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) - Get Report

, which he said could follow

Taiwan Semiconductor's

(TSM) - Get Report

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) - Get Report

is a speculative play in its group. He recommended

Frontline

(FRO) - Get Report

and

Nordic American Tanker

(NAT) - Get Report

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

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