Golf club head with adjustable fitting mechanisms

A putter-type golf club head comprising:

• a club head body comprising a toe end;
• a heel end;
• a top rail;
• a sole;
• a front striking surface;
• and a rear surface spaced from the front striking surface;
• wherein the rear surface, the sole, and the top rail defines a recess;
• a hosel comprising a hosel arm and a loft arm;
• wherein:
• the hosel arm comprises a hosel arm first end, a hosel arm second end, and a hosel body;
• and
• the loft arm comprises a loft arm first end and a loft arm second end;
• and
• a fastener;
• wherein:
• the loft arm is configured to couple to a golf shaft;
• the hosel arm extends generally in a top rail-to-sole direction;
• the hosel arm and the loft arm are pivotably engaged to one another below the top rail of the club head body at the hosel arm second end and the loft arm second end, and are configured to incrementally change a loft angle of the putter-type golf club head;
• the loft angle is incrementally adjustable to angles less than 10 degrees;
• the loft arm first end forms a loft arm middle aperture and a plurality of loft arm top apertures, both positioned closer to the loft arm first end than the loft arm second end;
• the hosel arm forms a hosel arm mounting aperture and at least one plunger aperture, both positioned closer to the hosel arm first end than the hosel arm second end;
• at least one spring plunger is secured into the at least one plunger aperture and engages the plurality of loft arm top apertures;
• the loft arm middle aperture and the hosel arm mounting aperture receive the fastener;
• and
• the fastener allows adjustment of the loft angle by releasably securing the hosel arm and the loft arm;
• wherein:
• the loft arm second end forms a loft arm lower aperture;
• the hosel arm second end forms a hosel arm lower mounting aperture;
• a bolt pivotably couples the loft arm and the hosel arm by extending through the loft arm lower aperture and the hosel arm lower mounting aperture;
• and
• an arrangement of the bolt, the hosel arm, and the loft arm allows the loft arm to rotate in a front striking surface-to-rear surface direction, to adjust the loft angle, and
• the loft arm lower aperture is a counterbore;
• wherein the counterbore provides an abutment surface for a bearing.