Fastening tool

A fastening tool comprising:

• a bit holding unit having a holder configured to hold a driver bit so as to be rotatable and to be movable in an axial direction;
• a first drive unit having a first motor configured to rotate the driver bit held on the holder by the bit holding unit;
• a second drive unit having a second motor different from the first motor, the second motor configured to move the driver bit in the axial direction in a forward direction and a reverse direction;
• and
• a controller configured to control a movement distance of the driver bit in the axial direction relative to a starting position of the driver bit by controlling an amount of rotation of the second motor,
• wherein the controller is configured to:
• synchronize a screw fastening operation, in which the driver bit rotates and drives a screw into a fastening target, with an operation of the second motor for moving the driver bit in a forward direction along the axial direction, by determining at least one of:
• a load applied to the first motor, a rotation speed of the first motor, a load applied to the second motor, and a rotation speed of the second motor;
• adjust the movement distance of the driver bit along the axial direction to follow the amount of movement of the screw fastened into the fastening target based on the determined load and rotation speed;
• and
• control the amount of rotation of the second motor to stop the driver bit at a predetermined stop position during the fastening operation.