stan, the IR# is the tip trim designation that is listed on the trim chart in the catalog (the trim chart is in the front of the shaft section of the catalog. Page 123 of the first two catalogs we mailed this year. For the TX90, the designation is IR2. On the chart, the tip trim for a 5 iron for the TX90 is 2”. The trimming instructions are also on our web site.
Stan, Britt Lindsey from the GolfWorks sent over this response for me to post to you. I hope it helps, if not ask again.