An intraosseous needle assembly includes a needle having a first cylindrical shaft. The shaft having a distal end, a proximal end, and a wall defining an inner channel. The first cylindrical shaft includes threading protruding from the wall along a proximal portion of the first cylindrical shaft. The needle further includes a needle head extending from the proximal end of the first cylindrical shaft. The needle assembly may further include a stylet, the stylet having a second cylindrical shaft having a first end and a second end and a stylet head extending from the second end. The stylet head includes a proximal surface and a distal surface, a pair substantially parallel second side walls, a pair of rounded end sections joining the second side walls, a protrusion extending from the distal surface, and a tapered section extending from the distal surface to the second cylindrical shaft.
