US Patent 10427278 Driving tool

A driving tool includes a coupling component defining a compartment and a driving component received by the compartment. The compartment includes a first receiving section and a second receiving section. The driving component includes a first driving body portion, a second driving body portion, and a connecting portion. The connecting portion is inserted through the first receiving section and is fixedly disposed in the second receiving section. The connecting portion and the second receiving section are forced into a tight interference fit with each other. The second driving body portion includes a length inserted and disposed in the first receiving section. The first and second driving body portions are made to have a first hardness, and the connecting portion is made to have a second hardness respectively. The second hardness is less than the first hardness.