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ASME B18.22.1 Type B Plain Washers

ASME B18.22.1 Type B Plain Washers

ASME B18.22.1 Type B Plain Washers Dimensions (mm)

Nominal Size Series Inside Diameter, A Outside Diameter, B Thickness, C
Basic Max. Min. Basic Max. Min. Basic Max. Min.
5/16 0.312 Narrow 8.737 18.414 5.512 15.875 25.552 12.65 1.6 45.796 36.118
5/16 0.312 Regular 8.737 18.414 5.512 22.225 31.902 17.704 1.6 45.796 36.118
5/16 0.312 Wide 8.737 18.414 5.512 28.575 38.252 24.054 1.6 45.796 36.118
3/8 0.375 Narrow 10.312 19.989 7.087 18.643 28.32 14.122 1.6 45.796 36.118
3/8 0.375 Regular 10.312 19.989 7.087 25.4 35.077 20.879 1.6 45.796 36.118
3/8 0.375 Wide 10.312 19.989 7.087 31.75 51.104 27.229 2.54 72.263 58.064
7/16 0.438 Narrow 11.912 21.589 8.687 22.225 31.902 17.704 1.6 45.796 36.118
7/16 0.438 Regular 11.912 21.589 8.687 28.575 38.252 24.054 1.6 45.796 36.118
7/16 0.438 Wide 11.912 21.589 8.687 37.312 56.666 32.791 2.54 72.263 58.064
1/2 0.5 Narrow 13.487 23.164 10.262 25.4 35.077 20.879 1.6 45.796 36.118
1/2 0.5 Regular 13.487 23.164 10.262 31.75 51.104 27.229 2.54 72.263 58.064
1/2 0.5 Wide 13.487 23.164 10.262 44.45 63.804 39.929 2.54 72.263 58.064
9/16 0.562 Narrow 15.087 24.764 11.862 28.575 38.252 24.054 1.6 45.796 36.118
9/16 0.562 Regular 15.087 24.764 11.862 37.312 56.666 32.791 2.54 72.263 58.064
9/16 0.562 Wide 15.087 24.764 11.862 50.8 70.154 46.279 2.54 72.263 58.064
5/8 0.625 Narrow 16.662 36.016 12.141 31.75 51.104 27.229 2.54 72.263 58.064
5/8 0.625 Regular 16.662 36.016 12.141 44.45 63.804 39.929 2.54 72.263 58.064
5/8 0.625 Wide 16.662 36.016 12.141 57.15 76.504 52.629 4.064 112.369 94.183
3/4 0.75 Narrow 20.624 39.978 16.103 34.925 54.279 30.404 2.54 72.263 58.064
3/4 0.75 Regular 20.624 39.978 16.103 50.8 70.154 46.279 2.54 72.263 58.064
3/4 0.75 Wide 20.624 39.978 16.103 63.5 82.854 58.979 4.064 112.369 94.183
7/8 0.875 Narrow 23.825 43.179 19.304 37.312 56.666 32.791 2.54 72.263 58.064
7/8 0.875 Regular 23.825 43.179 19.304 57.15 76.504 52.629 4.064 112.369 94.183
7/8 0.875 Wide 23.825 43.179 19.304 69.85 89.204 65.329 4.064 112.369 94.183
1 1 Narrow 26.974 46.328 22.453 44.45 63.804 39.929 2.54 72.263 58.064
1 1 Regular 26.974 46.328 22.453 63.5 82.854 58.979 4.064 112.369 94.183
1 1 Wide 26.974 46.328 22.453 76.2 95.554 71.679 4.064 112.369 94.183
11/8 1.125 Narrow 30.175 49.529 25.654 50.8 70.154 46.279 2.54 72.263 58.064
11/8 1.125 Regular 30.175 49.529 25.654 69.85 89.204 65.329 4.064 112.369 94.183
11/8 1.125 Wide 30.175 49.529 25.654 82.55 101.904 78.029 4.064 112.369 94.183
11/4 1.25 Narrow 33.324 52.678 28.803 57.15 76.504 52.629 4.064 112.369 94.183
11/4 1.25 Regular 33.324 52.678 28.803 76.2 95.554 71.679 4.064 112.369 94.183
11/4 1.25 Wide 33.324 62.356 26.873 88.9 117.932 82.449 6.35 171.602 150.977
13/8 1.375 Narrow 36.525 55.879 32.004 63.5 82.854 58.979 4.064 112.369 94.183
13/8 1.375 Regular 36.525 55.879 32.004 82.55 101.904 78.029 4.064 112.369 94.183
13/8 1.375 Wide 36.525 65.557 30.074 95.25 124.282 88.799 6.35 171.602 150.977
11/2 1.5 Narrow 39.674 59.028 35.153 69.85 89.204 65.329 4.064 112.369 94.183
11/2 1.5 Regular 39.674 68.706 33.223 88.9 117.932 82.449 6.35 171.602 150.977
11/2 1.5 Wide 39.674 68.706 33.223 101.6 130.632 95.149 6.35 171.602 150.977
15/8 1.625 Narrow 44.45 63.804 39.929 76.2 95.554 71.679 4.064 112.369 94.183
15/8 1.625 Regular 44.45 73.482 37.999 95.25 124.282 88.799 6.35 171.602 150.977
15/8 1.625 Wide 44.45 73.482 37.999 107.95 136.982 101.499 6.35 171.602 150.977
13/4 1.75 Narrow 47.625 66.979 43.104 82.55 101.904 78.029 4.064 112.369 94.183
13/4 1.75 Regular 47.625 76.657 41.174 101.6 130.632 95.149 6.35 171.602 150.977
13/4 1.75 Wide 47.625 76.657 41.174 114.3 143.332 107.849 6.35 171.602 150.977
17/8 1.875 Narrow 50.8 79.832 44.349 88.9 117.932 82.449 6.35 171.602 150.977
17/8 1.875 Regular 50.8 79.832 44.349 107.95 136.982 101.499 6.35 171.602 150.977
17/8 1.875 Wide 50.8 79.832 44.349 120.65 149.682 114.199 6.35 171.602 150.977
2 2 Narrow 53.975 83.007 47.524 95.25 124.282 88.799 6.35 171.602 150.977
2 2 Regular 53.975 83.007 47.524 114.3 143.332 107.849 6.35 171.602 150.977
2 2 Wide 53.975 83.007 47.524 127 156.032 120.549 6.35 171.602 150.977
21/4 2.25 Narrow 60.325 89.357 53.874 101.6 130.632 95.149 6.35 171.602 150.977
21/4 2.25 Regular 60.325 89.357 53.874 127 156.032 120.549 6.35 171.602 150.977
21/4 2.25 Wide 60.325 102.26 53.874 139.7 181.635 133.249 9.525 253.542 230.327
21/2 2.5 Narrow 66.675 95.707 60.224 114.3 143.332 107.849 6.35 171.602 150.977
21/2 2.5 Regular 66.675 108.61 60.224 139.7 181.635 133.249 9.525 253.542 230.327
21/2 2.5 Wide 66.675 108.61 60.224 152.4 194.335 145.949 9.525 253.542 230.327
23/4 2.75 Narrow 73.025 102.057 66.574 127 156.032 120.549 6.35 171.602 150.977
23/4 2.75 Regular 73.025 114.96 66.574 152.4 194.335 145.949 9.525 253.542 230.327
23/4 2.75 Wide 73.025 114.96 66.574 165.1 207.035 158.649 9.525 253.542 230.327
3 3 Narrow 79.375 121.31 72.924 139.7 181.635 133.249 9.525 253.542 230.327
3 3 Regular 79.375 121.31 72.924 165.1 207.035 158.649 9.525 253.542 230.327
3 3 Wide 79.375 121.31 72.924 177.8 219.735 171.349 9.525 253.542 230.327
  • a Nominal washer sizes are intended for use with comparable nominal screw or bolt sizes.
  • b N indicates Narrow; R, Regular; and W, Wide Series.
  • c The 18.644 mm and 37.313 mm outside diameter avoids washers which could be used in coin operated devices.
  • All dimensions are in millimeters.
  • Inside and outside diameters shall be concentric within at least the inside diameter tolerance.
  • Washers shall be flat within 0.127 mm for basic outside diameters up through 22.225 mm and within 0.254 mm for larger outside diameters.
  • For 2 1/4-, 2 1/2- , 2 3/4-, and 3-inch sizes see ASME B18.22.1-1965 (R1998).

ASME B18.22.1 Type B Plain Washers Dimensions (Inch)

Nominal Size Series Inside Diameter, A Outside Diameter, B Thickness, C
Basic Max. Min. Basic Max. Min. Basic Max. Min.
5/16 0.312 Narrow 0.34 0.725 0.217 0.63 1.006 0.498 0.06 1.803 1.422
5/16 0.312 Regular 0.34 0.725 0.217 0.88 1.256 0.697 0.06 1.803 1.422
5/16 0.312 Wide 0.34 0.725 0.217 1.13 1.506 0.947 0.06 1.803 1.422
3/8 0.375 Narrow 0.41 0.787 0.279 0.73 1.115 0.556 0.06 1.803 1.422
3/8 0.375 Regular 0.41 0.787 0.279 1.00 1.381 0.822 0.06 1.803 1.422
3/8 0.375 Wide 0.41 0.787 0.279 1.25 2.012 1.072 0.10 2.845 2.286
7/16 0.438 Narrow 0.47 0.850 0.342 0.88 1.256 0.697 0.06 1.803 1.422
7/16 0.438 Regular 0.47 0.850 0.342 1.13 1.506 0.947 0.06 1.803 1.422
7/16 0.438 Wide 0.47 0.850 0.342 1.47 2.231 1.291 0.10 2.845 2.286
1/2 0.5 Narrow 0.53 0.912 0.404 1.00 1.381 0.822 0.06 1.803 1.422
1/2 0.5 Regular 0.53 0.912 0.404 1.25 2.012 1.072 0.10 2.845 2.286
1/2 0.5 Wide 0.53 0.912 0.404 1.75 2.512 1.572 0.10 2.845 2.286
9/16 0.562 Narrow 0.59 0.975 0.467 1.13 1.506 0.947 0.06 1.803 1.422
9/16 0.562 Regular 0.59 0.975 0.467 1.47 2.231 1.291 0.10 2.845 2.286
9/16 0.562 Wide 0.59 0.975 0.467 2.00 2.762 1.822 0.10 2.845 2.286
5/8 0.625 Narrow 0.66 1.418 0.478 1.25 2.012 1.072 0.10 2.845 2.286
5/8 0.625 Regular 0.66 1.418 0.478 1.75 2.512 1.572 0.10 2.845 2.286
5/8 0.625 Wide 0.66 1.418 0.478 2.25 3.012 2.072 0.16 4.424 3.708
3/4 0.75 Narrow 0.81 1.574 0.634 1.38 2.137 1.197 0.10 2.845 2.286
3/4 0.75 Regular 0.81 1.574 0.634 2.00 2.762 1.822 0.10 2.845 2.286
3/4 0.75 Wide 0.81 1.574 0.634 2.50 3.262 2.322 0.16 4.424 3.708
7/8 0.875 Narrow 0.94 1.700 0.760 1.47 2.231 1.291 0.10 2.845 2.286
7/8 0.875 Regular 0.94 1.700 0.760 2.25 3.012 2.072 0.16 4.424 3.708
7/8 0.875 Wide 0.94 1.700 0.760 2.75 3.512 2.572 0.16 4.424 3.708
1 1 Narrow 1.06 1.824 0.884 1.75 2.512 1.572 0.10 2.845 2.286
1 1 Regular 1.06 1.824 0.884 2.50 3.262 2.322 0.16 4.424 3.708
1 1 Wide 1.06 1.824 0.884 3.00 3.762 2.822 0.16 4.424 3.708
11/8 1.125 Narrow 1.19 1.950 1.010 2.00 2.762 1.822 0.10 2.845 2.286
11/8 1.125 Regular 1.19 1.950 1.010 2.75 3.512 2.572 0.16 4.424 3.708
11/8 1.125 Wide 1.19 1.950 1.010 3.25 4.012 3.072 0.16 4.424 3.708
11/4 1.25 Narrow 1.31 2.074 1.134 2.25 3.012 2.072 0.16 4.424 3.708
11/4 1.25 Regular 1.31 2.074 1.134 3.00 3.762 2.822 0.16 4.424 3.708
11/4 1.25 Wide 1.31 2.455 1.058 3.50 4.643 3.246 0.25 6.756 5.944
13/8 1.375 Narrow 1.44 2.200 1.260 2.50 3.262 2.322 0.16 4.424 3.708
13/8 1.375 Regular 1.44 2.200 1.260 3.25 4.012 3.072 0.16 4.424 3.708
13/8 1.375 Wide 1.44 2.581 1.184 3.75 4.893 3.496 0.25 6.756 5.944
11/2 1.5 Narrow 1.56 2.324 1.384 2.75 3.512 2.572 0.16 4.424 3.708
11/2 1.5 Regular 1.56 2.705 1.308 3.50 4.643 3.246 0.25 6.756 5.944
11/2 1.5 Wide 1.56 2.705 1.308 4.00 5.143 3.746 0.25 6.756 5.944
15/8 1.625 Narrow 1.75 2.512 1.572 3.00 3.762 2.822 0.16 4.424 3.708
15/8 1.625 Regular 1.75 2.893 1.496 3.75 4.893 3.496 0.25 6.756 5.944
15/8 1.625 Wide 1.75 2.893 1.496 4.25 5.393 3.996 0.25 6.756 5.944
13/4 1.75 Narrow 1.88 2.637 1.697 3.25 4.012 3.072 0.16 4.424 3.708
13/4 1.75 Regular 1.88 3.018 1.621 4.00 5.143 3.746 0.25 6.756 5.944
13/4 1.75 Wide 1.88 3.018 1.621 4.50 5.643 4.246 0.25 6.756 5.944
17/8 1.875 Narrow 2.00 3.143 1.746 3.50 4.643 3.246 0.25 6.756 5.944
17/8 1.875 Regular 2.00 3.143 1.746 4.25 5.393 3.996 0.25 6.756 5.944
17/8 1.875 Wide 2.00 3.143 1.746 4.75 5.893 4.496 0.25 6.756 5.944
2 2 Narrow 2.13 3.268 1.871 3.75 4.893 3.496 0.25 6.756 5.944
2 2 Regular 2.13 3.268 1.871 4.50 5.643 4.246 0.25 6.756 5.944
2 2 Wide 2.13 3.268 1.871 5.00 6.143 4.746 0.25 6.756 5.944
21/4 2.25 Narrow 2.38 3.518 2.121 4.00 5.143 3.746 0.25 6.756 5.944
21/4 2.25 Regular 2.38 3.518 2.121 5.00 6.143 4.746 0.25 6.756 5.944
21/4 2.25 Wide 2.38 4.026 2.121 5.50 7.151 5.246 0.38 9.982 9.068
21/2 2.5 Narrow 2.63 3.768 2.371 4.50 5.643 4.246 0.25 6.756 5.944
21/2 2.5 Regular 2.63 4.276 2.371 5.50 7.151 5.246 0.38 9.982 9.068
21/2 2.5 Wide 2.63 4.276 2.371 6.00 7.651 5.746 0.38 9.982 9.068
23/4 2.75 Narrow 2.88 4.018 2.621 5.00 6.143 4.746 0.25 6.756 5.944
23/4 2.75 Regular 2.88 4.526 2.621 6.00 7.651 5.746 0.38 9.982 9.068
23/4 2.75 Wide 2.88 4.526 2.621 6.50 8.151 6.246 0.38 9.982 9.068
3 3 Narrow 3.13 4.776 2.871 5.50 7.151 5.246 0.38 9.982 9.068
3 3 Regular 3.13 4.776 2.871 6.50 8.151 6.246 0.38 9.982 9.068
3 3 Wide 3.13 4.776 2.871 7.00 8.651 6.746 0.38 9.982 9.068
  • a Nominal washer sizes are intended for use with comparable nominal screw or bolt sizes.
  • b N indicates Narrow; R, Regular; and W, Wide Series.
  • c The 0.734-inch and 1.469-inch outside diameter avoids washers which could be used in coin operated devices.
  • All dimensions are in inches.
  • Inside and outside diameters shall be concentric within at least the inside diameter tolerance.
  • Washers shall be flat within 0.005-inch for basic outside diameters up through 0.875-inch and within 0.010 inch for larger outside diameters.
  • For 21 ⁄ 4-, 21 ⁄ 2- , 23 ⁄ 4-, and 3-inch sizes see ASME B18.22.1-1965 (R1998).