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  4. BS 4320 British Standard Black Metal Washers

BS 4320 British Standard Black Metal Washers

BS 4320 British Standard Black Metal Washers

BS 4320 British Standard Black Metal Washers(Normal Diameter Sizes (Form E))

Nom Bolt or Screw Size Inside Diameter Outside Diameter Thickness
Nom Max Min Nom Max Min Nom Max Min
BS 4320 - M 5 5.5 5.8 5.5 10 10 9.2 1 1.2 0.8
BS 4320 - M 6 6.6 7 6.6 12.5 12.5 11.7 1.6 1.9 1.3
BS 4320 - M 7 7.6 8 7.6 14 14 13.2 1.6 1.9 1.3
BS 4320 - M 8 9 9.4 9 17 17 16.2 1.6 1.9 1.3
BS 4320 - M 10 11 11.5 11 21 21 20.2 2 2.3 1.7
BS 4320 - M 12 14 14.5 14 24 24 23.2 2.5 2.8 2.2
BS 4320 - M 14 16 16.5 16 28 28 27.2 2.5 2.8 2.2
BS 4320 - M 16 18 18.5 18 30 30 29.2 3 3.6 2.4
BS 4320 - M 18 20 20.6 20 34 34 32.8 3 3.6 2.4
BS 4320 - M 20 22 22.6 22 37 37 35.8 3 3.6 2.4
BS 4320 - M 22 24 24.6 24 39 39 37.8 3 3.6 2.4
BS 4320 - M 24 26 26.6 26 44 44 42.8 4 4.6 3.4
BS 4320 - M 27 30 30.6 30 50 50 48.8 4 4.6 3.4
BS 4320 - M 30 33 33.8 33 56 56 54.5 4 4.6 3.4
BS 4320 - M 33 36 36.8 36 60 60 58.5 5 6 4
BS 4320 - M 36 39 39.8 39 66 66 64.5 5 6 4
BS 4320 - M 39 42 42.8 42 72 72 70.5 6 7 5
BS 4320 - M 42 45 45.8 45 78 78 76.5 7 8.2 5.8
BS 4320 - M 45 48 48.8 48 85 85 83 7 8.2 5.8
BS 4320 - M 48 52 53 52 92 92 90 8 9.2 6.8
BS 4320 - M 52 56 57 56 98 98 96 8 9.2 6.8
BS 4320 - M 56 62 63 62 105 105 103 9 10.2 7.8
BS 4320 - M 60 66 67 66 110 110 108 9 10.2 7.8
BS 4320 - M 64 70 71 70 115 115 113 9 10.2 7.8
BS 4320 - M 68 74 75 74 120 120 118 10 11.2 8.8

BS 4320 British Standard Black Metal Washers(Large Diameter Sizes (Form F))

Nom Bolt or Screw Size Inside Diameter Outside Diameter Thickness
Nom Max Min Nom Max Min Nom Max Min
BS 4320 - M 8 9 9.4 9 21 21 20.2 1.6 1.9 1.3
BS 4320 - M 10 11 11.5 11 24 24 23.2 2 2.3 1.7
BS 4320 - M 12 14 14.5 14 28 28 27.2 2.5 2.8 2.2
BS 4320 - M 14 16 16.5 16 30 30 29.2 2.5 2.8 2.2
BS 4320 - M 16 18 18.5 18 34 34 32.8 3 3.6 2.4
BS 4320 - M 18 20 20.6 20 37 37 35.8 3 3.6 2.4
BS 4320 - M 20 22 22.6 22 39 39 37.8 3 3.6 2.4
BS 4320 - M 22 24 24.6 24 44 44 42.8 3 3.6 2.4
BS 4320 - M 24 26 26.6 26 50 50 48.8 4 4.6 3.4
BS 4320 - M 27 30 30.6 30 56 56 54.5 4 4.6 3.4
BS 4320 - M 30 33 33.8 33 60 60 58.5 4 4.6 3.4
BS 4320 - M 33 36 36.8 36 66 66 64.5 5 6 4
BS 4320 - M 36 39 39.8 39 72 72 70.5 5 6 4
BS 4320 - M 39 42 42.8 42 77 77 75.5 6 7 5

BS 4320 British Standard Black Metal Washers(Extra Large Diameter Sizes (Form G))

Nom Bolt or Screw Size Inside Diameter Outside Diameter Thickness
Nom Max Min Nom Max Min Nom Max Min
BS 4320 - M 5 5.5 5.8 5.5 15 15 14.2 1.6 1.9 1.3
BS 4320 - M 6 6.6 7 6.6 18 18 17.2 2 2.3 1.7
BS 4320 - M 7 7.6 8 7.6 21 21 20.2 2 2.3 1.7
BS 4320 - M 8 9 9.4 9 24 24 23.2 2 2.3 1.7
BS 4320 - M 10 11 11.5 11 30 30 29.2 2.5 2.8 2.2
BS 4320 - M 12 14 14.5 14 36 36 34.8 3 3.6 2.4
BS 4320 - M 14 16 16.5 16 42 42 40.8 3 3.6 2.4
BS 4320 - M 16 18 18.5 18 48 48 46.8 4 4.6 3.4
BS 4320 - M 18 20 20.6 20 54 54 52.5 4 4.6 3.4
BS 4320 - M 20 22 22.6 22 60 60 58.5 5 6 4
BS 4320 - M 22 24 24.6 24 66 66 64.5 5 6 4
BS 4320 - M 24 26 26.6 26 72 72 70.5 6 7 5
BS 4320 - M 27 30 30.6 30 81 81 79 6 7 5
BS 4320 - M 30 33 33.8 33 90 90 88 8 9.2 6.8
BS 4320 - M 33 36 36.8 36 99 99 97 8 9.2 6.8
BS 4320 - M 36 39 39.8 39 108 108 106 10 11.2 8.8
BS 4320 - M39 42 42.8 42 117 117 115 10 11.2 8.8
  • All dimensions are in millimeters.
  • Nominal bolt or screw sizes shown in parentheses are nonpreferred.