Cutting insert, rotary tool, and method for manufacturing machined product

A rotary tool, comprising:

• a cutting insert;
• and
• a holder, wherein
• the cutting insert includes:
• a cutting portion that is located on a side of a first end of the cutting insert;
• and
• a shaft portion that is located on a side of a second end of the cutting insert,
• the cutting insert extends from the first end to the second end along a rotational axis,
• the cutting portion includes:
• a cutting edge that is located on the side of the first end,
• an end surface located on a side of the shaft portion, and
• a first through hole extending from the end surface toward the first end,
• the shaft portion extends from the end surface to the second end,
• the first through hole includes:
• a first opening that is located on the side of the first end, and
• a second opening that is located on the side of the shaft portion,
• the first opening is positioned in a rear of the second opening in a rotational direction of the rotational axis,
• the holder includes:
• a shank having a rod shape extending along the rotational axis, and
• a body extending along the rotational axis,
• the body includes a pocket that opens at a leading end of the body, and
• the cutting insert is configured to be attached to the pocket.

A rotary tool, comprising:

• a holder;
• and
• a cutting insert extending from a first end to a second end along a rotational axis, wherein
• the holder comprises
• a shank having a rod shape extending along the rotational axis, and
• a body extending along the rotational axis,
• the body comprises a first end surface at a leading end of the body, wherein a pocket is opening on the first end surface,
• the cutting insert is configured to be attached to the pocket,
• the cutting insert comprises
• a cutting portion that is located on a side of the first end of the cutting insert, and
• a shaft portion that is located on a side of the second end of the cutting insert,
• the cutting portion comprises
• a cutting edge that is located on the side of the first end,
• a second end surface configured to be in contact with the first end surface of the body, and
• a first through hole extending from the second end surface toward the first end,
• the shaft portion extends from the first end surface to the second end,
• the first through hole comprises
• a first opening that is located on the side of the first end, and
• a second opening that is located on the side of the shaft portion, and
• the first opening is positioned in a rear of the second opening in a rotational direction of the rotational axis.