Power tool having rotary hammer mechanism

A power tool comprising:

• a rotary hammer mechanism configured to produce (i) hammering motion for driving a tool accessory along a driving axis and (ii) rotating motion for rotating the tool accessory around the driving axis;
• a striking element configured to transmit the hammering motion to the tool accessory by moving along the driving axis and colliding with the tool accessory;
• and
• a tool holder having (i) a tubular wall (a) with a longitudinal central axis that is co-axial with the driving axis and (b) configured to removably hold the tool accessory and (ii) a rotation transmitting part configured to transmit rotating power to the tool accessory, wherein
• a layer of carbide of a group 5 element of a periodic table is on the rotation transmitting part,
• the tubular wall and the rotation transmitting part are of a same material and one-piece,
• the tubular wall includes (i) a large diameter part configured to slidably house at least a portion of the striking element and (ii) a small diameter part having a smaller inner diameter than the large diameter part,
• the large diameter part and the small diameter part do not overlap in radial and circumferential directions,
• the rotation transmitting part is in the small diameter part, and
• an inner peripheral surface of the large diameter part has a lower surface roughness than an inner peripheral surface of the small diameter part.