To design a bolted joint, the transition bearing stress and maximumbearing stress have to be regarded. Transition bearing stress is thebearing stress where bearing failure begins and maximum bearing stressis where the joint goes to total failure. A method for studying rotationin a bolted joint has been developed using an optical instrument calledDigital Speckle Photography, DSP, which is a non-contact extensometerusing digital cameras, together with a load frame. The data from DSPsystem is transformed and analyzed to get rotations for different partsof the joint. Thinner joints give higher values on transition bearingstress, higher maximum bearing stress and higher maximum bolt rotation,than thicker joints. Bolt torque has a big impact and higher torquegives the same positive results as thinner joints. Increased secondarybending makes the joint more resistant to bearing failure, whichincreases the transition bearing failure stress, maximum bearing failurestress and maximum bolt rotation. There is a relationship between thecurve slope in a bearing stress versus bolt rotation figure and thetransition bearing stress. If the joint has a lower value on boltrotation, in comparison with other joints, at the same bearing stress,this will lead to a higher transition bearing stress.