Heat Treatment of “Rockbreaker” Steel Tools

Rockbreaker Tools Prior to Oil Quenching

“Rockbreaker” is a trade name for a steel hydraulic hammer tool used in the construction, mining, quarrying and demolition industries to literally break rock and concrete. The name is owned by “Caldervale Group Ltd”., of Airdrie, Scotland who manufacturers and ships the tools around the world with North America being their largest market.
 
“All Rockbreaker steel tools are manufactured from top quality steels, machined and heat treated in the company’s own production facilities in Calderdale, Airdrie ensuring that each breaker tool has the consistent impact, strength, hardness and ductility needed in the rugged conditions experienced in the construction, mining, quarrying and demolition industries.
 
Rockbreaker Steels are totally manufactured under a strict quality control management system certified to British Standard BS EN ISO 9001, 2008 ensuring the production of superior quality breaker steels. We are committed to research and development as an integral part of our existence to produce the world’s finest most versatile hydraulic breaker steels deserving the world-wide earned reputation. Continual improvement in process`s and procedures.”
 

Rockbreaker Tools Prior to Heat Treatment

Monday November 10th, “Gord Montgomery” of “The Monty Heat Treat News”  had the privilege of a guided tour of the facility, courtesy of Mr. Jim Hamilton, Technical & Sale Manager for the company.
 
This being our first experience with hydraulic hammer tools we weren’t entirely sure what to expect, as it turns out the heat treatment process for hammer tools is very similar to rock drills-carburizing in pit furnaces using an endothermic atmosphere with oil quenching-in the case of “Caldervale” the company has two reasonably large pit furnaces.
 
The pit furnaces form only a small part of the firm’s heat-treating capacity as “Caldervale” also operates as a commercial heat treater-the largest in Scotland as it turns out. To compliment the pit carburizing furnaces we found two induction systems (one a very long vertical scanning system, the other a dual spindle scanner) and several stress relieving, annealing and normalizing furnaces.
 
The centerpiece of the entire department is a substantial “salt” system offering the “QPQ” process-for those not familiar with this process we have this brief summary;
 

Nigel Troth, Sales Manager, SSi Europe, Jim Hamilton, Technical Sales Manager Caldervale Group

“QPQ” is a thermochemical surface treatment process that uses “quench, polish, quench” to significantly improve a metal’s wear resistance, corrosion resistance, and fatigue strength. It involves three main steps: an initial quench (nitrocarburizing) to form a hard compound layer, followed by a polish to improve the surface finish, and a final quench (oxidation) to create a corrosion-resistant oxide layer. This process results in a durable, black surface that can replace other treatments like chrome plating and minimizes distortion in the treated parts.”
 
Joining us in our tour was Mr. Nigel Troth, Sales manager for furnace controls company “SSi Europe”.
 
We thank Jim Hamilton for his time and his openness about the company.
“QPQ-Tuffride”; Gord Montgomery, “The Monty Heat Treat News”, Jim Hamilton, Technical Sales Manager, Caldervale Group