Stainless Steel Washer

The main function of a SS Washer is to distribute the stress exerted by both the nut or bolt evenly over the part it has been secured to. This action aids in reduction of the chance of damage. Moreover, the 316 SS Flat Washer also provides a smooth surface for the nut or bolt to bear on.

Stainless Steel Washer

A result of the smooth surface of the AISI 304 Washer is what makes it less likely to become loose as a result of an uneven surface of the fastener. Square shaped, SS Beveled Washer is designed in a manner where one bearing surface is flat, while the other is angled in a slope. Designed for levelling and shimming purposes, they are used in structural applications and are particularly common while bolting through the flanges of I-beams. SS Internal Tooth Lock Washers absorb shock and vibration and are designed with the intention of preventing loosening of a nut or bolt with the strut action set up by the teeth. While the function of SS External Tooth Lock Washers is similar to its internal counterpart, the teeth extend radially outward and bite into the bearing surface. The sharp edges of the SS split washer claws into the mounting surface and the nut in order to prevent counter-clockwise rotation. While the SS Fender Washers may look similar to the regular washers, the outer diameter of a fender washer is much wider than the SS Flat Washer, thus enabling easy distribution of weight.

 

Specification List of Stainless Steel Washer

Stainless Steel Washer Standard Specifications American Society of Mechanical Engineers SA 193
Standard of SS Split Washer American Society for Testing and Materials, Deutsches Institut, British Standards
Length of 304 SS Flat Washers M02 to M33
Size of SS Spring Washer in Inches 0.11 Inch to 7.87 Inch

Dimensions Schedule of Stainless Steel Split Washer

SS SCREW SIZE I.D. O.D. THICKNESS
M 1.6 1.7 4 0.3
M 1.8 2 5 0.3
M 2 2.2 5 0.3
  M 2.2 2.4 6 0.5
M 2.5 2.7 6.5 0.5
M 3 3.2 7 0.5
M 3.5 3.7 8 0.8
M 4 4.3 9 0.8
M 4.5 4.8 10 1
M 5 5.3 10 1
M 6 6.4 12.5 1.6
M 7 7.4 14 1.6
M 8 8.4 17 1.6
M 10 10.5 21 2
M 12 13 24 2.5
M 14 15 28 2.5
M 16 17 30 3
M 18 19 34 3
M 20 21 37 3
M 22 23 39 3
M 24 25 44 4
M 27 28 50 4
M 30 31 56 4
M 33 34 60 5
M 36 37 66 5
M 39 40 72 6
M 42 43 78 7
M 45 46 85 7
M 48 50 92 8
M 52 54 98 8
M 56 58 105 9
M 60 62 110 9
M 64 66 115 9
M 68 70 120 10
M 72 74 125 10

304 Stainless Steel Flat Washers Size In Inch

For Screw
Nominal Size
Hole Diameter Outside Diameter Washer Thickness
M1.6 1.7 4 0.3
M2 2.2 5 0.3
M2.5 2.7 6 0.5
M2.6 2.8 7 0.5
M3 3.2 7 0.5
M3.5 3.7 8 0.5
M4 4.3 9 0.8
M5 5.3 10 1
M6 6.4 12 1.6
M7 7.4 14 1.6
M8 8.4 16 1.6
M10 10.5 20 2
M12 13 24 2.5
M14 15 28 2.5
M16 17 30 3
M18 19 34 3
M20 21 37 3
M22 23 39 3
M24 25 44 4
M27 28 50 4
M30 31 56 4
M33 34 60 5
M36 37 66 5
M39 40 72 6
M42 43 78 7
M45 46 85 7
M48 50 92 8
M52 54 98 8
M56 58 105 9

Why use washer under bolt heads?

A washer is a hardware device that is a thin plate, typically disk shaped with a hole in its centre. Used in combination with a threaded fastener such as nuts and bolts, washers aid in the distribution of load. Although washers are usually produced from plastic or metal such as stainless steel, their use in a particular application would determine their use.  For instance if the application requires high strength with moderate resistance to corrosion then grade 304 stainless steel is the material preferred. On the other hand, if oxidation corrosion and lightweight are considered to be the prime requirements, Inconel or any super duplex stainless steel grades are the preferred choices of metals.

Washers are fundamentally one of the most important devices that could be used to prevent galvanic corrosion. Especially since washers act as an insulator to steel screws or bolts from aluminium surfaces. High quality bolted joints, which are commonly seen in applications such as construction and machine design, regularly require hardened steel washers. When used in this manner a washer helps to prevent the loss of pre-load that could occur due to brinelling after the application of torque. Spring washers, when used along with bolts, prevent the loosening or fastening that is a result of vibrations, due to their axial flexibility. Another kind of spring washers is the locking washer which eliminates the fastening or loosening by stopping the unscrewing rotation of the fastening device, which in this case is the bolt.