There is a variety of “Preset” and “Adjustable” torque screwdrivers, but selecting the correct hand screwdriver for you application depends on your objective. Preset torque screwdrivers offer tamper-proof operation, while adjustable screwdrivers offer different setting options for applications that require more than one torque value.
A preset torque screwdriver is similar to a person setting an alarm clock to signal the achievement of a selected time. The torque screwdriver is pre-set to the required torque value of the application and then the tool signals the operator when torque is achieved. A preset torque screwdriver does not feature an external adjustment scale. These tools have internal adjustment mechanism for setting the torque value and must be preset using a torque tester. The preset screwdrivers are ideal for production applications where there is one torque setting required and you need to prevent incidental or operator tampering of the torque setting. However, if the torque specification changes or new project requires a different torque setting, the preset torque screwdriver is still flexible enough that a new torque setting can be set internally using a torque analyzer.
Adjustable torque screwdrivers offer different setting options for applications that require more than one torque value. The adjustable screwdriver does feature an external adjustment scale, which allows for an operator to adjust the torque setting as needed for the application. A quality adjustable screwdriver typically features a ring or bezel device that allows an operator to press down to adjust the torque setting and then locks into place once released preventing incidental torque adjustment. These tools are ideal for field service or production applications as the adjustable torque screwdriver provides manufacturers with flexibility.