Barrel block for twin-screw extruder and twin-screw extruder

A barrel block for a twin-screw extruder, the barrel block that constitutes a barrel and includes joints at both ends, the barrel including a cylinder that rotatably houses two screws, the barrel block comprising:

• a block body of a rectangular parallelepiped shape that includes a first block end face, a second block end face opposite the first block end face, and four block side faces that connect the first block end face and the second block end face;
• a first flange of a rectangular frame shape that projects toward an outer periphery from an outer peripheral edge of the first block end face;
• a second flange of a rectangular frame shape that projects toward an outer periphery from an outer peripheral edge of the second block end face;
• a plurality of first bolt holes formed in the first flange with spacing, and a plurality of second bolt holes formed in the second flange with spacing, the first and second bolt holes that surround the block body;
• and
• a cylinder part that passes the block body straight from the first block end face to the second block end face and defines an insertion hole for the screws, wherein
• the first block end face and an end face of the first flange forms a first joint, and
• the first joint includes
• a first inner joint face that continuously surrounds a peripheral edge of the insertion hole for the screws,
• a first flank face that is recessed from the outer periphery of the first inner joint face toward the second block end face, and
• a first outer joint face that is located at a tip of a first projection that projects from the first flank face in the outer periphery of the first bolt holes, and
• the first outer joint face is more recessed toward the second block end face than the first inner joint face.