On Wednesday's episode of "Mad Money," Jim Cramer spoke with Airgas ( ARG) CEO Peter McCausland. In October, Cramer named Airgas a sell, but he said he was wrong, since the stock was up 37% since.

Cramer said last night that he's "sticking" with McCausland. On Thursday, Airgas closed down 25 cents to $42.72.

Cramer's Wednesday "Tech Spec" picks was Cadence Design Systems ( CDNS), which he said could follow Taiwan Semiconductor's ( TSM) 27% rise since he'd last recommended that stock.

Cramer said Cadence doesn't have much competition in its business of making tools that help create smaller, faster microchips. He said its management made big mistakes in 2008, but that's all in the past, and the company has a new chairman and CFO who's been buying shares.

On Thursday, Cadence added 28 cents, or 5%, to close at $5.88. Taiwan Semiconductor gave up 66 cents, or 6%, to close at $10.39.

In the "Lightning Round" segment, Cramer he would buy Waste Management ( WMI). He liked the stock's 4% dividend.

Waste Management closed down 30 cents, or 1.1%, at $26.65 on Thursday.

Cramer also said that DryShips ( DRYS) is a speculative play in its group. He recommended Frontline ( FRO) and Nordic American Tanker ( NAT) instead.

On Thursday, DryShips closed down 66 cents, or 6.2%, at $10.04. Frontline dropped 90 cents, or 3.7%, to $23.73, while Nordic American Tanker was down 50 cents, or 1.4%, to $36.22.
At the time of publication, Cramer had no positions in stocks mentioned.

Jim Cramer is a director and co-founder of TheStreet.com. He contributes daily market commentary for TheStreet.com's sites and serves as an adviser to the company's CEO. Outside contributing columnists for TheStreet.com and RealMoney.com, including Cramer, may, from time to time, write about stocks in which they have a position. In such cases, appropriate disclosure is made. To see his personal portfolio and find out what trades Cramer will make before he makes them, sign up for Action Alerts PLUS. Watch Cramer on "Mad Money" weeknights on CNBC. Click here to order Cramer's latest book, "Mad Money: Watch TV, Get Rich," click here to order his book, "Real Money: Sane Investing in an Insane World," click here to get his second book, "You Got Screwed!" and click here to order Cramer's autobiography, "Confessions of a Street Addict." While he cannot provide personalized investment advice or recommendations, he invites you to send comments on his column by clicking here.

TheStreet.com has a revenue-sharing relationship with Traders' Library under which it receives a portion of the revenue from Traders' Library purchases by customers directed there from TheStreet.com.

If you liked this article you might like

Adobe Systems, Salesforce.com, Cummins: 'Mad Money' Lightning Round

The Kids Are Taking Over the World: Cramer's 'Mad Money' Recap (Thursday 5/11/17)

DryShips Stock Rises After Paying Off its Commercial Loan Facility

Matson Buyers Will Have to Be Patient

How to Play a Challenging and Rising DryShips