Robotic peg-hole insertion operations can play a very important role in manufacturing industry because it is a common requirement in the manufacturing process and, it requires high precision and high speed. In general, this operation can be divided into two processes: Search process to engage the peg and the hole and, insertion process. The search process is critical in the assembly operation. It can be defined as a process where the angular and the translational errors between the peg and the hole are reduced until insertion can occur. In this paper, a theoretic model of the search process without a chamfer has been presented. The aim of study was to identify the basic relationships betwen the inputs to the peg-hole system, the movement of the peg and the contact forces between the peg and the hole. Additionally, an equivalent model has been established. From this study, a simple new search strategy has been developed and proven in simulations and experiments.