Clamping Force Calculator

Determine the required clamping force to secure an optical component, with bolt torque estimation.

Retaining optics securely against vibration and gravitational loading requires the clamping normal force to generate sufficient friction to resist all applied forces with a design safety margin. The required normal force depends on the optic mass, orientation relative to gravity (vertical surface, horizontal top-mount, or inverted), peak acceleration load (in g), friction coefficient, and the number of clamps sharing the load. This tool's Optic Clamping mode calculates the minimum normal force per clamp and flags combinations that will slip under the specified loading. The Bolt Torque mode converts a required normal force into the wrench torque needed for a given metric bolt size (M2 through M6) using a standard metric thread torque model. Friction coefficient presets are provided for common contact pairs — glass on metal, steel on steel, PTFE on metal, and others.

Component & Mounting
Required Clamping Force
Component weight
0.4511N
Applied force (at design accel.)
0.4511N
Total normal force required
SF = 3×, µₛ = 0.6
2.256N
Force per clamp point (3 points)
0.7518N
Design Parameters
Orientation
vertical
Static friction (µₛ)
0.6000
Safety factor
3.000×
Design acceleration
1.000× g
Guidance
Low clamping force required. A light retaining ring or gravity with a lip may suffice. Using 3 clamp points provides good load distribution.
Abridged Optics — Clamping Force Calculator v1.0Assumes rigid contact. Does not account for thermal expansion or vibration fatigue.

All information, equations, and calculations have been compiled and verified to the best of our ability. For mission-critical applications, we recommend independent verification of all values. If you find an error, please let us know.