How to Machine a Steering Knuckle for Dump Trucks, Heavy Equipment, Earthmovers, and Large Vehicles in Mining and Construction

January 19, 2016  

Manufacturing some of the world’s largest vehicles and heavy equipment, dump trucks, earthmovers, and front-end loaders is big business.  And, it’s a tough business.  Vehicles must take hard hits and stay on track.

FERMAT’s top-of-the-line CNC horizontal boring mill with its strong, powerful headstock, spindle diameter of 130 mm, its sharply exact rotary table and ram travel of 900 mm (WFT 13 R,, was chosen by BELAZ, a manufacturer of truly gigantic hauling and earthmoving equipment, to machine components for its vehicles’ suspension systems.

Cutting and fashioning a cold slab of metal into a functional object, a reliable, durable component of heavy industrial machines can be trickier than you think.

Cutting and fashioning a cold slab of metal into a functional object, a reliable, durable component of heavy industrial machines can be trickier than you think.

FERMAT’s machine tools were tapped to create the humongous steering knuckles used with the front axle of its mammoth dump truck BELAZ-75306 and its modified versions

Despite being overlooked in trendy auto shows and encumbered with an ugly name, the steering knuckle remains one of the most important components in a vehicle’s suspension system.  In the huge BELAZ-75306 dump truck, the steering knuckle is the sturdy intermediary joining the gargantuan wheel with the rest of the automobile’s super-size suspension components.  The steering knuckle contains the wheel hub, onto which the tire assembly is attached, and into which the drive shaft and bearings are affixed.  Without strong, tough steering knuckles, BELAZ’s gigantic dump trucks would limp along and knuckle under to the strain and pressure, succumbing to the hard blows dealt to them, going the way of the woolly mammoths.  However, these giants are built to last, machined to perfection.

Thanks to their excellent design, power and precision, FERMAT’s machine tools smoothly mastered the task, creating the robust steering knuckles for BELAZ’s hauling and earthmoving equipment out of massive hunks of metal.  The process includes a variety of difficult machining techniques: side and face milling, drilling with a D 50 drill with inserts, helical milling, and counterboring.

Side and face milling allows for cutting long, deep slots in the workpiece, and the cutting tools can be compounded or configured to machine more than one surface in the same plane at the same time.  Drilling with a D 50 drill with inserts digs a large hole in the steel, a home for future bolts securing the component safely in place as the vehicle is shaken violently and tossed about.  Helical milling is a type of circular interpolation machining arcs and circles combined with linear interpolation during the same motion; while, counterboring is an interesting application reaching through holes drilled in the workpiece and cutting a seat for the head of the bolt, so it nestles flat against the surface of the component.

These adroit executions of CNC machining are captured in the following video, where FERMAT’s WFT 13 R creates a massive steering knuckle from crude steel:

Please visit our website,, for more information on FERMAT’s line of products that can help your manufacturing capabilities. Should you have any inquiries, please e-mail:, or call toll free: + 1-800-336-1262 or telephone: +1 (216) 451-5588