV 200 (Rockwell B 91.5 – C 29.8). Useful for higher demands in manufacturing, maintenance and repair.
Class 300 HV : Minimum HV 300 (Rockwell C 29.8- 40.8). Hardened and tempered. Best suited for use with through hardened screws, bolts and nuts.
USAGE NOTES.
Material Selection.
For normal conditions, SS-304 A2 is suitable
For increased corrosion resistance and suitability for marine applications SS-316 A4 is suitable.
For High Temperature applications SS-316Ti is suitable.
For weight saving, high corrosion resistance and aerospace applications Titanium is suitable.