O ring Groove Calculator

To calculate O-Ring Groove dimensions, input O-Ring Inner Diameter (ID) and Cross-Section (CS) in millimeters. If inner diameter is 15 mm and cross-section is 2.5 mm, enter these values in their respective fields, select seal type (static or dynamic).

Click Calculate to view Groove Width, Groove Depth, Groove Diameter, Gland Fill, and Stretch Percentage.

How to Calculate an O-Ring Groove?

To calculate an O-ring groove, first identify the O-ring cross-sectional diameter. Calculate groove depth by multiplying O-ring diameter by one minus compression percentage.

Determine groove width by multiplying O-ring diameter by 1.3 for static seals or 1.8 for dynamic seals. For external grooves, calculate groove diameter by subtracting twice cross-section times stretch percentage from O-ring ID.

For internal grooves, add this value instead. Set corner radii to 0.1 times O-ring diameter. Verify that groove fill is appropriate and dimensions meet material requirements.

Formula for O-Ring Groove

Groove Width (W)

W = CS × Factor
where:
Factor = 1.30 for static seals
Factor = 1.25 for dynamic seals

Groove Depth (D)

D = CS × Factor
where:
Factor = 0.75 for static seals
Factor = 0.70 for dynamic seals

Mean Groove Diameter (MGD)

MGD = Hardware ID + CS
where:
Hardware ID = Inner diameter of the housing
CS = O-ring cross-section

Gland Fill Percentage

Gland Fill = (O-ring Volume / Groove Volume) × 100
where:
O-ring Volume = π × (CS/2)² × (π × ID + π × CS)
Groove Volume = π × W × D × MGD

Stretch Percentage

Stretch = (MGD - ID) / ID × 100
where:
MGD = Mean Groove Diameter
ID = O-ring Inside Diameter

Example 1: Static Seal

• ID = 15 mm, CS = 2.5 mm
• Groove Width = 2.5 × 1.30 = 3.25 mm
• Groove Depth = 2.5 × 0.75 = 1.875 mm
• Mean Groove Diameter = 17.5 mm
• Gland Fill = 83.2%
• Stretch = 2.8%

Example 2: Dynamic Seal

• ID = 25 mm, CS = 3.5 mm
• Groove Width = 3.5 × 1.25 = 4.375 mm
• Groove Depth = 3.5 × 0.70 = 2.45 mm
• Mean Groove Diameter = 28.5 mm
• Gland Fill = 74.5%
• Stretch = 2.1%

Example 3: Static Seal

• ID = 20 mm, CS = 3.0 mm
• Groove Width = 3.0 × 1.30 = 3.90 mm
• Groove Depth = 3.0 × 0.75 = 2.25 mm
• Mean Groove Diameter = 23.0 mm
• Gland Fill = 84.1%
• Stretch = 3.2%

Example 4: Dynamic Seal

• ID = 30 mm, CS = 4.0 mm
• Groove Width = 4.0 × 1.25 = 5.0 mm
• Groove Depth = 4.0 × 0.70 = 2.8 mm
• Mean Groove Diameter = 34.0 mm
• Gland Fill = 73.8%
• Stretch = 2.7%

Example 5: Static Seal

• ID = 40 mm, CS = 5.0 mm
• Groove Width = 5.0 × 1.30 = 6.5 mm
• Groove Depth = 5.0 × 0.75 = 3.75 mm
• Mean Groove Diameter = 45.0 mm
• Gland Fill = 84.7%
• Stretch = 3.9%

What is an O-Ring Groove?

An O-ring groove is a precisely machined channel or recess designed to house an O-ring seal. The groove dimensions are critical for maintaining proper compression (squeeze) on the O-ring while preventing over-compression or extrusion. For static applications, the groove provides a stable housing that ensures consistent sealing pressure, while dynamic applications require specific groove geometries to accommodate movement while maintaining seal integrity. Proper groove design considers factors such as pressure, temperature, material properties, and service conditions to achieve optimal sealing performance.