Camschaft for internal combustion engine

A camshaft for an internal combustion engine, integrally comprising:

• a shaft main portion that extends linearly;
• a plurality of valve-actuating cams disposed to be spaced apart from each other in an axial direction of the shaft main portion;
• a pair of support arms extending along one diametric line of the shaft main portion radially outwardly from one end part of the shaft main portion and being fitted with a follower rotational body for transmitting a rotational power to the shaft main portion;
• and
• a pair of overhangs integrated with the shaft main portion and the pair of support arms, the overhangs extending between the support arms in a peripheral direction of the shaft main portion,
• wherein a thick-wall portion having a larger thickness in a direction along an axis of the shaft main portion is formed in part, on a radially outer side of the shaft main portion, of each of the overhangs, and
• wherein the overhangs each include a boss portion that connects base end portions of the pair of support arms, the thick-wall portion, and a thin-wall portion that has a smaller thickness in the direction along the axis of the shaft main portion than thicknesses of the boss portion and the thick-wall portion and that connects the boss portion with the thick-wall portion.