Whether you use 1/2″, 3/4″ or 1″ EMT, keeping HVAC ductwork quiet is reliably cost-effective and easy with the Iowa Precision Tie Rod Crimper. Using commonly available hardware, this machine crimps hex-bolts or hex-nuts into the tie rod end tight enough to survive a 3,000 lbs. Pull Test. Changeover from inserting hex-bolts to hex-nuts takes just a few seconds. Rubber grommets prevent air leaks, vibration and noise. We are proud to carry Iowa Precision Tie-Rod installation products here at H. Weiss.