Dynabolt brand Wowo M12 x 100 or Dynabolt Spikes, a type of bolt to be implanted in concrete. At the end of the bolt, the implanted part (bottom), generally has a larger diameter, until it finally shrinks to the bolt head (which has the nut). The bolt is also coated with a cylindrical sleeve, whose end (which is implanted into the concrete) has a slit in the direction of the bolt length. When dynabolt is planted into concrete, the nut will be tightened from the outer side of the concrete. the nut is tightened so that the end of the bolt tries to rise, thus opening the cylinder bolt sleeve. When these conditions occur, the silider sleeves that bloom, will cause a strong dynabolt in the concrete. In its development, dynabolt forms vary. Nails, Screws, Nuts and Bolts