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Special jaws crush 100% more than ordinary manganese at Råsjö Kross

In an industry where production time is the most critical factor, equipment has to function according to plan. Service stoppages have to be minimized and planned in advance. This is especially important when the equipment is moved around on the basis of need.

Råsjö Kross, which has been operating since 1964, is a well-established company within construction crushing. The company produces and sells natural gravel and crushed rock from gravel and rock quarries in different parts of Sweden. The company has several track-mounted crushers, which are transported by trailer to the locations where they are needed.

“Ensuring production is important to us. We crush rock, and the crusher has to be in constant operation. Time is money, which means that all downtime has to be minimized and avoided,” says Fredrik Råbom, Production Manager at Råsjö Kross.

Fredrik Råbom, Production Manager at Råsjö Kross

Quality = stability

Råsjö Kross has tested wear parts from different suppliers over the years. The company has been tempted by low-price products at times, but Fredrik says quality pays off.

“Sometimes the purchase price has made it impossible not to try a product, but I have been disappointed one too many times. Now I want products we can trust — good quality with the right fit that last a long time,” explains Fredrik.

Metso and Råsjö Kross have been cooperating for many years, and they currently have an agreement in place for wear parts. Metso supplies the parts at specified times, giving both parties predictability and reliability.

Twice the wear life promised

In 2014, Råsjö Kross was given the opportunity to try out Metso’s new, patented solution MX jaw in its Nordberg® C125 crusher. The MX jaw has a higher purchase price than Metso’s standard manganese jaws, but since Metso could promise twice the wear life or corresponding compensation, the choice was easy.

MX jaws are unique because the jaws are reinforced with durable material in areas where the jaws are exposed to extra wear. The reinforcement results in long wear life and thus offers better reliability for a machine that is meant to crush 400 metric tons per hour.

“It was quickly obvious that the wear on the MX jaws was less than on the jaws we had used previously. Also, the profile of the jaw remains unchanged throughout its lifetime, which means we can wear them out to the maximum extent. In addition to the reliability offered by a jaw that just keeps on crushing without running into any issues, the long wear life means we can save one day of service work per jaw. In other words, we get to skip one replacement round, which means our servicemen can be sent to other assignments,” says Fredrik.

The MX jaw lasts about twice as long as Metso’s standard jaw, which Råsjö Kross used previously — 450,000 metric tons compared with 220,000 metric tons. The increased wear life means that the fixed and the moving jaws in the C125 last about the same amount of time. Consequently, Råsjö Kross's service personnel who travel around to the various quarries to perform maintenance can avoid a trip, and fewer replacements automatically means greater safety. 

“The less often we change parts, the fewer risks we are exposed to. The jaws from Metso also have a great fit and do not expand, which simplifies replacement,” says Fredrik.

Fredrik Råbom and Micael Larsson (Metso) are looking at the new jaws that have been delivered.

Positive cooperation

The MX jaw used in the C125 crusher has been in place since March 2017. The machine has worked in quarries in Åkersberga, Bergsjö, Åre and Gillinge during this period. The type of rock varies, but this has not affected the MX jaw’s capacity.

“I have to admit that the MX jaw exceeded my expectations during this period. I brought a new jaw up to Åre because I thought it would be time to do a replacement soon. Now we are back in Gillinge, and the jaw is still showing excellent performance even though it has already crushed 430,000 metric tons,” says Fredrik.

The positive results have convinced Råsjö Kross to utilize MX jaws also in its crushers manufactured by suppliers other than Metso.
“For me it is important to cooperate with a supplier who offers good quality and keeps their promises. Since I am satisfied with the MX jaw’s performance, I naturally want to achieve the same results and wear life for all of the jaw crushers. With Metso, this is possible — thanks to great dialogue and cooperation,” concludes Fredrik.

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