| Time | Date | Name | Meet |
|---|---|---|---|
| 45.60 | Dec. 6, 2014 | grant betulius | Hawkeye Invitational |
| 46.33 | March 28, 2013 | grant betulius | NCAA Division I Mens Championships |
| 46.70 | March 1, 2013 | grant betulius | Big Ten Conference Mens Championships |
| 46.76 | Feb. 28, 2013 | grant betulius | Big Ten Conference Mens Championships |
| 46.97 | Dec. 1, 2012 | grant betulius | Iowa Invitational |
| 47.17 | Feb. 23, 2012 | grant betulius | Big Ten Conference Mens Championships |
| 47.65 | Dec. 3, 2011 | grant betulius | Hawkeye Invitational |
| 48.55 | Dec. 2, 2011 | Dustin Rhoads | Hawkeye Invitational |
| 48.75 | Feb. 26, 2010 | Max Dittmer | Big Ten Men's Championships |
| 48.86 | Feb. 25, 2010 | Max Dittmer | Big Ten Men's Championships |
| 49.41 | Feb. 26, 2009 | Max Dittmer | Big Ten Championships (Men) - Day Two - Prelims |
| 50.15 | Dec. 6, 2008 | Max Dittmer | Mizzou Invitational |
| 50.63 | Oct. 17, 2008 | Max Dittmer | Wisconsin @Iowa |
