Wheel bearing for part-time four-wheel drive vehicle

A wheel bearing (100) for a part-time four-wheel drive vehicle capable of switching between a two-wheel drive mode and a four-wheel drive mode, comprising:

• a wheel hub (200) to which a vehicle wheel is mounted and which rotates together with the vehicle wheel;
• at least one inner ring (300) mounted to the wheel hub (200);
• an outer ring (400) fixedly coupled to a vehicle-body-side member;
• a plurality of rolling elements (500) configured to rotatably support the wheel hub (200) and the inner ring (300) relative to the outer ring (400);
• and
• a coupler (600) mounted to the wheel hub (200),
• wherein the coupler (600) comprises outer circumferential surface splines (630) extending in an axial direction on an outer circumferential surface thereof, and
• wherein the outer circumferential surface splines (630) of the coupler (600) are configured such that a hardening heat treatment is performed at least on a portion that is engaged with a clutch member.