Providing ‘maintenance free’ solutions
21 April 2016
Here Dr-Ing Hans-Albert Städler, customer engineering director Europe at Alcoa Fastening Systems & Rings, looks at what the term ‘maintenance free’ truly means and the importance of providing ‘maintenance free’ solutions.
For Alcoa Fastening Systems & Rings (AFSR) what does the term ‘maintenance free’ mean?
Defining ‘maintenance free’ varies depending on which industrial sector AFSR is supplying its products. However, as the term relates to the actual mechanical performance of fasteners, the best example is the use of Huck® BobTail® lockbolts in civil engineering.
BobTail is internationally recognised as ‘maintenance free’ by Deutsches Institut für Bautechnik (DIBt). DIBt approval is generally sought for non-regular products for which international standards have not yet been set.
The rigorous test programme prior to approval considers a number of factors including:
- Static performance (shear and tensile strength) in accordance with EN 1993-1-8.
- Clamp preload ability also in accordance with EN 1993-1-8.
- Fatigue testing notch group evaluation in accordance with EN 1993-1-9. BobTail is registered in a high notch group in terms of tension fatigue, for example, CD 63 for one inch and CD 67 for 20mm fasteners respectively, which is three to four times better than conventional high resistance bolts.
- Corrosion testing in line with ISO 9227 and classification as per ISO 12944 classes C4 and C5, which is also termed as red rust resistant.
Each of these sub-sector approvals resulted in DIBt recognising and accrediting the BobTail as a high performance fastener that is ‘maintenance free’ in terms of preload.
What are the benefits to engineers of using a ‘maintenance free’ solution?
In essence engineers will have no need to plan, prepare and execute additional and costly follow up maintenance activities. Nuts and bolts have the potential to loosen in both static and dynamic civil engineering applications. This means they are not ‘maintenance free’ as subsequent visits to the installation to retighten them and maintain the preload are often required.”
How does AFSR ensure that the products its supplies are ‘maintenance free’?
AFSR has rigorous and robust internal production control procedures, which cover all of the steps from the raw material arriving at its facilities to final products being shipped out to customers. These procedures cover all the methods of production carried out within boundaries of pre-set environmental guidelines, operator training, and suppliers and sub-contractors adhering to AFSR’s product specifications.
Any changes in the above; in the design of the product; or relocation of equipment at the production facilities; are monitored by accredited DIBt inspectors.
Why should engineers use AFSR’s products?
There are numerous reasons why engineers should use AFSR’s products, such as the ease by which lockbolt and blind rivet potential fastening solutions can be calculated and dimensioned, as well as the consistent quality of products.
In addition, engineers will receive technical advice and support from highly qualified and knowledgeable staff in terms of fastener recommendation for the potential application and after sales support. AFSR also offers a complete range of complementary and often bespoke tooling, designed and manufactured in-house.
Once an appropriate product has been identified as the very best fastening solution for the application, other advantages include speed, ease and safety of installation - in some cases saving up to 70 percent operator time compared to previous methods such as welding.