A clamp has a hemispherical contact face of radius R = 10mm to allow for misorientation. It is used to clamp a heavy lead archaeological treasure for X-ray examination. How much clamping force, F, can be applied without damage (meaning plastic deformation) to the treasured object? You will find the both the modulus E and yield strength  of lead alloys in Appendix A, Table A3 (use mean values), and the equation for force required to trigger plastic deformation beneath a spherical indenter in Appendix B, Table B8.

Data From Table A3

Data From Appendix B8