Piston housing body

A piston housing body comprising:

• a main body portion having at least a pair of piston housing portions for housing a pair of opposing pistons;
• an operating fluid circulation flow path for connecting the piston housing portions;
• and
• a connection portion for connecting an operating fluid supply flow path to the operating fluid circulation flow path, wherein
• the operating fluid circulation flow path is constituted by a pipe,
• both end portions of the pipe are cast in the main body portion, and an intermediate portion of the pipe and the connection portion are exposed outside the main body portion,
• a part of a cross section of the intermediate portion of the pipe is embedded in the main body portion, and a portion where flux applied to the pipe is melted and wetted is in close contact with the piston housing body, and
• an remaining part of the cross section of the intermediate portion of the pipe is exposed outside the main body portion.