2026 Stabilizing mining machinery with Nord-Lock® Steel Washers
Spence, a major mine in the LATAM region, relied on Nord-Lock products to solve bolt loosening from intense vibration.
Large-scale mining often features extreme conditions, and operators frequently need to implement solutions for things like eliminating excessive vibration. This ensures more reliable performance and improves safety, but can also attest to the soundness of those solutions beyond the mining sector.
At the Spence mining operation in northern Chile, high levels of vibration reached a point that affected the efficiency of critical machine assets. From unscheduled downtime and repeated maintenance to personnel safety risks and potential equipment damage, the issue of vibration-induced bolt loosening posed potentially serious problems.
Located in the Atacama Desert of Chile’s Antofagasta Region, Spence is an open-pit copper mine that’s part of the BHP subsidiary Pampa Norte. It’s one of the country’s most productive mines, with an annual output of just over a quarter of a billion tons of copper.
According to Andreina Pérez, Sales Engineer for Nord-Lock covering the Latin America region from the Nord-Lock Group’s office in Santiago, the bolting solution provider typically connects to such mining operations through third-party distributors. A key part of Pérez’s role is sharing with distributors everything they need to recognize issues that Nord-Lock’s wedge-locking technology can address and properly utilize it to do so.
“I basically support distributors with training, capacity building, and field visits. If there’s an application to be developed, I provide technical support,” she explains.
And it was through one such distributor, who was a direct supplier to the mine, that Nord-Lock® Steel Washers were installed at Spence.
An industry environment prone to extreme vibrations
Like most modern mines, Spence processes minerals on-site. A major part of its concentrator operations is the use of grinding mills. These mechanical rotating drums break up and crush ore for refinement. Spence uses a large semi-autogenous grinding (SAG) mill for primary grinding of large ore pieces into rocks and pebbles and two smaller ball mills for secondary fine grinding and regrinding stages.
While gear drive configurations connect to the ball mills to rotate their drums, a massive gearless mill drive (GMD) system powers the SAG mill – directly mounted on the mill’s shell to deliver extremely high torque with mechanical simplicity. The GMD’s extreme vibrations, however, were repeatedly loosening the bolts on its rotor cover. It soon became clear that securing those connections was necessary for the sake of operational efficiency and worker safety.
“Providing an effective solution would avoid downtime costs for maintenance but also potential damage to the equipment, because this part of the application is a critical point to take care of,” explains Pérez, who also notes the increasing risk of accidents and injuries without a proven anti-loosening solution.
Significantly improved safety and efficiency
Based on the distributor’s recommendation, Spence began replacing the GMD’s conventional washers with Nord-Lock® NL 64 Steel Washers in October 2024. Through their wedge-locking design, the washers are able to maintain clamp force and secure fastening to keep bolted joints from loosening once tightened. Being made from steel also gives them additional durability and prevents corrosion.
Spence installed Nord-Lock washers on the GMD’s rotor cover. But they were also installed on the GMD’s stator – which generates the magnetic field that drives the rotor – strengthening the machine’s joint integrity to protect the motor from impact and wear. Both instances were relatively quick and straightforward, handled by the operation’s maintenance crew with no reported issues.
A spokesperson for Spence says the mine operator has been very satisfied with the implementation of Nord-Lock® NL 64 Steel Washers, stating: “Since installation, we have had no issues with bolt loosening, which has significantly improved equipment operation and safety. We would recommend this product to any mining operation seeking reliability and efficiency.”
“It’s a product that will also work in other industries where most requirements are less demanding”
For Pérez, Nord-Lock’s success at helping a large-scale mining operation like Spence overcome a major challenge involving critical machinery in such extreme conditions is invaluable evidence of the washer’s capabilities.
“The fact that the washer was a solution proves its effectiveness and reliability,” she explains. “It’s like a demonstration that the product really works, and not in an educational way where you bring samples to show it in action. It’s people in the field using the washer, and it’s effective.”
What’s more, she argues, the fact that it’s a solution in such intense conditions supports the case for its implementation in almost any other environment.
“It’s important that the Nord-Lock washer works in the mining sector because the vibrations and conditions are so demanding,” says Pérez. “But there’s no single application, and there’s no sole industry for it. It’s a product that will also work in other industries where most requirements are less demanding.”