Thread locking ensures plant safety in aggressive environments

Failure of a threaded assembly through self-loosening not only risks lost production but also worker safety, a situation an Australian mining operation faced when M36 anchor bolts threatened the collapse of the jaw crusher equipment frame.

The bolts had been locked by spring washers which simply could not rise to the challenge of securing bolts on a piece of equipment subjected to continuous vibration and high shear forces. This resulted in the loosening – and ultimately the breaking off – of anchor bolts and the collapse of concrete footings.

Spring washers – also known as lock or helical spring washers – are one of the most popular mechanical devices for securing threaded fasteners against self-loosening. The washer is squashed flat when the nut is tightened against the mounting surface so that its sharp edges dig in to prevent the threaded fastener unwinding.

In practice, a spring washer may delay the length of time it takes for the bolt to loosen, but it will not permanently prevent it. The main reason is that the split washer does not solve the gapping issue, the free space remaining between the threads of the nut and the bolt.

On a typical threaded assembly there is just 15% efficient metal to metal contact between the threads. Everything else is empty space that enables plenty of side to side movement for the bolt. Additionally, being metal itself, a spring washer can cause damage to contact faces and corrode in place.

For the Australian mining operation, this problem was exacerbated by the size of the bolts. The bigger the bolts, the bigger the gap between threads which leads to more vibrational impact on the assembly. This realisation resulted in the company changing to adhesive thread locking with Henkel’s LOCTITE 270.

This is a high strength formulation that completely fills all gaps between the thread and prevents any movement of the bolt within the nut. Secured this way, the assembly is completely vibration-proof but can still be easily dismantled with hand tools for repair and maintenance. Additionally, the liquid thread locker seals the threads against humidity and dust, preventing corrosion and surface erosion.

This simple adjustment to working practice has not only underpinned productivity but contributed to a safer working environment. It is economical too as one 50ml bottle of liquid thread locker is sufficient to secure around 850 M10 bolts but, unlike spring washers, can be used on any bolt size.

Henkel Ltd

Wood Lane End
Hemel Hempstead
HP2 4RQ
UNITED KINGDOM

+44 (0)1442 278000

technicalservice.loctite@uk.henkel.com

www.henkel.com

More news
Farnell, NXP and Doulos present new Industry 4.0 webinar
Farnell has announced the launch a new global webinar covering ‘Automation and Edge AI for Industry 4.0’ in partnership with the Element14 Community, NXP and Doulos on Wednesday 24 August.
Needle valves receive ISO 15848-1 Class C low emissions certification
Parker Hannifin is unveiling a series of valves tested to ISO 15848-1 Class C, a standard that sets out the measurement, test and qualification procedures for fugitive emissions from industrial valves.
Thorite offers same-day hydraulic hose assembly service
Air and fluid power specialist Thorite has launched a same-day hydraulic hose assembly service to help customers reduce downtime and control costs.
Festo demonstrates bioreactor for large-scale photosynthesis of algae
Festo presented the PhotoBionicCell research project at the Hannover Fair – a bioreactor that enables the efficient and large-scale photosynthesis of algae.
Actuator increases accuracy and productivity of bagging machine
When end users of a precision bagging machine started using economical bags with inconsistent sizes, this impacted accuracy and productivity of the bulk bagging process.
World’s first e-chain made of 100% recycled material
Conserving resources and extending the product life cycle are the objectives of the new Igus cradle-chain E2.1.CG, which the company says saves 28% CO2 versus current e-chain production.
Siemens Congleton factory accelerates towards net zero goal
Siemens’ Congleton factory is on track to achieve carbon neutrality this year – eight years ahead of its original target.
Full speed ahead for a custom conversion
A vision for a customised camper van led Leigh McCarron to Minitec UK. Working together to Leigh realise his dream, Minitec advised on the choice of profile that would turn an old transporter vehicle into a customised ‘king of the road’ camper van.
Inductive sensors prove a ‘jack of all trades’ in bridge construction
When a specialist assembler of prefabricated bridges needed a rugged sensor for position sensing on its hydraulic cylinders, it turned to Contrinex.
Digital tools to support engineering design
Nowadays in engineering, digital tools are an essential part of a design engineer’s daily life and any tools that are available freely are naturally an added bonus.

Login / Sign up