Backup rings for AS568 O-rings (Parker 8-xxx Parbak, 8-004 to 8-475): ID, OD, width and thickness per dash size — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/backup-rings-as568-parker-8-xxx/ (sheet CC BY 4.0) Basis: Parker O-Ring Division's Parbak 8-xxx table (ID per size, series header values for width and thickness), cross-checked against McMaster-Carr's printed backup-ring table (190 sizes); 344 uncut ring envelopes as files Catalog version: 2026-10-20 Sizes: see table below - Parker's 8-xxx table lists 346 sizes in five series (8-004 to 8-050, 8-102 to 8-178, 8-201 to 8-284, 8-309 to 8-395, 8-425 to 8-475), each 'designed to correspond with the Parker 2-xxx, 3-xxx and AS568B series O-ring with which they are used'. The dash number is the O-ring's: 8-214 goes beside a -214 O-ring. Note that the series 8-0xx starts at 004 (no 8-001 to 8-003) and 8-1xx at 102. - Columns: ID is Parker's printed inside diameter in inches. W (radial width) is .053 / .086 / .118 / .183 / .236 in for series 0xx / 1xx / 2xx / 3xx / 4xx and T (thickness, Parker's 'Ref.' value) is .049 / .053 / .050 / .076 / .117 in; both are the values Parker prints above each series and McMaster-Carr prints the same width group and 'Thk.' for every series it sells. OD = ID + 2 x W: McMaster's printed OD equals that for every size it lists except 8-223. Millimetres are the inch values x 25.4 rounded to 0.01 mm. Parker's header also carries other numbers and tolerances whose letters the page text does not define; they are not used here. - Cross-check: McMaster-Carr prints ID and OD for 190 of the sizes (8-004 to 8-031, 8-042, 8-103 to 8-155, 8-158, 8-202 to 8-265, 8-320 to 8-351, 8-358 and 11 of the 4xx sizes); the IDs equal Parker's for every one except 8-344 (Parker 3.989, McMaster 3.898, both shown, no file) and the OD for 8-223 differs (McMaster prints OD 1.833 for 8-223; ID + 2 x 0.118 = 1.883 and every other McMaster row fits that rule, so 1.833 reads as a misprint on one side; both shown). - 8-176: Parker prints 9.238; the sizes either side are 9.018 (8-175) and 9.518 (8-177), step 0.25 would be 9.268, and no second source lists it, so the value is left out. Nothing was substituted. - Not covered: MS28774 (PTFE spiral / scarf-cut back-up rings) and AS5781 are searched under those names but no dimension table with numbers was readable, so none of their sizes or gaps are listed; do not assume they equal Parker's rubber Parbak numbers. Material, durometer and split style are not given in the Parker page text read. - Files: uncut rectangular ring envelopes at ID, OD = ID + 2W and thickness T. A molded Parbak has a contoured (concave) face and a PTFE ring is split; neither profile is published as numbers in the sources read, so the file is the space the ring occupies, not its exact face. Both disputed sizes (8-176, 8-344) have no file. The AS568 O-ring of the same dash is on as568-o-rings; groove widths that allow for one or two backup rings are on oring-gland-static-radial-as568 and oring-gland-dynamic-reciprocating-as568. McMaster-Carr sells backup rings with per-part STEP; its page is linked, not copied. dash ID (in) OD (in) = ID + 2W radial width W (in) thickness T (in) ID (mm) OD (mm) T (mm) cross-check 8-004 0.096 0.202 0.053 0.049 2.44 5.13 1.24 McMaster ID and OD agree 8-005 0.127 0.233 0.053 0.049 3.23 5.92 1.24 McMaster ID and OD agree 8-006 0.140 0.246 0.053 0.049 3.56 6.25 1.24 McMaster ID and OD agree 8-007 0.171 0.277 0.053 0.049 4.34 7.04 1.24 McMaster ID and OD agree 8-008 0.202 0.308 0.053 0.049 5.13 7.82 1.24 McMaster ID and OD agree 8-009 0.234 0.340 0.053 0.049 5.94 8.64 1.24 McMaster ID and OD agree 8-010 0.265 0.371 0.053 0.049 6.73 9.42 1.24 McMaster ID and OD agree 8-011 0.327 0.433 0.053 0.049 8.31 11.00 1.24 McMaster ID and OD agree 8-012 0.390 0.496 0.053 0.049 9.91 12.60 1.24 McMaster ID and OD agree 8-013 0.455 0.561 0.053 0.049 11.56 14.25 1.24 McMaster ID and OD agree 8-014 0.518 0.624 0.053 0.049 13.16 15.85 1.24 McMaster ID and OD agree 8-015 0.580 0.686 0.053 0.049 14.73 17.42 1.24 McMaster ID and OD agree 8-016 0.643 0.749 0.053 0.049 16.33 19.02 1.24 McMaster ID and OD agree 8-017 0.705 0.811 0.053 0.049 17.91 20.60 1.24 McMaster ID and OD agree 8-018 0.768 0.874 0.053 0.049 19.51 22.20 1.24 McMaster ID and OD agree 8-019 0.830 0.936 0.053 0.049 21.08 23.77 1.24 McMaster ID and OD agree 8-020 0.893 0.999 0.053 0.049 22.68 25.37 1.24 McMaster ID and OD agree 8-021 0.955 1.061 0.053 0.049 24.26 26.95 1.24 McMaster ID and OD agree 8-022 1.018 1.124 0.053 0.049 25.86 28.55 1.24 McMaster ID and OD agree 8-023 1.080 1.186 0.053 0.049 27.43 30.12 1.24 McMaster ID and OD agree 8-024 1.143 1.249 0.053 0.049 29.03 31.72 1.24 McMaster ID and OD agree 8-025 1.205 1.311 0.053 0.049 30.61 33.30 1.24 McMaster ID and OD agree 8-026 1.268 1.374 0.053 0.049 32.21 34.90 1.24 McMaster ID and OD agree 8-027 1.330 1.436 0.053 0.049 33.78 36.47 1.24 McMaster ID and OD agree 8-028 1.393 1.499 0.053 0.049 35.38 38.07 1.24 McMaster ID and OD agree 8-029 1.518 1.624 0.053 0.049 38.56 41.25 1.24 McMaster ID and OD agree 8-030 1.643 1.749 0.053 0.049 41.73 44.42 1.24 McMaster ID and OD agree 8-031 1.768 1.874 0.053 0.049 44.91 47.60 1.24 McMaster ID and OD agree 8-032 1.893 1.999 0.053 0.049 48.08 50.77 1.24 — 8-033 2.018 2.124 0.053 0.049 51.26 53.95 1.24 — 8-034 2.143 2.249 0.053 0.049 54.43 57.12 1.24 — 8-035 2.268 2.374 0.053 0.049 57.61 60.30 1.24 — 8-036 2.393 2.499 0.053 0.049 60.78 63.47 1.24 — 8-037 2.518 2.624 0.053 0.049 63.96 66.65 1.24 — 8-038 2.643 2.749 0.053 0.049 67.13 69.82 1.24 — 8-039 2.768 2.874 0.053 0.049 70.31 73.00 1.24 — 8-040 2.893 2.999 0.053 0.049 73.48 76.17 1.24 — 8-041 3.018 3.124 0.053 0.049 76.66 79.35 1.24 — 8-042 3.268 3.374 0.053 0.049 83.01 85.70 1.24 McMaster ID and OD agree 8-043 3.518 3.624 0.053 0.049 89.36 92.05 1.24 — 8-044 3.768 3.874 0.053 0.049 95.71 98.40 1.24 — 8-045 4.018 4.124 0.053 0.049 102.06 104.75 1.24 — 8-046 4.268 4.374 0.053 0.049 108.41 111.10 1.24 — 8-047 4.518 4.624 0.053 0.049 114.76 117.45 1.24 — 8-048 4.768 4.874 0.053 0.049 121.11 123.80 1.24 — 8-049 5.018 5.124 0.053 0.049 127.46 130.15 1.24 — 8-050 5.268 5.374 0.053 0.049 133.81 136.50 1.24 — 8-102 0.077 0.249 0.086 0.053 1.96 6.32 1.35 — 8-103 0.109 0.281 0.086 0.053 2.77 7.14 1.35 McMaster ID and OD agree 8-104 0.140 0.312 0.086 0.053 3.56 7.92 1.35 McMaster ID and OD agree 8-105 0.171 0.343 0.086 0.053 4.34 8.71 1.35 McMaster ID and OD agree 8-106 0.202 0.374 0.086 0.053 5.13 9.50 1.35 McMaster ID and OD agree 8-107 0.234 0.406 0.086 0.053 5.94 10.31 1.35 McMaster ID and OD agree 8-108 0.265 0.437 0.086 0.053 6.73 11.10 1.35 McMaster ID and OD agree 8-109 0.327 0.499 0.086 0.053 8.31 12.67 1.35 McMaster ID and OD agree 8-110 0.390 0.562 0.086 0.053 9.91 14.27 1.35 McMaster ID and OD agree 8-111 0.452 0.624 0.086 0.053 11.48 15.85 1.35 McMaster ID and OD agree 8-112 0.515 0.687 0.086 0.053 13.08 17.45 1.35 McMaster ID and OD agree 8-113 0.577 0.749 0.086 0.053 14.66 19.02 1.35 McMaster ID and OD agree 8-114 0.640 0.812 0.086 0.053 16.26 20.62 1.35 McMaster ID and OD agree 8-115 0.702 0.874 0.086 0.053 17.83 22.20 1.35 McMaster ID and OD agree 8-116 0.765 0.937 0.086 0.053 19.43 23.80 1.35 McMaster ID and OD agree 8-117 0.831 1.003 0.086 0.053 21.11 25.48 1.35 McMaster ID and OD agree 8-118 0.893 1.065 0.086 0.053 22.68 27.05 1.35 McMaster ID and OD agree 8-119 0.956 1.128 0.086 0.053 24.28 28.65 1.35 McMaster ID and OD agree 8-120 1.018 1.190 0.086 0.053 25.86 30.23 1.35 McMaster ID and OD agree 8-121 1.081 1.253 0.086 0.053 27.46 31.83 1.35 McMaster ID and OD agree 8-122 1.143 1.315 0.086 0.053 29.03 33.40 1.35 McMaster ID and OD agree 8-123 1.206 1.378 0.086 0.053 30.63 35.00 1.35 McMaster ID and OD agree 8-124 1.268 1.440 0.086 0.053 32.21 36.58 1.35 McMaster ID and OD agree 8-125 1.331 1.503 0.086 0.053 33.81 38.18 1.35 McMaster ID and OD agree 8-126 1.393 1.565 0.086 0.053 35.38 39.75 1.35 McMaster ID and OD agree 8-127 1.456 1.628 0.086 0.053 36.98 41.35 1.35 McMaster ID and OD agree 8-128 1.518 1.690 0.086 0.053 38.56 42.93 1.35 McMaster ID and OD agree 8-129 1.581 1.753 0.086 0.053 40.16 44.53 1.35 McMaster ID and OD agree 8-130 1.643 1.815 0.086 0.053 41.73 46.10 1.35 McMaster ID and OD agree 8-131 1.706 1.878 0.086 0.053 43.33 47.70 1.35 McMaster ID and OD agree 8-132 1.768 1.940 0.086 0.053 44.91 49.28 1.35 McMaster ID and OD agree 8-133 1.831 2.003 0.086 0.053 46.51 50.88 1.35 McMaster ID and OD agree 8-134 1.893 2.065 0.086 0.053 48.08 52.45 1.35 McMaster ID and OD agree 8-135 1.956 2.128 0.086 0.053 49.68 54.05 1.35 McMaster ID and OD agree 8-136 2.018 2.190 0.086 0.053 51.26 55.63 1.35 McMaster ID and OD agree 8-137 2.081 2.253 0.086 0.053 52.86 57.23 1.35 McMaster ID and OD agree 8-138 2.143 2.315 0.086 0.053 54.43 58.80 1.35 McMaster ID and OD agree 8-139 2.206 2.378 0.086 0.053 56.03 60.40 1.35 McMaster ID and OD agree 8-140 2.268 2.440 0.086 0.053 57.61 61.98 1.35 McMaster ID and OD agree 8-141 2.331 2.503 0.086 0.053 59.21 63.58 1.35 McMaster ID and OD agree 8-142 2.393 2.565 0.086 0.053 60.78 65.15 1.35 McMaster ID and OD agree 8-143 2.456 2.628 0.086 0.053 62.38 66.75 1.35 McMaster ID and OD agree 8-144 2.518 2.690 0.086 0.053 63.96 68.33 1.35 McMaster ID and OD agree 8-145 2.581 2.753 0.086 0.053 65.56 69.93 1.35 McMaster ID and OD agree 8-146 2.643 2.815 0.086 0.053 67.13 71.50 1.35 McMaster ID and OD agree 8-147 2.706 2.878 0.086 0.053 68.73 73.10 1.35 McMaster ID and OD agree 8-148 2.768 2.940 0.086 0.053 70.31 74.68 1.35 McMaster ID and OD agree 8-149 2.831 3.003 0.086 0.053 71.91 76.28 1.35 McMaster ID and OD agree 8-150 2.893 3.065 0.086 0.053 73.48 77.85 1.35 McMaster ID and OD agree 8-151 3.018 3.190 0.086 0.053 76.66 81.03 1.35 McMaster ID and OD agree 8-152 3.268 3.440 0.086 0.053 83.01 87.38 1.35 McMaster ID and OD agree 8-153 3.518 3.690 0.086 0.053 89.36 93.73 1.35 McMaster ID and OD agree 8-154 3.768 3.940 0.086 0.053 95.71 100.08 1.35 McMaster ID and OD agree 8-155 4.018 4.190 0.086 0.053 102.06 106.43 1.35 McMaster ID and OD agree 8-156 4.268 4.440 0.086 0.053 108.41 112.78 1.35 — 8-157 4.518 4.690 0.086 0.053 114.76 119.13 1.35 — 8-158 4.768 4.940 0.086 0.053 121.11 125.48 1.35 McMaster ID and OD agree 8-159 5.018 5.190 0.086 0.053 127.46 131.83 1.35 — 8-160 5.268 5.440 0.086 0.053 133.81 138.18 1.35 — 8-161 5.518 5.690 0.086 0.053 140.16 144.53 1.35 — 8-162 5.768 5.940 0.086 0.053 146.51 150.88 1.35 — 8-163 6.018 6.190 0.086 0.053 152.86 157.23 1.35 — 8-164 6.268 6.440 0.086 0.053 159.21 163.58 1.35 — 8-165 6.518 6.690 0.086 0.053 165.56 169.93 1.35 — 8-166 6.768 6.940 0.086 0.053 171.91 176.28 1.35 — 8-167 7.018 7.190 0.086 0.053 178.26 182.63 1.35 — 8-168 7.268 7.440 0.086 0.053 184.61 188.98 1.35 — 8-169 7.518 7.690 0.086 0.053 190.96 195.33 1.35 — 8-170 7.768 7.940 0.086 0.053 197.31 201.68 1.35 — 8-171 8.018 8.190 0.086 0.053 203.66 208.03 1.35 — 8-172 8.268 8.440 0.086 0.053 210.01 214.38 1.35 — 8-173 8.518 8.690 0.086 0.053 216.36 220.73 1.35 — 8-174 8.768 8.940 0.086 0.053 222.71 227.08 1.35 — 8-175 9.018 9.190 0.086 0.053 229.06 233.43 1.35 — 8-176 — (see note) — 0.086 0.053 — — 1.35 not corroborated 8-177 9.518 9.690 0.086 0.053 241.76 246.13 1.35 — 8-178 9.768 9.940 0.086 0.053 248.11 252.48 1.35 — 8-201 0.202 0.438 0.118 0.050 5.13 11.13 1.27 — 8-202 0.265 0.501 0.118 0.050 6.73 12.73 1.27 McMaster ID and OD agree 8-203 0.327 0.563 0.118 0.050 8.31 14.30 1.27 McMaster ID and OD agree 8-204 0.390 0.626 0.118 0.050 9.91 15.90 1.27 McMaster ID and OD agree 8-205 0.455 0.691 0.118 0.050 11.56 17.55 1.27 McMaster ID and OD agree 8-206 0.518 0.754 0.118 0.050 13.16 19.15 1.27 McMaster ID and OD agree 8-207 0.580 0.816 0.118 0.050 14.73 20.73 1.27 McMaster ID and OD agree 8-208 0.643 0.879 0.118 0.050 16.33 22.33 1.27 McMaster ID and OD agree 8-209 0.705 0.941 0.118 0.050 17.91 23.90 1.27 McMaster ID and OD agree 8-210 0.766 1.002 0.118 0.050 19.46 25.45 1.27 McMaster ID and OD agree 8-211 0.828 1.064 0.118 0.050 21.03 27.03 1.27 McMaster ID and OD agree 8-212 0.891 1.127 0.118 0.050 22.63 28.63 1.27 McMaster ID and OD agree 8-213 0.953 1.189 0.118 0.050 24.21 30.20 1.27 McMaster ID and OD agree 8-214 1.016 1.252 0.118 0.050 25.81 31.80 1.27 McMaster ID and OD agree 8-215 1.078 1.314 0.118 0.050 27.38 33.38 1.27 McMaster ID and OD agree 8-216 1.141 1.377 0.118 0.050 28.98 34.98 1.27 McMaster ID and OD agree 8-217 1.203 1.439 0.118 0.050 30.56 36.55 1.27 McMaster ID and OD agree 8-218 1.266 1.502 0.118 0.050 32.16 38.15 1.27 McMaster ID and OD agree 8-219 1.334 1.570 0.118 0.050 33.88 39.88 1.27 McMaster ID and OD agree 8-220 1.397 1.633 0.118 0.050 35.48 41.48 1.27 McMaster ID and OD agree 8-221 1.459 1.695 0.118 0.050 37.06 43.05 1.27 McMaster ID and OD agree 8-222 1.522 1.758 0.118 0.050 38.66 44.65 1.27 McMaster ID and OD agree 8-223 1.647 1.883 0.118 0.050 41.83 47.83 1.27 McMaster ID agrees; OD printed 1.833 (see note) 8-224 1.772 2.008 0.118 0.050 45.01 51.00 1.27 McMaster ID and OD agree 8-225 1.897 2.133 0.118 0.050 48.18 54.18 1.27 McMaster ID and OD agree 8-226 2.022 2.258 0.118 0.050 51.36 57.35 1.27 McMaster ID and OD agree 8-227 2.147 2.383 0.118 0.050 54.53 60.53 1.27 McMaster ID and OD agree 8-228 2.272 2.508 0.118 0.050 57.71 63.70 1.27 McMaster ID and OD agree 8-229 2.397 2.633 0.118 0.050 60.88 66.88 1.27 McMaster ID and OD agree 8-230 2.522 2.758 0.118 0.050 64.06 70.05 1.27 McMaster ID and OD agree 8-231 2.631 2.867 0.118 0.050 66.83 72.82 1.27 McMaster ID and OD agree 8-232 2.756 2.992 0.118 0.050 70.00 76.00 1.27 McMaster ID and OD agree 8-233 2.881 3.117 0.118 0.050 73.18 79.17 1.27 McMaster ID and OD agree 8-234 3.006 3.242 0.118 0.050 76.35 82.35 1.27 McMaster ID and OD agree 8-235 3.131 3.367 0.118 0.050 79.53 85.52 1.27 McMaster ID and OD agree 8-236 3.256 3.492 0.118 0.050 82.70 88.70 1.27 McMaster ID and OD agree 8-237 3.381 3.617 0.118 0.050 85.88 91.87 1.27 McMaster ID and OD agree 8-238 3.506 3.742 0.118 0.050 89.05 95.05 1.27 McMaster ID and OD agree 8-239 3.631 3.867 0.118 0.050 92.23 98.22 1.27 McMaster ID and OD agree 8-240 3.756 3.992 0.118 0.050 95.40 101.40 1.27 McMaster ID and OD agree 8-241 3.881 4.117 0.118 0.050 98.58 104.57 1.27 McMaster ID and OD agree 8-242 4.006 4.242 0.118 0.050 101.75 107.75 1.27 McMaster ID and OD agree 8-243 4.131 4.367 0.118 0.050 104.93 110.92 1.27 McMaster ID and OD agree 8-244 4.256 4.492 0.118 0.050 108.10 114.10 1.27 McMaster ID and OD agree 8-245 4.381 4.617 0.118 0.050 111.28 117.27 1.27 McMaster ID and OD agree 8-246 4.506 4.742 0.118 0.050 114.45 120.45 1.27 McMaster ID and OD agree 8-247 4.631 4.867 0.118 0.050 117.63 123.62 1.27 McMaster ID and OD agree 8-248 4.768 5.004 0.118 0.050 121.11 127.10 1.27 McMaster ID and OD agree 8-249 4.893 5.129 0.118 0.050 124.28 130.28 1.27 McMaster ID and OD agree 8-250 5.018 5.254 0.118 0.050 127.46 133.45 1.27 McMaster ID and OD agree 8-251 5.143 5.379 0.118 0.050 130.63 136.63 1.27 McMaster ID and OD agree 8-252 5.268 5.504 0.118 0.050 133.81 139.80 1.27 McMaster ID and OD agree 8-253 5.393 5.629 0.118 0.050 136.98 142.98 1.27 McMaster ID and OD agree 8-254 5.518 5.754 0.118 0.050 140.16 146.15 1.27 McMaster ID and OD agree 8-255 5.643 5.879 0.118 0.050 143.33 149.33 1.27 McMaster ID and OD agree 8-256 5.768 6.004 0.118 0.050 146.51 152.50 1.27 McMaster ID and OD agree 8-257 5.893 6.129 0.118 0.050 149.68 155.68 1.27 McMaster ID and OD agree 8-258 6.018 6.254 0.118 0.050 152.86 158.85 1.27 McMaster ID and OD agree 8-259 6.268 6.504 0.118 0.050 159.21 165.20 1.27 McMaster ID and OD agree 8-260 6.518 6.754 0.118 0.050 165.56 171.55 1.27 McMaster ID and OD agree 8-261 6.768 7.004 0.118 0.050 171.91 177.90 1.27 McMaster ID and OD agree 8-262 7.018 7.254 0.118 0.050 178.26 184.25 1.27 McMaster ID and OD agree 8-263 7.268 7.504 0.118 0.050 184.61 190.60 1.27 McMaster ID and OD agree 8-264 7.518 7.754 0.118 0.050 190.96 196.95 1.27 McMaster ID and OD agree 8-265 7.768 8.004 0.118 0.050 197.31 203.30 1.27 McMaster ID and OD agree 8-266 8.018 8.254 0.118 0.050 203.66 209.65 1.27 — 8-267 8.268 8.504 0.118 0.050 210.01 216.00 1.27 — 8-268 8.518 8.754 0.118 0.050 216.36 222.35 1.27 — 8-269 8.768 9.004 0.118 0.050 222.71 228.70 1.27 — 8-270 9.018 9.254 0.118 0.050 229.06 235.05 1.27 — 8-271 9.268 9.504 0.118 0.050 235.41 241.40 1.27 — 8-272 9.518 9.754 0.118 0.050 241.76 247.75 1.27 — 8-273 9.768 10.004 0.118 0.050 248.11 254.10 1.27 — 8-274 10.018 10.254 0.118 0.050 254.46 260.45 1.27 — 8-275 10.518 10.754 0.118 0.050 267.16 273.15 1.27 — 8-276 11.018 11.254 0.118 0.050 279.86 285.85 1.27 — 8-277 11.518 11.754 0.118 0.050 292.56 298.55 1.27 — 8-278 12.018 12.254 0.118 0.050 305.26 311.25 1.27 — 8-279 13.018 13.254 0.118 0.050 330.66 336.65 1.27 — 8-280 14.018 14.254 0.118 0.050 356.06 362.05 1.27 — 8-281 15.018 15.254 0.118 0.050 381.46 387.45 1.27 — 8-282 15.989 16.225 0.118 0.050 406.12 412.12 1.27 — 8-283 16.989 17.225 0.118 0.050 431.52 437.51 1.27 — 8-284 17.989 18.225 0.118 0.050 456.92 462.92 1.27 — 8-309 0.450 0.816 0.183 0.076 11.43 20.73 1.93 — 8-310 0.513 0.879 0.183 0.076 13.03 22.33 1.93 — 8-311 0.575 0.941 0.183 0.076 14.60 23.90 1.93 — 8-312 0.638 1.004 0.183 0.076 16.21 25.50 1.93 — 8-313 0.700 1.066 0.183 0.076 17.78 27.08 1.93 — 8-314 0.763 1.129 0.183 0.076 19.38 28.68 1.93 — 8-315 0.825 1.191 0.183 0.076 20.95 30.25 1.93 — 8-316 0.888 1.254 0.183 0.076 22.56 31.85 1.93 — 8-317 0.950 1.316 0.183 0.076 24.13 33.43 1.93 — 8-318 1.013 1.379 0.183 0.076 25.73 35.03 1.93 — 8-319 1.075 1.441 0.183 0.076 27.30 36.60 1.93 — 8-320 1.138 1.504 0.183 0.076 28.91 38.20 1.93 McMaster ID and OD agree 8-321 1.200 1.566 0.183 0.076 30.48 39.78 1.93 McMaster ID and OD agree 8-322 1.263 1.629 0.183 0.076 32.08 41.38 1.93 McMaster ID and OD agree 8-323 1.316 1.682 0.183 0.076 33.43 42.72 1.93 McMaster ID and OD agree 8-324 1.388 1.754 0.183 0.076 35.26 44.55 1.93 McMaster ID and OD agree 8-325 1.513 1.879 0.183 0.076 38.43 47.73 1.93 McMaster ID and OD agree 8-326 1.638 2.004 0.183 0.076 41.61 50.90 1.93 McMaster ID and OD agree 8-327 1.763 2.129 0.183 0.076 44.78 54.08 1.93 McMaster ID and OD agree 8-328 1.888 2.254 0.183 0.076 47.96 57.25 1.93 McMaster ID and OD agree 8-329 2.013 2.379 0.183 0.076 51.13 60.43 1.93 McMaster ID and OD agree 8-330 2.138 2.504 0.183 0.076 54.31 63.60 1.93 McMaster ID and OD agree 8-331 2.268 2.634 0.183 0.076 57.61 66.90 1.93 McMaster ID and OD agree 8-332 2.393 2.759 0.183 0.076 60.78 70.08 1.93 McMaster ID and OD agree 8-333 2.518 2.884 0.183 0.076 63.96 73.25 1.93 McMaster ID and OD agree 8-334 2.643 3.009 0.183 0.076 67.13 76.43 1.93 McMaster ID and OD agree 8-335 2.768 3.134 0.183 0.076 70.31 79.60 1.93 McMaster ID and OD agree 8-336 2.893 3.259 0.183 0.076 73.48 82.78 1.93 McMaster ID and OD agree 8-337 3.018 3.384 0.183 0.076 76.66 85.95 1.93 McMaster ID and OD agree 8-338 3.143 3.509 0.183 0.076 79.83 89.13 1.93 McMaster ID and OD agree 8-339 3.273 3.639 0.183 0.076 83.13 92.43 1.93 McMaster ID and OD agree 8-340 3.398 3.764 0.183 0.076 86.31 95.61 1.93 McMaster ID and OD agree 8-341 3.523 3.889 0.183 0.076 89.48 98.78 1.93 McMaster ID and OD agree 8-342 3.648 4.014 0.183 0.076 92.66 101.96 1.93 McMaster ID and OD agree 8-343 3.773 4.139 0.183 0.076 95.83 105.13 1.93 McMaster ID and OD agree 8-344 3.989 (Parker) / 3.898 (McMaster) 4.355 / 4.264 0.183 0.076 101.32 / 99.01 110.62 / 108.31 1.93 sources disagree: no file 8-345 4.028 4.394 0.183 0.076 102.31 111.61 1.93 McMaster ID and OD agree 8-346 4.153 4.519 0.183 0.076 105.49 114.78 1.93 McMaster ID and OD agree 8-347 4.278 4.644 0.183 0.076 108.66 117.96 1.93 McMaster ID and OD agree 8-348 4.403 4.769 0.183 0.076 111.84 121.13 1.93 McMaster ID and OD agree 8-349 4.528 4.894 0.183 0.076 115.01 124.31 1.93 McMaster ID and OD agree 8-350 4.653 5.019 0.183 0.076 118.19 127.48 1.93 McMaster ID and OD agree 8-351 4.778 5.144 0.183 0.076 121.36 130.66 1.93 McMaster ID and OD agree 8-352 4.903 5.269 0.183 0.076 124.54 133.83 1.93 — 8-353 5.028 5.394 0.183 0.076 127.71 137.01 1.93 — 8-354 5.153 5.519 0.183 0.076 130.89 140.18 1.93 — 8-355 5.278 5.644 0.183 0.076 134.06 143.36 1.93 — 8-356 5.403 5.769 0.183 0.076 137.24 146.53 1.93 — 8-357 5.528 5.894 0.183 0.076 140.41 149.71 1.93 — 8-358 5.653 6.019 0.183 0.076 143.59 152.88 1.93 McMaster ID and OD agree 8-359 5.778 6.144 0.183 0.076 146.76 156.06 1.93 — 8-360 5.903 6.269 0.183 0.076 149.94 159.23 1.93 — 8-361 6.028 6.394 0.183 0.076 153.11 162.41 1.93 — 8-362 6.278 6.644 0.183 0.076 159.46 168.76 1.93 — 8-363 6.528 6.894 0.183 0.076 165.81 175.11 1.93 — 8-364 6.778 7.144 0.183 0.076 172.16 181.46 1.93 — 8-365 7.028 7.394 0.183 0.076 178.51 187.81 1.93 — 8-366 7.278 7.644 0.183 0.076 184.86 194.16 1.93 — 8-367 7.528 7.894 0.183 0.076 191.21 200.51 1.93 — 8-368 7.778 8.144 0.183 0.076 197.56 206.86 1.93 — 8-369 8.028 8.394 0.183 0.076 203.91 213.21 1.93 — 8-370 8.278 8.644 0.183 0.076 210.26 219.56 1.93 — 8-371 8.528 8.894 0.183 0.076 216.61 225.91 1.93 — 8-372 8.778 9.144 0.183 0.076 222.96 232.26 1.93 — 8-373 9.028 9.394 0.183 0.076 229.31 238.61 1.93 — 8-374 9.278 9.644 0.183 0.076 235.66 244.96 1.93 — 8-375 9.528 9.894 0.183 0.076 242.01 251.31 1.93 — 8-376 9.778 10.144 0.183 0.076 248.36 257.66 1.93 — 8-377 10.028 10.394 0.183 0.076 254.71 264.01 1.93 — 8-378 10.528 10.894 0.183 0.076 267.41 276.71 1.93 — 8-379 11.028 11.394 0.183 0.076 280.11 289.41 1.93 — 8-380 11.528 11.894 0.183 0.076 292.81 302.11 1.93 — 8-381 12.028 12.394 0.183 0.076 305.51 314.81 1.93 — 8-382 13.028 13.394 0.183 0.076 330.91 340.21 1.93 — 8-383 14.028 14.394 0.183 0.076 356.31 365.61 1.93 — 8-384 15.028 15.394 0.183 0.076 381.71 391.01 1.93 — 8-385 16.008 16.374 0.183 0.076 406.60 415.90 1.93 — 8-386 17.008 17.374 0.183 0.076 432.00 441.30 1.93 — 8-387 18.008 18.374 0.183 0.076 457.40 466.70 1.93 — 8-388 19.006 19.372 0.183 0.076 482.75 492.05 1.93 — 8-389 20.006 20.372 0.183 0.076 508.15 517.45 1.93 — 8-390 21.006 21.372 0.183 0.076 533.55 542.85 1.93 — 8-391 22.006 22.372 0.183 0.076 558.95 568.25 1.93 — 8-392 22.993 23.359 0.183 0.076 584.02 593.32 1.93 — 8-393 23.993 24.359 0.183 0.076 609.42 618.72 1.93 — 8-394 24.993 25.359 0.183 0.076 634.82 644.12 1.93 — 8-395 25.993 26.359 0.183 0.076 660.22 669.52 1.93 — 8-425 4.551 5.023 0.236 0.117 115.60 127.58 2.97 — 8-426 4.676 5.148 0.236 0.117 118.77 130.76 2.97 McMaster ID and OD agree 8-427 4.801 5.273 0.236 0.117 121.95 133.93 2.97 McMaster ID and OD agree 8-428 4.926 5.398 0.236 0.117 125.12 137.11 2.97 — 8-429 5.051 5.523 0.236 0.117 128.30 140.28 2.97 McMaster ID and OD agree 8-430 5.176 5.648 0.236 0.117 131.47 143.46 2.97 — 8-431 5.301 5.773 0.236 0.117 134.65 146.63 2.97 — 8-432 5.426 5.898 0.236 0.117 137.82 149.81 2.97 — 8-433 5.551 6.023 0.236 0.117 141.00 152.98 2.97 McMaster ID and OD agree 8-434 5.676 6.148 0.236 0.117 144.17 156.16 2.97 — 8-435 5.801 6.273 0.236 0.117 147.35 159.33 2.97 — 8-436 5.926 6.398 0.236 0.117 150.52 162.51 2.97 — 8-437 6.051 6.523 0.236 0.117 153.70 165.68 2.97 McMaster ID and OD agree 8-438 6.274 6.746 0.236 0.117 159.36 171.35 2.97 — 8-439 6.524 6.996 0.236 0.117 165.71 177.70 2.97 McMaster ID and OD agree 8-440 6.774 7.246 0.236 0.117 172.06 184.05 2.97 — 8-441 7.024 7.496 0.236 0.117 178.41 190.40 2.97 — 8-442 7.274 7.746 0.236 0.117 184.76 196.75 2.97 — 8-443 7.524 7.996 0.236 0.117 191.11 203.10 2.97 McMaster ID and OD agree 8-444 7.774 8.246 0.236 0.117 197.46 209.45 2.97 — 8-445 8.024 8.496 0.236 0.117 203.81 215.80 2.97 — 8-446 8.524 8.996 0.236 0.117 216.51 228.50 2.97 McMaster ID and OD agree 8-447 9.024 9.496 0.236 0.117 229.21 241.20 2.97 — 8-448 9.524 9.996 0.236 0.117 241.91 253.90 2.97 — 8-449 10.024 10.496 0.236 0.117 254.61 266.60 2.97 — 8-450 10.524 10.996 0.236 0.117 267.31 279.30 2.97 — 8-451 11.024 11.496 0.236 0.117 280.01 292.00 2.97 McMaster ID and OD agree 8-452 11.524 11.996 0.236 0.117 292.71 304.70 2.97 McMaster ID and OD agree 8-453 12.024 12.496 0.236 0.117 305.41 317.40 2.97 — 8-454 12.524 12.996 0.236 0.117 318.11 330.10 2.97 — 8-455 13.024 13.496 0.236 0.117 330.81 342.80 2.97 — 8-456 13.524 13.996 0.236 0.117 343.51 355.50 2.97 — 8-457 14.024 14.496 0.236 0.117 356.21 368.20 2.97 — 8-458 14.524 14.996 0.236 0.117 368.91 380.90 2.97 — 8-459 15.024 15.496 0.236 0.117 381.61 393.60 2.97 — 8-460 15.524 15.996 0.236 0.117 394.31 406.30 2.97 — 8-461 16.004 16.476 0.236 0.117 406.50 418.49 2.97 — 8-462 16.504 16.976 0.236 0.117 419.20 431.19 2.97 — 8-463 17.004 17.476 0.236 0.117 431.90 443.89 2.97 — 8-464 17.504 17.976 0.236 0.117 444.60 456.59 2.97 — 8-465 18.004 18.476 0.236 0.117 457.30 469.29 2.97 — 8-466 18.504 18.976 0.236 0.117 470.00 481.99 2.97 — 8-467 19.004 19.476 0.236 0.117 482.70 494.69 2.97 — 8-468 19.504 19.976 0.236 0.117 495.40 507.39 2.97 — 8-469 20.004 20.476 0.236 0.117 508.10 520.09 2.97 — 8-470 21.004 21.476 0.236 0.117 533.50 545.49 2.97 — 8-471 22.004 22.476 0.236 0.117 558.90 570.89 2.97 — 8-472 23.004 23.476 0.236 0.117 584.30 596.29 2.97 — 8-473 24.004 24.476 0.236 0.117 609.70 621.69 2.97 — 8-474 25.004 25.476 0.236 0.117 635.10 647.09 2.97 — 8-475 26.004 26.476 0.236 0.117 660.50 672.49 2.97 — Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - Parker Hannifin O-Ring Division: Parbak backup rings 8-xxx: inside diameter per size, 8-004 to 8-475, five series headers (sizes 'correspond with the Parker 2-xxx, 3-xxx and AS568B series O-ring with which they are used') — web — Publisher's page; dimensions are facts — https://parker.com/content/dam/Parker-com/Literature/O-Ring-Division-Literature/Static-Files/8-xxx.pdf - McMaster-Carr: Oil-resistant Buna-N backup rings (dash number, width, thickness, ID, OD as printed) (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/buna-n-backup-rings Free files (CC BY 4.0, Xem Studio; STEP + STL, 344 parts): https://xemstudio.com/files/hardware/backup-rings-as568-parker-8-xxx/index.json API: https://xemstudio.com/api/geometry?object=backup-rings-as568-parker-8-xxx