Hard Surfacing: What Is It, and Why do I Need It?

You’ve heard them before…, “Bulldozers, Graders, Excavators, Backhoes. Words like these conjure up images of toughness and invincibility…, of endurance and cold hard steel. Without seeing it for yourself, you wouldn’t guess that massive machines would wear away from moving a bit of dirt around. After all, these are the tools that we use to move mountains, dam rivers, and level hundreds of acres at a time, right?

All true, but moving large amounts of material doesn’t mean that there isn’t a cost. Given enough time, even hardened steel wears away. The abrasiveness of that material, whether it’s soft loam, loose sand, or hard rock, will determine the speed at which your blades, buckets, and rakers will erode, but erode they will. Sometimes at an alarming rate, and operation-killing costs.

The way this problem is solved: Before a blade, bucket, tooth, or other object is used for the first time, welders are brought in and they lay down beads of very hard welding rod. These rods are special alloys that contain metals like manganese, molybdenum, and chrome. Each manufacturer makes them with a range of properties, including:

• Hardness (loamy soil only needs resistance to wear. but rocks require resistance to breakage AND wear)
• Strikability from any angle (some rods flow better when welding upside down)
• Penetration (or depth into the base metal)
• Machinability (some hard surfacing needs to be machined, or shaped, after being laid down)
• Slag Peeling (a cost-saving measure – the welding slag doesn’t have to be chipped afterward)
• Pilability (some rods pile high, while others flow out flat against the base metal)

You may have seen hard surfacing before – it’s usually laid down in cross-hatch patterns. However, welding hundreds of yards of rod is tedious, so you sometimes see that more creative welders will make all sorts of patterns and designs, in order to keep their day from getting too boring. The point is to build up the hard surface on all areas that will contact the material and to have it thick enough that it takes the main force of whatever is being pushed, dug, or cut.

How often this needs to be re-done depends on the material being rubbed across the hard surfacing, and the amount of time spent playing in the dirt. In bad conditions, it may need to be done several times a season. One thing is certain though, if a contact surface isn’t hard surfaced, you’ll be buying a new blade, bucket, etc. before very much time has passed.

All of this can be learned at places like ATS Heavy Equipment Training Schools before you ever set foot on a job site.