Square hole found many applications in various areas like wood, marble and metal work for different purposes. There are many methods available to make square hole as discussed in this work. But making a square hole with drill operation is a different concept as in this concept reuleaux triangle type cam is used to make a square hole. But with using this type of cam we can produce almost square hole not exact square hole because there is left a fillet radius on each corner of square which required further operation. To overcome these problem different types of modified cam geometry of reuleaux triangle are introduced in this work.