The Blades dominated the top v second clash but had to settle for a point.
Billy Sharp's 21st goal of the campaign cancelled out Paddy Madden's effort as the Blades and Scunthorpe drew once more.
Manager Wilder freshened up his starting XI once again, making a total of four changes, bringing back skipper Sharp, Hanson, Duffy and Freeman. Riley, O'Shea, Done, Lavery dropped to the bench.
Aided by a boisterous large crowd, it was an intense start with United looking to apply the early pressure. Just 85 seconds had elapsed when a quick throw saw Sharp side-foot over a Lafferty cross. Another quick set-piece, on seven minutes, saw Duffy shoot wide when in the clear after linking up with the Blades captain.
Scunthorpe were clearly operating a pressing game early on and United were seeing more of the ball. Hanson connected with a Lafferty cross but a deflection helped Daniels to make a save.
As the half wore on, United's chances dried up, despite continuing to be on top. The first Scunthorpe chance saw Dawson drag a shot wide after controlling a pass from Sutton.
Wallace took the ball off Sharp's head and Mirfin blocked a Lafferty shot as United stayed on the offensive. The final chance of the half arrived on 41 minutes with Hanson meeting Duffy's cross but Daniels made a comfortable save.
United's dominance of the first half earned a warm reception from the Blades fans at the half-time whistle but two minutes into the second half the mood changed as Scunthorpe netted. Dawson's low cross squirmed across the face of goal where MADDEN was waiting to beat Moore.
Celebrations ensued but the visiting side's lead lasted less than two minutes. Freeman got around the back of the defence, his cross was half cleared but Fleck lifted back into the danger area where Hanson got a touch before Sharp half-volleyed into the corner of the net.
Two minutes later Scunthorpe were reduced to ten men. Toffolo, booked on ten minutes, had already committed two more fouls before clearly obstructing Freeman. Referee Jones produced a second yellow before the inevitable red.
Four of the next five Blades chances fell to Fleck. Two were blocked by Mirfin and one by Dawson, whilst he blasted one just over the crossbar after patient build up by Freeman and Duffy. In between these chances, Lafferty drilled an effort wide.
As the final ten minutes approached, Wilder changed the tactics, throwing on Lavery for Hanson, soon after O'Shea took the place of Lafferty. In between these changes Mirfin crowded out Lavery and from the resulting corner Sharp failed to turn in Fleck's delivery, the ball agonisingly creeping the wrong side of the post.
Scunthorpe were still a threat, emphasised on 88 minutes. Substitute Mantom attacked down the left and from his cross, Madden turned the ball onto the near post before the Blades cleared.
Five minutes added time was announced and the woodwork was struck again. This time Freeman, Lavery and Fleck linked up but O'Shea's effort struck a post and rebounded into the grateful arms of goalkeeper Daniels.
Wilder attempted one more brave move, replacing defender O'Connell with striker Done, but there were no further chances as both sides collected a point.
Blades: Moore, Fleck, O'Connell (Done 90), Basham, Sharp, Wright, Coutts, Hanson (Lavery 79), Freeman, Duffy, Lafferty (O'Shea 84).
Unused: Long, Riley, Ebanks-Landell, Carruthers.
Scunthorpe: Daniels, Wallace, Mirfin, Dawson, Madden (Davies 90), van Veen (Hopper 71), Morris, Bishop, Toffolo, Crooks (Mantom 78), Sutton.
Unused: Anyon, Holmes, Goode, Toney.