An iron-type golf club having selectively machined portions and attributes, including a machined sole portion and/or a machined leading edge portion. The machined portion(s) include continuous machining scallop lines having a scallop height and a step-over distance.

An iron-type golf club head includes a heel, a toe, a top portion, a sole portion, a top portion, a rear portion, and a striking wall. The striking wall includes a striking face having a plurality of scorelines and a face center and a rear surface. A minimum striking wall thickness T min is no greater than 2.5 min. A thickened central region of the striking wall has a maximum thickness, T max, greater than T min but no greater than 2.75. A first thickness T1 of the striking wall corresponds with a first location spaced toe-ward from the face center by a first distance D1 of between 20 mm and 30 mm. A second thickness T2 of the striking wall corresponds with a second location spaced heel-ward from the face center by the first distance D1 such that T1 is greater than T2 by no less than 0.05 mm.

Some embodiments include a first golf club head and a second golf club head. The first golf club head includes a body having a face portion, and the second golf club head includes a body having a face portion. Meanwhile, the first club face portion comprises a face surface and at least one first club groove, and the second club face portion comprises a face surface and at least one second club groove. An edge radius of the first club head groove(s) can be less than an edge radius of the second club head groove(s), a base width of the first club head groove(s) can be less than a base width of the second club head groove(s), and/or a sidewall angle of the first club head groove(s) can be greater than a sidewall angle of the second club head groove(s). Other embodiments of related club heads and methods are also disclosed.

A golf club head including a striking face, a periphery portion surrounding and extending rearwards from the striking face, wherein the striking face comprises a front surface configured to strike a golf ball and a rear surface opposite the front surface, wherein the rear surface of the striking face comprises a supported region, a support arm spaced from the rear surface of the striking face, the support arm extending from the periphery portion towards the supported region, a deformable element residing between the support arm and the rear surface of the striking face, and wherein the deformable element comprises a front surface in contact with the rear surface of the striking face and a rear surface in contact with the support arm.

A golf club set includes golf clubs with different club numbers and loft angles. Each golf club head of golf clubs includes a crown portion, a face portion, and a sole portion. The sole portion includes a front region and a rear region, the front region being arranged on the face side, and the rear region being arranged on the back side. The front region has a flat front surface, and the rear region has a curved rear surface continuous with the front region. Among the golf clubs included in the golf club set, out of at least a pair of golf clubs having adjacent club numbers, the radius of curvature of the rear surface of the golf club having the higher club number is smaller than the radius of curvature of the rear surface of the golf club having the lower club number.

A golf club set includes a plurality of golf clubs having different loft angles. The plurality of golf clubs have the same lie angle. Each loft angle difference between two golf clubs that are adjacent in a loft angle order is the same. Each club length difference between two golf clubs that are adjacent in the loft angle order is 0.125 inches (3.175 mm) (inclusive) to 0.375 inches (9.525 mm) (inclusive). A loft angle of a golf club having a minimum frequency is smaller than a loft angle of a golf club having a maximum frequency. A difference between the minimum frequency and the maximum frequency is not less than 40 cpm.

The golf club set according to the present invention is a golf club set constituted by a plurality of numbered golf clubs with different loft angles. In each of the golf, a crown portion has a main body portion that connects to the sole portion and a raised portion that rises to form a step from the main body portion and extends in a toe-heel direction along a boundary with the face portion. In at least one pair of a lower numbered golf club and a higher numbered golf club, among the plurality of golf clubs included in the golf club set, a length of the step in a face-back direction along a perpendicular plane that passes through a sweet spot and a center of gravity of the golf club head is longer in the lower numbered golf club than in the higher numbered golf club.

A set of golf clubs having a degree of loft and lie adjustability to provide improved distance gapping.

A golf club training device including: a body having a first end configured to be gripped by a user and a second end longitudinally extended from the first end; and a swing speed sensor disposed at the second end for producing an output signal for determining a portion of a golf swing having a greatest swing speed. A golf club training system is also provided to include: a plurality of the golf club training devices wherein at least two of each of the plurality of golf club training devices having one or more of a different weight and length.

Some embodiments include a club head for adjusting vertical spin of a golf ball. Other embodiments of related systems and methods are also disclosed.