Free agency began in 1993, and while the Steelers have never been a team to rush to sign players right out of the gate, they definitely have found their share who have contributed to the success of the organization, including a few who helped bring a few more Lombardi Trophies to Pittsburgh.

So, with free agency now in full swing, it's time to take a look at five key free agent signings in Steelers history.

(Listed in alphabetical order)

Ryan Clark – Free Safety

The departure of one often times opens the door for another and that is what happened with the signing of Ryan Clark. Chris Hope departed after the 2005 season with a Super Bowl ring, and Clark was signed to take his spot at free safety in 2006.

Clark, who was an undrafted rookie in 2002 when he signed with the New York Giants, went on to start for the Washington Redskins in 2004-05, before signing with the Steelers. Once in Pittsburgh and teamed with strong safety Troy Polamalu his career flourished, finishing his career in Pittsburgh with 12 interceptions, six fumble recoveries, three forced fumbles, and two sacks.

James Farrior – Inside Linebacker

Farrior played 10 seasons for the Steelers after signing as a free agent in 2001 from the New York Jets. The Jets former No. 1 draft pick played in 154 games in Pittsburgh, with 30 sacks and 1,078 tackles.  

Farrior was a key component in the Steelers run to Super Bowl XL, in particular his performance against the Indianapolis Colts in the AFC Divisional playoffs when he recorded 10 tackles and 2.5 sacks.

Kevin Greene – Outside Linebacker

Kevin Greene was the second free agent ever signed by the Steelers, making the move from the Los Angeles Rams in 1993. In his three seasons with the Steelers he had 35.5 sacks and two Pro Bowl selections and was named AFC Linebacker of the Year by the NFLPA in 1994.

Greene, who left after the 1995 season, has been a finalist for the Pro Football Hall of Fame the last three years.

Just for the record linebacker Greg Clark was the first free agent signed and didn't last long, never playing for the team as he was released during training camp that year.

Jeff Hartings – Center

The center position is one steeped in tradition in Pittsburgh, with Hall of Famers Mike Webster and Dermontti Dawson setting the standard. So when Jeff Hartings signed with the Steelers in 2001 from the Detroit Lions, the pressure was on for him to live up to the standard.  

Hartings, a former No. 1 pick of the Lions who had only played guard, had blocked for a Pro Bowl running back in Detroit in Barry Sanders. When he came to Pittsburgh he moved to center and blocked for soon to be Hall of Fame inductee Jerome Bettis. And he did it in a way that would make his predecessors proud.

Kimo von Oelhoffen – Nose Tackle/Defensive End

When Kimo von Oelhoffen signed with the Steelers in 2000, he arrived as a nose tackle. After one season he was switched to defensive end, where his impact was felt immediately. He played six seasons with the Steelers, including 2005 when the Steelers won Super Bowl XL.

He started 94 of the 95 games he played for the Steelers, finishing his time in Pittsburgh with 229 tackles, 171 of them solo stops. He also had 20 ½ sacks, six fumble recoveries and two forced fumbles with the Steelers.