The housing sector is so bad that it is affecting more than just home builders, Jim Cramer said on his "RealMoney" radio show Friday. People are selling off companies such as Caterpillar ( CAT), Foster Wheeler ( FWLT)and Ingersoll-Rand ( IR), the latter of the two which Cramer owns for his charitable trust, Action Alerts PLUS . This, Cramer said, doesn't make any sense. Though the infrastructure business, which is involved with the large petrochemical plants, is red hot, these stocks are going down because they're all being lumped together with housing even though they shouldn't be, he said. If at all, a very small percentage of these companies is in housing, he said, adding that this is very discouraging for holders of these stocks. Last Friday Cramer said he issued an alert to his Action Alert PLUS subscribers that people should declare victory with Halliburton ( HAL) and sell it when it was at $37, even though Cramer could not sell it for his charitable trust, Action Alerts PLUS . From last Friday, the stock is down seven points. This is a company that has lost $8 billion in market capitalization even though Halliburton reported an earnings report that was great, Cramer said. People are now starting to make up things to make some rational sense out of this irrational behavior, Cramer said. But don't listen to the headlines. The fact of the matter is that the infrastructure business is really strong, and it is not connected to housing, Cramer said. In the meantime, Cramer told listeners to wait for sellers to give up and throw away the stocks, and then pick them up. "Let them do their silly selling and create the bargains for us," he said. "Wait until the sellers have made fools of themselves and then walk in." Cramer advised people to look at Caterpillar and the railroad sector, which he said are bellwethers for the economy. Recently CAT came out with a great report, which reminded him of United Technologies ( UTX), a company that Cramer also owns for his charitable trust, Action Alerts PLUS . Both companies are saying that there is about four or five years of growth ahead. This is because they both have gigantic orders, he said. Caterpillar sells trucks for mining, commercial construction and road building. These are big businesses that have nothing to do with consumer spending, Cramer said. People should read reports and not just sell, he said, adding that if people have patience the stocks will come back. "It's just too nutty right now." To see the most recent edition of The RealMoney Radio Recap in its entirety, please click here. This recap is published every day around 3 p.m. ET.