Slaker Screw Repair

CMW Global completed a precision repair and hardfacing upgrade on a 20″ x 27′ slaker grit conveyor screw for a pulp and paper mill in the Southeast. By diagnosing the root cause of premature flight wear and applying targeted hardfacing, CMW restored the stainless steel screw to full OEM specs while significantly extending its future service life.

304 SS

Shaft and Flight Material

20"

Diameter

27'

Length

58-61Rc

Hardness in One Pass

Challenge:

Lime slakers in pulp and paper mills rely on specialized screw conveyors to extract, wash, and dewater the heavy, abrasive grit produced during the causticizing process. The rotating flights lift settled grit upward while water drains back through the system — but constant exposure to abrasive material and highly alkaline slurry wears down the flights over time. This screw needed to be restored to its original specs — 20″ diameter, 27′ long, 40 left-hand flights — without sacrificing long-term durability.

Solution:

CMW Global rebuilt the screw using 304 stainless steel for the shaft and flights, matching the corrosion resistance the alkaline environment demands. To stand up to constant abrasion, our team applied welded hardfacing to the flight edges — an iron-based alloy with a chromium carbide matrix reaching 58-61 Rc hardness in a single pass. The rebuilt screw was restored to full original dimensions and flight count, with correct left-hand orientation maintained, ready to return to service.,

Before

After

Ready to Extend the Service Life of Equipment?

Don’t let unexpected failures slow down your operations. From precision weld hardfacing to complete 304 SS shaft and flight rebuilds, CMW Global delivers quick turnarounds and industrial wear protection built for pulp and paper mills.