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

  1. 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
    Plain Washers Fibre     K1D02 – Download Datasheet

    ISO 7089

    ISO 7089 Plain Washers SS-304 A2 B4iD02 – Download Datasheet
    ISO 7089 Plain Washers SS-316 A4     B6iD02 – Download Datasheet

    Also available in Black Finish on request

  2. 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

  3. 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.

  1. 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

  2. IS 2016 Type BIS 2016 Type B Small OD Plain Washers are available on request.

  3. 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 Datasheet

    Also available in Black Finish on request

  4. 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

  1. 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

    Also available in Black Finish on request

    DIN 9021 Plain Large Washers SS-304 A2 Black U4D03 – Download Datasheet

  2. IS 2016

  3. ISO 7093

    ISO 7093 Plain Large Washers SS-304 A2 B4iD03 – Download Datasheet
    ISO 7093 Plain Large Washers SS-316 A4     B6iD03 – Download Datasheet

    Also available in Black Finish on request

  4. JIS B1256 Large Series

    JIS B1256 Large Series Plain Washers with Larger OD are available on request.

Special Washers and Shim Washers

Penny Washers

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.

Go to the SHIM Rings page.

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.