Jun 16, 2020 Aggregates blog

The story of C Series jaw crushers – where it all began?

Harri Lehtonen
Harri Lehtonen
For 45 years, Nordberg® C Series™ jaw crushers have proven their reliability in different primary crushing operations in aggregates, mining and recycling applications, with up to 11 000 jaw crusher installations. Their pinned and bolted, non-welded frame and two wedge setting adjustment system is still in use, helping our customers to meet their production targets in their crushing operations. But where it all began? And where the C in the series’ name is derived from? Let’s give the floor to the father of C Series, Harri Lehtonen, who will tell us the story behind the C series jaw crushers.
C Series jaw crushers

The beginning of C Series jaw crushers

It all began in 1970’s. My manager at the time asked if I would want to start developing jaw crushers in his team. It was yes from me. When I started to develop jaw crushers, I started to notice many things that bothered me in the jaw crushers of that time. At that time, jaw crushers in production had different type of features; welded frame, fully casted frame, bolted frame with casted side plates and with rolled side plates, all because they were from different eras. I realized that improving individual parts and crushers was not enough – the crushers had to be thought as a whole to optimize design and supply chain. That was the starting point of the new kind of series of jaw crushers; the C Series.

I realized that improving individual parts and crushers was not enough – the crushers had to be thought as a whole.

I spent a lot of time studying the jaw crusher’s design in full detail. I got also full support from my manager who helped me to gather theoretical information regarding crusher theory and how to design a machine series. I spent two months studying capacity estimation calculations, cavity operation, power consumption and crusher kinematics. Finally, I came up with the pinned and bolted design which gave the jaw crusher series simple, scalable, and extremely robust frame construction.

I spent two months studying capacity estimation calculations, cavity operation, power consumption and crusher kinematics.

The development of the jaw crushers continued, and the first prototypes were introduced to the market. The new series of jaw crushers decided to be named as the C Series. The letter C was derived, evidently, from the word “crusher”.

Harri Lehtonen in 1975.
Harri Lehtonen in 1975.

Market reaction was positive

When the C Series was launched, the market reaction was positive, especially with the development of Lokotrack’s the C Series really hit the ground running. This was partly because early C Series jaw crushers were 30% lighter than the other crushers on the market, but just as tough and reliable. Sure, like any other new product in this tough industry, the crusher went through some fine-tuning based on customer feedback.

The main design principle of the C Series kinematics-wise was to improve efficiency which was done by speeding up the work cycle, and this was noted by the customers and sales people alike by the changed sound and rhythm of the crushers; the crushers had higher RPM than anything else before them. High reduction and high capacity were characteristics of the C Series jaw crushers even back in those days.

 

C Series jaw crushers in 2000s
Today's Nordberg C Series jaw crusher looks a bit different than back in the days but the original pinned and bolted design principle from the 1970's is still in use.

The original design of C Series jaw crusher is still in use

Over the years, the C Series jaw crushers have received multiple improvements and optimization. For example; developments in the 3D design capabilities have enabled FEM (Finite Element Method) calculations, as well as digitalized signal processing and mathematics has made crushing simulations possible. Understanding the soul of the jaw crushers have further developed the crusher design and its operation. However, still to this day, the original pinned and bolted design principle from the 1970’s is in use, giving the Nordberg C Series jaw crushers their excellent fatigue life, flexibility and strength. Today, 11,000 jaw crushers have been delivered globally proving their reliability and durability in primary crushing in stationary, mobile and portable plants in aggregates, mining and recycling applications.

 

About Harri Lehtonen

Harri Lehtonen started his journey at Metso in 1965 in railway department that was still in operation at the time. He worked in the engineering of railway crane construction. After the railway department was closed, he changed to engineering department. He worked among different projects before he was asked if he wanted to start to develop jaw crushers. And that was the beginning of the C Series jaw crushers, a journey that is still on-going as strongly as ever!

Video on the development of C Series™

Dive into the history of Metso Nordberg® C Series™ jaw crushers and find out how the series has continued its success story through decades. In this video, Harri Lehtonen, the developer of the Nordberg® C Series™ jaw crushers gives insight into the early days and later developments of these trusted jaw crushers.

Nordberg® C Series™ jaw crushers
Up to 11,000 installations since 1975
We are now Metso Outotec
Read more about the company at mogroup.com.