This is a quick reference chart to compare the 'stiffness' of Dynamic Gold vs. Project X vs. KBS Tour.
Since there's no industry standard for Regular/Stiff/X-Stiff iron shafts, this is a quick and easy way to compare shafts.
DGS300 = Dynamic Gold S300
PX = Project X
FCM = The old Rifle scale of measuring shaft stiffness
SS = Soft Stepped - putting a 8 iron shaft into a 9 iron head and trimming to 9 iron length
SSx2 = Soft Stepped twice - (putting an 7 iron shaft into a 9 iron head and trimming to 9 iron length
HS = Hard Stepped - putting a 8 iron shaft into a 7 iron head and trimming to 7 iron length
HSx2 = Hard Stepped twice - putting a 9 iron shaft into a 7 iron head and trimming to 7 iron length
Each full flex is roughly 3 soft/hard steps.