TO FRICTION-FIT (press-fit)

To friction-fit (or to press-fit) is the action of assembling two components by force-fitting one into the other. Typically, a slightly conical part is driven into a corresponding hole. In watchmaking, this method is used to fit pins and tenons into the mainplate, to secure jewels into the plate and bridges, or to mount hands onto their respective canon pinions or staffs. Although the operation can be carried out in various ways, it is most commonly performed using a micrometric staking tool. A successful press-fit requires perfectly matched components to ensure a secure and precise assembly.