3M--- not that it makes a whit of difference in the long run, curiosity caused me to pursue IBD's sectors. It groups 3M in "misc" along with the likes of BRK, DD, GE, HON, SI, ETN, ITT,
TYC and a host of others.
IBD also carried an ad for SPDR sector ETFs where 3M is found in XLI--Industrial along with GE, UTX, CAT, BA, HON, EMR and others. The sector XLB--Materials lists MON, DD, DOW, LYB, PX, FCX, IP, PPG and others, but not 3M.