If you get all 100 ingots and turn them in at the same time, the equipment you acquire actually weighs more than the 100 ingots. If all received at once they have a weight of 128. So it would be wise to find a hiding place for your loot (such as Midea's desk) until you plan to head back to the Wasteland, and especially before you head into the Hole at the end of the Unsafe Working Conditions quest. On top of the rewards from this quest (if you keep them in your inventory) you will receive all the equipment that was taken from you upon entering the Pitt and will likely become over-encumbered.
Once you have collected all 100 ingots, Everett will say "Yup, guess you got every last one out there. You're one hell of a steeler, kid." "Steeler" is a common name for a worker in a steel yard and is also the name of Pittsburgh's NFL football team.
When giving you the Mauler, Everett notes that he had killed trogs and ghouls with it "from here to Monroeville." Monroeville, Pennsylvania is the city where Pittsburgh native George A. Romero filmed the classic 1978 horror film Dawn of the Dead.
ps3 In some cases Everett won't go into the mill where you have to give him the ingots, preventing you from finishing the quest. In this case, just keep the ingots you've collected and advance through the storyline. After you defeat everyone in the Hole, return to Everett and he'll congratulate you. At that point, his conversation options will return to normal, and you can exchange your remaining ingots. [verified]
ps3xbox360 If the last few ingots are presented in a quantity less than 10, you may not get the achievement, nor the equipment. [verified]
pcxbox360 When on the building which has 12 ingots, it is possible to fall through the roof straight to the ground which kills you instantly. This bug occurs if Point Lookout has been installed. A solution is to save the game while on the roof, restart and load the save. When you enter to another area through a door, you have to restart the game again. [verified]
ps3 Although Wild Bill's body may be looted after falling through the normally accessible map (see here), the two ingots normally present next to his body will not be found, thereby making the achievement or trophy impossible to get, and limiting the maximum obtainable ingots to 98. [verified]