About Cylinder Seals
![](https://www.mcmaster.com/prerenderstable/mvPRE/contents/gfx/small/j05-sealsc1-digitals.png?ver=1496220287)
Rod wipers scrape dirt, dust, and moisture from the rod, preventing contamination inside your cylinder.
Rod seals maintain the pressure inside cylinders and prevent fluid from leaking out.
Wear rings guide the rod and piston to prevent uneven wear and optimize seal performance.
Head seals are a more reliable alternative to the standard O-ring/backup ring combination—they resist twisting and remain stable even in applications with fluctuating pressure.
Buffering seals protect hydraulic cylinders from pressure spikes and shock in high-pressure hydraulic applications.
Cushioning seals minimize wear and noise in air-powered cylinders by preventing the piston from slamming against the cylinder body.
Piston seals make a seal between their outside edge and the cylinder bore to prevent internal leaks.
Heavy Duty Mechanical Pump Shaft Seals
![](/prerenderstable/mvPRE/contents/gfx/imagecache/156/1563n14-1629811314-p9@halfx_637653901177062213.png?ver=imagenotfound)
Multiple internal springs ensure these seals keep the sealing surfaces in contact in demanding applications, such as agricultural, chemical, and mining pumps. Seals come furnished as two pieces—the seal and the seat. The seal is comprised of the case, springs, diaphragm, and washer, and the seat is comprised of the seat and the gasket. Products cannot be sold outside North America due to restrictions.
Note: Maximum performance values cannot be achieved simultaneously; for example, speed is affected by pressure, temperature, and other operating conditions.
For technical drawings and 3-D models, click on a part number.
Seal | Seat | Material | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
For Shaft Dia. | Manufacturer/ Brand Equivalent | ID | OD | Wd. | ID | OD | Wd. | Washer | Seat | Max. Pressure, psi | Cannot Be Sold To | Each | |
316 Stainless Steel Case and Spring with Viton® Fluoroelastomer Rubber Diaphragm and Gasket | |||||||||||||
5/8" | John Crane Type 8T Pac-Seal Type 8T | 0.625" | 1.062" | 0.937" | 0.661" | 1.250" | 0.406" | Carbon | Ceramic | 300 | Outside North America | 0000000 | 0000000 |
3/4" | John Crane Type 8T Pac-Seal Type 8T | 0.750" | 1.187" | 0.937" | 0.781" | 1.375" | 0.406" | Carbon | Ceramic | 300 | Outside North America | 0000000 | 000000 |
1" | John Crane Type 8T Pac-Seal Type 8T | 1.000" | 1.437" | 1.000" | 1.064" | 1.625" | 0.437" | Carbon | Ceramic | 300 | Outside North America | 0000000 | 000000 |
1 1/4" | John Crane Type 8T Pac-Seal Type 8T | 1.250" | 1.687" | 1.000" | 1.281" | 1.875" | 0.437" | Carbon | Ceramic | 300 | Outside North America | 0000000 | 000000 |
1 1/2" | John Crane Type 8T Pac-Seal Type 8T | 1.500" | 1.937" | 1.125" | 1.546" | 2.125" | 0.437" | Carbon | Silicon Carbide | 300 | Outside North America | 0000000 | 00000000 |
Spring-Loaded Seals
![](/prerenderstable/mvPRE/contents/gfx/imagecache/131/13125k12-2@halfx_636924916114513764.png?ver=imagenotfound)
![](/prerenderstable/mvPRE/contents/gfx/imagecache/131/13125k12-1@halfx_636924915964032708.png?ver=imagenotfound)
![](/prerenderstable/mvPRE/contents/gfx/imagecache/131/13125k12-2b@halfx_636924916103230922.png?ver=imagenotfound)
![](/prerenderstable/mvPRE/contents/gfx/imagecache/j05/j05-groovedimsforspringloadedsealsinpistongroovel1-digital-master1548106505-p9@halfx_636598988887800000.png?ver=imagenotfound)
![](/prerenderstable/mvPRE/contents/gfx/imagecache/j05/j05-groovedimsforspringloadedsealsl1-digital-master1548106505-p9@halfx_636598988887880000.png?ver=imagenotfound)
In addition to providing excellent sealing performance at low pressure, these seals withstand a wider range of temperatures and chemicals than U-cup seals. They’re also known as spring-energized seals. They have a sealing lip on both the inside and outside edges, so they can be used for rod and piston sealing. Pistons require two seals—install one facing in each direction.
PTFE seals withstand a wider range of temperatures and chemicals than UHMW seals.
Graphite-filled seals have greater wear resistance and strength than seals without a filler.
Note: Maximum performance values cannot be achieved simultaneously; for example, speed is affected by pressure, temperature, and other operating conditions.
For technical drawings and 3-D models, click on a part number.
For Rod Sealing | For Piston Sealing | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
For Rod Dia. | For Groove Dia. | For Bore Dia. | For Groove Dia. | Max. Speed, ft./sec. | Max. Pressure, psi | Temperature Range, °F | Hardness | Color | Each | |
PTFE Plastic with 302 Stainless Steel Spring | ||||||||||
For 0.056" Groove Wd. | ||||||||||
1/8" | 0.188" | 3/16" | 0.125" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 000000 |
For 0.101" Groove Wd. | ||||||||||
1/8" | 0.250" | 1/4" | 0.125" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
3/16" | 0.313" | 5/16" | 0.188" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
1/4" | 0.375" | 3/8" | 0.250" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
3/8" | 0.500" | 1/2" | 0.375" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
For 0.149" Groove Wd. | ||||||||||
3/16" | 0.375" | 3/8" | 0.188" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
1/4" | 0.438" | 7/16" | 0.250" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
3/8" | 0.563" | 9/16" | 0.375" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
1/2" | 0.688" | 11/16" | 0.500" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
3/4" | 0.938" | 15/16" | 0.750" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
For 0.188" Groove Wd. | ||||||||||
1/2" | 0.750" | 3/4" | 0.500" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
3/4" | 1.000" | 1" | 0.750" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
1" | 1.250" | 1 1/4" | 1.000" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
1 1/4" | 1.500" | 1 1/2" | 1.250" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
1 1/2" | 1.750" | 1 3/4" | 1.500" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
2" | 2.250" | 2 1/4" | 2.000" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
For 0.268" Groove Wd. | ||||||||||
1 1/2" | 1.875" | 1 7/8" | 1.500" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 00000 |
2 1/2" | 2.875" | 2 7/8" | 2.500" | 1.6 | 250 | -320° to 450° | Not Rated | White | 00000000 | 000000 |
Graphite-Filled PTFE Plastic with 302 Stainless Steel Spring | ||||||||||
For 0.056" Groove Wd. | ||||||||||
1/8" | 0.188" | 3/16" | 0.125" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
For 0.101" Groove Wd. | ||||||||||
1/8" | 0.250" | 1/4" | 0.125" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
3/16" | 0.313" | 5/16" | 0.188" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
1/4" | 0.375" | 3/8" | 0.250" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
3/8" | 0.500" | 1/2" | 0.375" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
For 0.149" Groove Wd. | ||||||||||
3/16" | 0.375" | 3/8" | 0.188" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
1/4" | 0.438" | 7/16" | 0.250" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
3/8" | 0.563" | 9/16" | 0.375" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
1/2" | 0.688" | 11/16" | 0.500" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
3/4" | 0.938" | 15/16" | 0.750" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
For 0.188" Groove Wd. | ||||||||||
1/2" | 0.750" | 3/4" | 0.500" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
3/4" | 1.000" | 1" | 0.750" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
1" | 1.250" | 1 1/4" | 1.000" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
1 1/4" | 1.500" | 1 1/2" | 1.250" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
1 1/2" | 1.750" | 1 3/4" | 1.500" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
2" | 2.250" | 2 1/4" | 2.000" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 00000 |
For 0.268" Groove Wd. | ||||||||||
1 1/2" | 1.875" | 1 7/8" | 1.500" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 000000 |
2 1/2" | 2.875" | 2 7/8" | 2.500" | 1.6 | 250 | -320° to 450° | Not Rated | Black | 00000000 | 000000 |