(From left to right: Tory, Grant, Kari, Adam & Jamie)
Hyneman and Savage are assisted by others, most notably Hyneman's M5 Industries staff, collectively known as "The Build Team".
This staff has appeared onscreen since the second season and were given equal billing with Hyneman and Savage during the third season. Staff members have included M5 alumnus Salvatore "Tory" Belleci, Kari Byron, metal worker and welder Scottie Chapman, electrical engineer Grant Imahara, and Discovery Channel contest winner Christine Chamberlain (often referred to as the "Mythtern," a portmanteau of "myth" and "intern").
The program originally featured interviews with folklorist Heather Joseph-Witham, who explained the origins of certain urban legends, and people with first-hand experience of claims being tested. This was phased out by the third season to focus more on the experimentation process. (The only experts shown now are consultants who interact directly with the cast during testing.)
Much of the show's appeal comes from the interaction between Savage and Hyneman, which is similar to a double act, wherein Hyneman plays the straight man and Savage is the comic foil/relief.