Techsil are proud to be a preferred distributer of Trelleborg Sealing Solutions for O-Rings and Bonded Seals. Specifying the right o-ring seal can be difficult because there are many different conditions to be considered such as:

  1. Material selection: Application parameters; Medium to be sealed; Working temperature; Working pressure; Type of use (dynamic, static); Necessary physical and mechanical properties E.g. hardness; Applicable standards or approvals (e.g. defence standards and institutional approvals for drinking water application)
  2. Housing layout, groove layout and O-Ring size: Method of O-Ring installation/type of use - Axial (static) or Radial (dynamic or static); Groove design; Groove width; Groove/housing height; Rounded edges and lead-in chamfers for easier installation; Radial clearance (sealing gap); Surface finish of the groove diameter, groove flanks and the mating surface; Initial compression of the O-Ring; Elongation –outside diameter interference of the O-Ring; Groove fill; Tolerances
  3. O-Ring quality: Dimensional tolerances - Inside diameter, Cross section ISO 3601-1 is recommended; Surface quality - ISO 3601-3 is recommended; Applicable standards
  4. Correct O-Ring installation: Stretching - Level of stretching, Speed of stretching, Design of assembly tool; O-Ring twisting – Lubrication, Assembly tools; O-Ring damage - Use of assembly tools, Design of assembly tool

The online O-Ring Calculator from our partners Trelleborg, offers engineers and professionals a quick and easy way to calculate O-Ring dimensions and the appropriate housing layout in accordance with the international O-Ring standard ISO 3601. By simply entering installation specifications for an application, it recommends O-Ring sizes, housing layout and corresponding part numbers.

Other Calculation Functions

  • For a selection of material type and hardness the total compression forces for the O-Rings can be calculated
  • Selection of application type
  • Radial applications can be differentiated between static and dynamic
  • Axial application can be differentiated between the internal pressure or external pressure
  • Different limits for calculation results are applied
  • Warning limits accurately follow the different recommendations in accordance with ISO 3601-2

The Trelleborg O-Ring Calculator is optimized for desktop devices but there is also an App version for mobile users.


View the O-Ring Calculator here.

For any other O-Ring enquiries contact Techsil on technical@techsil.co.uk