Serrated Safety Washers

Light Duty and Medium Duty Safety Washers

39 different sizes in stock from 1.60mm to 30mm Screw Size

This range of safety washers is based on the disc spring concept. The washer has the unique feature of radial serrations on both the concave and convex surfaces. When final flattening of the serrated safety washer occurs with the tightening of the screw, the serrations bite into the mating faces, thus preventing loosening of the screw caused by vibration.

Diagram of a serrated safety washer showing the dimension choices

The disc spring profile will also assist in retaining the required screw tension.

The safety washer offers a reduced outside diameter compared with a conventional disc spring a Belleville spring washer. This corresponds to most screw head sizes and is very compatible with the hexagonal socket type screw.


Light Duty - Measurements are in millimeters & weight in kilograms


Code Number


Screw Size (mm)


Outer Dia. (De) (mm)


Inner Dia.(Di) (mm)


Thickness (t) (mm)


Total Height (Lo) (mm)


Weight per 1000 (Kg)


Screw Size (inch)

S3217035 1.60 3.20 1.70 0.35 0.60 0.016  
S422035 2.00 4.00 2.20 0.35 0.60 0.017  
S4827045 2.50 4.80 2.70 0.45 0.90 0.040  
S5532045 3.00 5.50 3.20 0.45 0.90 0.044 1/8
S637045 3.50 6.00 3.70 0.45 0.90 0.049  
S74305 4.00 7.00 4.30 0.50 1.00 0.077 5/32
S95306 5.00 9.00 5.30 0.60 1.10 0.167 3/16
S106407 6.00 10.00 6.40 0.70 1.20 0.206  
S956707 6.35 9.50 6.70 0.70 1.20 0.168 1/4
S127407 7.00 12.00 7.40 0.70 1.30 0.312  
S138408 8.00 13.00 8.40 0.80 1.40 0.402 1/16
S161051 10.00 16.00 10.50 1.00 1.60 0.773 1/8
S1591161 11.10 15.90 11.60 1.00 1.60 0.660 1/16
S181311 12.00 18.00 13.00 1.10 1.70 0.970  
S1913711 12.70 19.00 13.70 1.10 1.80 1.082 1/2
S221512 14.00 22.00 15.00 1.20 2.00 1.805  
S241713 16.00 24.00 17.00 1.30 2.10 2.115 5/8
S271915 18.00 27.00 19.00 1.50 2.30 2.945  
S302015 19.00 30.00 20.00 1.50 2.40 4.080 3/4
S302115 20.00 30.00 21.00 1.50 2.40 3.710  
S332315 22.00 33.00 23.00 1.50 2.50 4.548 7/8
S3625618 24.00 36.00 25.60 1.80 2.70 6.260  
S38272 25.40 38.00 27.00 2.00 2.80 7.220 1
S392862 27.00 39.00 28.60 2.00 2.90 6.880  
S453162 30.00 45.00 31.60 2.00 3.20 11.320 1 1/8
S543825 36.00 54.00 38.00 2.50 4.00 21.900  


Medium Duty - Measurements are in millimeters & weight in kilograms


Code Number


Screw Size (mm)


Outer Dia. (De) (mm)


Inner Dia.(Di) (mm)


Thickness (t) (mm)


Total Height (Lo) (mm)


Weight per 1000 (Kg)


Screw Size (inch)

VS9531 5.00 9.00 5.30 1.00 1.30 0.29 3/16
VS10641 6.00 10.00 6.40 1.00 1.40 0.31  
VS138412 8.00 13.00 8.40 1.20 1.70 0.59 5/16
VS1610515 10.00 16.00 10.50 1.50 2.00 1.12 3/8
VS181315 12.00 18.00 13.00 1.50 2.10 1.12  
VS221515 14.00 22.00 15.00 1.50 2.20 1.90  
VS24172 16.00 24.00 17.00 2.00 2.60 2.70 5/8
VS27192 18.00 27.00 19.00 2.00 2.70 3.53  
VS30212 20.00 30.00 21.00 2.00 2.80 4.35  
VS33232 22.00 33.00 23.00 2.00 2.90 5.84 7/8
VS3625625 24.00 36.00 25.60 2.50 3.30 8.00  
VS3928625 27.00 39.00 28.60 2.50 3.40 7.66  
VS4531625 30.00 45.00 31.60 2.50 3.60 13.70 1 1/8

Please use our disc spring enquiry form for competitive quotes and stock enquiries.



Institute of Spring TechnologyMember of UK Spring Manufacturers AssociationBelleville QualityBritish Valve and Actuator Association

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