If you swap 3 into 4, 4 into 5 etc, does it move the flex one point, ie stiff to reg?

iron shafts are tip trimmed differently to allow for the increased size and weight of the heads as you get higher in loft,ie 1/2" for the 3 iron,1" 4 iron etc etc until you get to the wedge.However the wedge will not be fully trimmed because the shaft would be to stiff for shorter shots where you don't fully load the shaft,this is why you get 'wedge flex',which as far as I know is just a shorter trim.

Anyway,to answer your question,er,I don't know:) But considering you will have a 3 iron shaft with a 4 iron head I assume it will play shofter,this may not be the same as just saying it will play regular,it may do though.I doubt it will be one full flex point ,but someone with more knowledge than me may know.

Firstly this is only easily do-able if the shafts are parallel tip rather than taper, but most are. Using a set of DG S300 shaft blanks the standard trimming instructions are for a 1 iron don't tip trim. For the 2-iron through to the 9 iron you tip trim 1/2 inch per club. EG 0.5 inches for a 2 iron and 4 inches for a 9 iron, then it goes to 4.25 inches for a wedge. You then get the finished length by trimming from the butt end. In an off the shelf set the variance between clubs will normally be 1/2 an inch in length and 7 grammes of head weight.

When trimming the tip section you have the option to follow the standard instructions or you can take more or less off than recommended. This is known as hard or soft stepping and allows you to get flexes either slightly stronger or weaker than those achieved by standard installation.

In your specific question putting a 3 iron shaft into the 4 iron head will soften the flex and increase the swingweight, the 4 iron head should be approx 7 grammes heavier. If you then butt trim the shaft back to 4 iron length, ie 1/2 inch off, then you will reduce the swingweight and increase the stiffness. But it will still play more flexible than the original set up. I would say you would end up with almost a half flex weaker.

The only way to really do this is by trial and error. Thankfully DG blanks are pretty cheap and I find no problem taking heads on and off until I'm happy. If you are trying with graphite then you really need some knowledge and a shaft puller. This is becasue the heat used to break the epoxy seal can also break down the bond stability in the graphite shaft. The puller will apply steady pressure so that the head comes free with out overheating to the point where the shaft breaks down.

MacBludgeon
Thanks for the reply.
I have Dg S300 in my mp37s, but would like them 1/2" longer(hand hangs of grip) and thought this is a good way to do it.

Plus think a flex between S and R would be better for me, as long as its not softer than R. Can keep the grips on as well and only need to buy 1 shaft.

Might try it with 4 and 5 iron, as dont use the 4 much.

Going to have to stop tinkering with clubs ;o)

You could always put an extension on each iron yourself,will cost you a few quid for the extensions and the price of new grips.The extra length will effectively soften the flex a tad.