While we can quibble back and forth about our favorite rod ends and what we think the strongest joints are built with, one stand-alone joint is unarguably in a class by itself. EMF Rod Ends & Steering Components has been making numerous EMF rod end designs (for various applications) for over 10 years now, and they can easily take home the trophy for the strongest and most failure-resistant joints made.
EMF joints are machined from solid stock 4140 HTSR -- a material with a tensile of 144,000 pounds and a yield of 128,000 pounds. It has a high wear resistance, excellent toughness, and good ductility. While other materials have similar or higher tensile strengths, the toughness of this material is what ensures you will never be stranded with a broken joint. It can rapidly distribute both the stress and strain within itself caused by a suddenly applied load. Simply put, the material has the ability to withstand some major shock loading instead of having a brittleness that might allow sudden failure. Without naming any other rod end brands specifically, EMF tells us that others’ high-end rod ends have little resistance to failure once the elastic point of the material is reached, whereas the EMF joints will bend instead of breaking. And you can still make it home with a bent rod end, as opposed to the potential for disastrous consequences should a rod end break.
Breaking tradition with design, EMF went with a wider head. The purpose was for the largest cross-sectional area possible. With the extra head width, EMF was able to incorporate an integral race land. This land totally prevents the ball and race from ever leaving that side of the body. This is an invaluable feature for a joint being used in a single shear application. With the land placed between the ball and mount, it’s impossible for the joint to leave the ball. Traditional joints require safety washers, and the ball of a 1.25-inch traditional joint can leave the housing with five tons of pressure.
The other side of the EMF joint has a spiral lock and spanner ring. This side allows you to adjust the play between the ball and races. In tests, EMF began to see damage to the ring in side-loading applications at approximately 85,000 pounds. The spiral lock helps keep the race from clocking the spanner ring out from friction. What is the benefit with an adjustable joint? When you’re on the trail or at an event, you can tighten the joint and remove damaging play.
On top of all that, the EMF joint is ultra-versatile. The ability to remove the races and ball for rebuilding and maintenance purposes also allows you to change the ball in the joint. EMF has the largest variety of balls of any joint company in the world. Instead of making one generic ball and using misalignment spacers, EMF uses misalignment integral balls and a wide variety of hole diameters and widths, allowing an average of 27 degrees deflection or 54 degrees combined. Straight pins, threaded pins, and tapered pins are integrated into the ball, eliminating seams in the ball and slop between the hole ID (inner diameter) and bolt OD (outer diameter).
EMF’s joints are made in a 5/8-inch size all the way up a 2-inch Frankenheim joint many times stronger than anything you’ll ever need.