Dynamic Groove Spec Table
This specification follows JIS (Japanese Industrial Standards). JIS is highly compatible with Korean KS standards and is essential when sourcing or maintaining Japanese-manufactured parts and equipment.
O-ring groove dimensions for dynamic (reciprocating) applications such as pistons and rods, ensuring proper squeeze ratio for seal performance.
Practical Notes
- Always deburr groove edges. Microscopic burrs can cut O-rings, causing critical hydraulic leaks.
Selection Guide
O-ring groove dimensions for reciprocating pistons and rods. 8–16% compression minimizes friction; groove bottom surface roughness Ra 0.2–0.4μm is essential. Corner radius machining prevents O-ring damage.
JISDynamic Groove
4 sizes| Wire/Use | Groove D | Groove W | Squeeze | Note | - |
|---|---|---|---|---|---|
| CS1.9Dynamic | 1.55 | 2.4 | 18% | Piston/Rod | - |
| CS2.4Dynamic | 1.95 | 3 | 19% | Piston/Rod | - |
| CS3.5Dynamic | 2.8 | 4.6 | 20% | Piston/Rod | - |
| CS5.7Dynamic | 4.6 | 7.5 | 19% | Piston/Rod | - |
Key Features
- O-ring slides without rolling within groove during piston/rod reciprocation
- Groove width is 1.2–1.3× cord diameter; 8–16% compression minimizes friction and wear
- Surface roughness Ra 0.2–0.4 μm required; groove bottom radius chamfer prevents O-ring damage
Key Applications
Hydraulic cylinder piston seals, pneumatic cylinder rod packing, solenoid valve spools, hydraulic press rams
FAQ
Surface roughness requirements for dynamic O-ring grooves?
Groove bottom Ra 0.2–0.4μm, groove sides Ra 0.4–0.8μm are mandatory. High roughness accelerates O-ring wear and causes leakage.