Hard and soft stepping is a way of changing the flex of a shaft in a club to obtain an in-between flex which will also produce a slightly different ball flight. It works the same way regardless if the shafts are taper or parallel tipped.
Depending on which way you go, a regular shaft can be made to feel a little firmer and a stiff shaft can be made to feel a little softer.
The most common practice is by removing all the shafts from your matching irons (3 iron through to PW) then put each shaft in either the following or proceeding club.
This is the process of making your clubs shaft a little more flexible. The 3iron shaft would be fitted into the 4iron head, the 4iron shaft into the 5iron head a so on. The 3iron would require a new shaft and the PW shaft would be left over. The effect on each club would be that each clubs shaft would be slightly softer than they were originally were and produce a slightly higher ball flight.
Tip: Moving shafts up one club.
This is the process of making your clubs shaft a little stiffer. The PW shaft would be fitted into the 9iron head, the 9iron shaft would fit into the 8iron and so on. The PW would require a new shaft and the 3iron shaft would be left over. The effect on each club would be that each clubs shaft would be a little bit stiffer than they originally were and produce a slightly lower ball flight.
Tip: Moving Shafts Down one club.
Remember, when you hard step, the club lengths will decrease. 3iron will become 4iron length, 4iron will become 5iron length and so on.
When you soft step, the club lengths will increase. PW will become 9iron
length, 9iron will become 8iron length and so on.
Adjustments will have to be made to the butt end of the shaft if you wish to keep the original clubs length.
"The main reason for soft or hard stepping is to change the feel of the shaft for golfers who really want their shafts to feel just right.
The second reason is to try to change the launch angle and trajectory of the shot or to reduce or increase spin.
A ½ inch can exhibit the beginning of a ‘feel’ difference. At an inch, some golfers who have a very consistent swing will start to notice some difference in launch angle and/or spin.
But in my experience, soft or hard is done far more for the purpose of image than for real performance purposes.