Clad plate

A clad plate comprising:

• an aluminum plate made of an aluminum material;
• a nickel layer;
• and
• a hard metal plate made of a copper material;
• wherein
• a side end surface of the aluminum plate, the nickel layer, and a side end surface of the hard metal plate are joined together in this sequence by a pressure weld;
• the aluminum plate includes a ridge and a groove extending from a front end side to a rear end side in the side end surface thereof and the hard metal plate includes a groove and a ridge extending from a rear end side to a front end side in the side end surface thereof, with the ridge and groove of the aluminum plate being respectively engaged and jointed, via the nickel layer, to the groove and ridge of the hard metal plate;
• and
• the nickel layer includes an end portion that is jointed to a surface of the aluminum plate, the end portion of the nickel layer extending beyond the rear end portion of the side end surface of the aluminum plate and being exposed on the surface thereof, and an average width of the end portion of the nickel layer exposed on the surface of the aluminum plate being in a range from about 0.2 mm to about 1.5 mm.