(CNBC) Shares of industrial products maker 3M have been hit hard since the company’s disappointing first-quarter earnings report in April, and J.P. Morgan warned investors on Friday that there is more pain to come. J.P. Morgan analyst Stephen Tusa said in a note that 3M’s “premium valuation is unjustified by undifferentiated fundamentals,” with growth excluding mergers and acquisitions likely decelerating and benefits to margins fading.