SAE AS4716 piston and rod glands · SAE AS6235 face glands
O-ring gland dimensions
Groove width, gland depth, squeeze, corner radius, clearance and finish for every inch O-ring cross-section, by seal type and backup-ring count. The same rows the configurator cuts a gland from, and the ones our cylinder rebuild parts are authored to.
An O-ring seals because the gland squeezes it: the groove is cut a little shallower than the ring's cross-section W, and the width leaves room for the ring to spread under pressure. The gland design standards give, for each cross-section rather than each ring, the groove width G, the gland depth, the squeeze that depth produces, the inside corner radius and the surface finish the groove walls need. Pick a dash number and the gland follows from its section.
The tables cover the 5 inch cross-sections from 0.070″ to 0.275″ (AS568 series 0XX, 1XX, 2XX, 3XX, 4XX). Piston and rod glands are the radial glands of SAE AS4716, tabled with no, one and two anti-extrusion backup rings; the face gland is the static axial seal of SAE AS6235. Every row carries a band, not a nominal: the groove must finish inside it.
Place an O-ring on a diameter, in a bore or on a face in the configurator and it emits the groove from the matching row, cut to the middle of each band with half the band as the tolerance. The cylinder rebuild parts in the catalog are authored to the same rows, as the parts table shows.
Piston glands (O-ring on an OD, sealing in a bore)
| Cross-section W (in) | AS568 series | Groove width G (in) | Gland depth (in) | Squeeze | Finish Ra (µin) | Corner radius R (in) | Clearance, diametral (in) |
|---|---|---|---|---|---|---|---|
| No backup ring | |||||||
| 0.070 | 0XX | 0.094 to 0.099 | 0.053 to 0.061 | 4 to 28% | 32 | 0.005 to 0.015 | 0.002 to 0.005 |
| 0.103 | 1XX | 0.141 to 0.151 | 0.082 to 0.094 | 5 to 21% | 32 | 0.005 to 0.015 | 0.002 to 0.007 |
| 0.139 | 2XX | 0.188 to 0.198 | 0.117 to 0.129 | 4 to 19% | 32 | 0.010 to 0.025 | 0.002 to 0.008 |
| 0.210 | 3XX | 0.281 to 0.291 | 0.181 to 0.194 | 4 to 16% | 32 | 0.020 to 0.035 | 0.003 to 0.008 |
| 0.275 | 4XX | 0.375 to 0.385 | 0.233 to 0.250 | 7 to 17% | 32 | 0.020 to 0.035 | 0.004 to 0.011 |
| One backup ring | |||||||
| 0.070 | 0XX | 0.150 to 0.160 | 0.053 to 0.061 | 4 to 28% | 32 | 0.005 to 0.015 | 0.002 to 0.005 |
| 0.103 | 1XX | 0.183 to 0.193 | 0.082 to 0.094 | 5 to 21% | 32 | 0.005 to 0.015 | 0.002 to 0.007 |
| 0.139 | 2XX | 0.235 to 0.245 | 0.117 to 0.129 | 4 to 19% | 32 | 0.010 to 0.025 | 0.002 to 0.008 |
| 0.210 | 3XX | 0.334 to 0.344 | 0.181 to 0.194 | 4 to 16% | 32 | 0.020 to 0.035 | 0.003 to 0.008 |
| 0.275 | 4XX | 0.475 to 0.485 | 0.233 to 0.250 | 7 to 17% | 32 | 0.020 to 0.035 | 0.004 to 0.011 |
| Two backup rings | |||||||
| 0.070 | 0XX | 0.207 to 0.217 | 0.053 to 0.061 | 4 to 28% | 32 | 0.005 to 0.015 | 0.002 to 0.005 |
| 0.103 | 1XX | 0.245 to 0.255 | 0.082 to 0.094 | 5 to 21% | 32 | 0.005 to 0.015 | 0.002 to 0.007 |
| 0.139 | 2XX | 0.304 to 0.314 | 0.117 to 0.129 | 4 to 19% | 32 | 0.010 to 0.025 | 0.002 to 0.008 |
| 0.210 | 3XX | 0.424 to 0.434 | 0.181 to 0.194 | 4 to 16% | 32 | 0.020 to 0.035 | 0.003 to 0.008 |
| 0.275 | 4XX | 0.579 to 0.589 | 0.233 to 0.250 | 7 to 17% | 32 | 0.020 to 0.035 | 0.004 to 0.011 |
SAE AS4716 as reproduced in the Machinery's Handbook O-ring tables. Groove width and gland depth are the band the finished groove must land in; backup rings widen the groove and leave the depth unchanged. Depth is radial.
Rod glands (O-ring in a bore, sealing on a rod)
| Cross-section W (in) | AS568 series | Groove width G (in) | Gland depth (in) | Squeeze | Finish Ra (µin) | Corner radius R (in) | Clearance, diametral (in) | Lead-in chamfer (in) |
|---|---|---|---|---|---|---|---|---|
| No backup ring | ||||||||
| 0.070 | 0XX | 0.094 to 0.099 | 0.053 to 0.061 | 4 to 28% | 32 | 0.005 to 0.015 | 0.002 to 0.005 | 0.018 |
| 0.103 | 1XX | 0.141 to 0.151 | 0.084 to 0.093 | 5 to 21% | 32 | 0.005 to 0.015 | 0.002 to 0.007 | 0.021 |
| 0.139 | 2XX | 0.188 to 0.198 | 0.117 to 0.129 | 4 to 19% | 32 | 0.010 to 0.025 | 0.002 to 0.008 | 0.023 |
| 0.210 | 3XX | 0.281 to 0.291 | 0.182 to 0.194 | 4 to 16% | 32 | 0.020 to 0.035 | 0.003 to 0.008 | 0.029 |
| 0.275 | 4XX | 0.375 to 0.385 | 0.233 to 0.250 | 7 to 17% | 32 | 0.020 to 0.035 | 0.004 to 0.011 | 0.043 |
| One backup ring | ||||||||
| 0.070 | 0XX | 0.150 to 0.160 | 0.053 to 0.061 | 4 to 28% | 32 | 0.005 to 0.015 | 0.002 to 0.005 | 0.018 |
| 0.103 | 1XX | 0.183 to 0.193 | 0.084 to 0.093 | 5 to 21% | 32 | 0.005 to 0.015 | 0.002 to 0.007 | 0.021 |
| 0.139 | 2XX | 0.235 to 0.245 | 0.117 to 0.129 | 4 to 19% | 32 | 0.010 to 0.025 | 0.002 to 0.008 | 0.023 |
| 0.210 | 3XX | 0.334 to 0.344 | 0.182 to 0.194 | 4 to 16% | 32 | 0.020 to 0.035 | 0.003 to 0.008 | 0.029 |
| 0.275 | 4XX | 0.475 to 0.485 | 0.233 to 0.250 | 7 to 17% | 32 | 0.020 to 0.035 | 0.004 to 0.011 | 0.043 |
| Two backup rings | ||||||||
| 0.070 | 0XX | 0.207 to 0.217 | 0.053 to 0.061 | 4 to 28% | 32 | 0.005 to 0.015 | 0.002 to 0.005 | 0.018 |
| 0.103 | 1XX | 0.245 to 0.255 | 0.084 to 0.093 | 5 to 21% | 32 | 0.005 to 0.015 | 0.002 to 0.007 | 0.021 |
| 0.139 | 2XX | 0.304 to 0.314 | 0.117 to 0.129 | 4 to 19% | 32 | 0.010 to 0.025 | 0.002 to 0.008 | 0.023 |
| 0.210 | 3XX | 0.424 to 0.434 | 0.182 to 0.194 | 4 to 16% | 32 | 0.020 to 0.035 | 0.003 to 0.008 | 0.029 |
| 0.275 | 4XX | 0.579 to 0.589 | 0.233 to 0.250 | 7 to 17% | 32 | 0.020 to 0.035 | 0.004 to 0.011 | 0.043 |
SAE AS4716 as reproduced in the Machinery's Handbook O-ring tables. Groove width and gland depth are the band the finished groove must land in; backup rings widen the groove and leave the depth unchanged. Depth is radial.
Face glands (static axial seal)
| Cross-section W (in) | AS568 series | Groove width G (in) | Gland depth (in) | Squeeze | Finish Ra (µin) | Corner radius R (in) |
|---|---|---|---|---|---|---|
| 0.070 | 0XX | 0.098 to 0.103 | 0.056 to 0.060 | 10 to 23% | 32 | 0.005 to 0.015 |
| 0.103 | 1XX | 0.141 to 0.151 | 0.086 to 0.090 | 10 to 19% | 32 | 0.005 to 0.015 |
| 0.139 | 2XX | 0.188 to 0.198 | 0.117 to 0.121 | 10 to 18% | 32 | 0.010 to 0.025 |
| 0.210 | 3XX | 0.281 to 0.291 | 0.178 to 0.184 | 10 to 17% | 32 | 0.020 to 0.035 |
| 0.275 | 4XX | 0.375 to 0.385 | 0.234 to 0.242 | 10 to 17% | 32 | 0.020 to 0.035 |
SAE AS6235 as reproduced in the Machinery's Handbook O-ring tables. Groove width and gland depth are the band the finished groove must land in. Depth is axial, into the face.
Cylinder parts and the gland each carries
| Part | Group | Gland | Cross-section W (series) | Cut width × depth (in) | Table band |
|---|---|---|---|---|---|
| Cylinder Piston, 1-1/2" Bore | Pistons | piston gland (groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Cylinder Piston, 2" Bore | Pistons | piston gland (groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Cylinder Piston, 2-1/2" Bore | Pistons | piston gland (groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Cylinder Piston, 3-1/4" Bore | Pistons | piston gland (groove) | 0.210 (3XX) | 0.286 × 0.194 | 0.281 to 0.291 × 0.181 to 0.194 |
| Rod Gland, 1" Rod | Rod Glands | rod gland (bore-groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Rod Gland, 1" Rod | Rod Glands | piston gland (groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Rod Gland, 1-3/8" Rod | Rod Glands | rod gland (bore-groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Rod Gland, 1-3/8" Rod | Rod Glands | piston gland (groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Rod Gland, 1-3/4" Rod | Rod Glands | rod gland (bore-groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Rod Gland, 1-3/4" Rod | Rod Glands | piston gland (groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| O-ring Plug, 1-1/4" OD | O-ring Plugs | piston gland (groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| O-ring Plug, 1-1/2" OD | O-ring Plugs | piston gland (groove) | 0.139 (2XX) | 0.193 × 0.129 | 0.188 to 0.198 × 0.117 to 0.129 |
| Port Flange, 2-1/2" OD | Port Flanges | face gland (face-groove) | 0.139 (2XX) | 0.193 × 0.119 | 0.188 to 0.198 × 0.117 to 0.121 |
| Port Flange, 3-1/2" OD | Port Flanges | face gland (face-groove) | 0.139 (2XX) | 0.193 × 0.119 | 0.188 to 0.198 × 0.117 to 0.121 |
| Port Flange, 4" OD | Port Flanges | face gland (face-groove) | 0.139 (2XX) | 0.193 × 0.119 | 0.188 to 0.198 × 0.117 to 0.121 |
Computed from the part data: each seal groove is matched to the no-backup row whose width and depth bands contain the cut dimensions.
Backup rings widen the groove, not the depth
For the 0.139″ (2XX) section the piston groove width is 0.188 to 0.198 with no backup ring, 0.235 to 0.245 with one and 0.304 to 0.314 with two, while the gland depth stays 0.117 to 0.129 in all three: the backup ring takes axial room beside the O-ring and changes nothing about the squeeze. Pick the backup count from the pressure and the extrusion gap; the table does the rest.
A face gland for the same 0.139″ section is 0.188 to 0.198 wide and 0.117 to 0.121 deep, a tighter depth band than the radial gland's 0.117 to 0.129, and it carries a higher minimum squeeze (10 to 18% against 4 to 19%) because a static face seal has no running clearance to lose. Groove walls on every gland in the table are finished to 32 µin Ra.
Which cylinder parts carry which gland
12 cylinder rebuild parts carry an O-ring gland from these tables. Pistons seal on an OD groove (piston gland); rod glands carry two bore grooves for the rod seal and wiper (rod gland) plus an OD static groove that seals the gland into the head (a piston gland by geometry); O-ring plugs seal on an OD groove; port flanges seal on a face groove (face gland). The parts are cut to the middle of the no-backup width band and to the maximum of the depth band, which is minimum squeeze and lowest breakaway friction, with the depth tolerance running downward only so the groove stays inside the published window.
Frequently Asked Questions
These references are for specifying a part; every value here is one the configurator applies when you build one. Numbers are representative of the standard; check them against your part and its mating components before ordering. See all guides on the guides page.