Product category:
Fasteners, threaded and non-threaded
News Release from: Arnold Umformtechnik | Subject: Remform screws
Edited by the Engineeringtalk Editorial
Team on 09 June 2004
Plastic screws answer industry's demands
With the increasing use of plastics for both technical and commercial reasons, there is an increasing need for a reliable and cost-effective fastening method that can be used safely in all processes.
With the increasing use of plastics for both technical and commercial reasons, there is an increasing need for a reliable and cost-effective fastening method that can be used safely in all processes According to Thomas Jakob, Product Manager at Arnold Umformtechnik, the most economical way to satisfy these rather demanding requirements and a genuine alternative is the use of Remform screws for direct plastic screw joints
This article was originally published on Engineeringtalk on 20 Feb 2004 at 8.00am (UK)
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Arnold Taptite 2000 are thread forming screws which form a female thread when screwed into a preformed hole.
Reliable alternative to normal welding screws
Arnold Strux screws are captive fasteners which are pressed into formed sheet metal parts providing a sheet metal component ready for installation.
This type of screwed connection will ensure the lowest possible assembly costs and similarly low costs for the actual fastening elements as well.
This is also confirmed by VW standard 01128, which contains recommendations for the application of plastic connections.
Due to the threaded flank's asymmetric shape, the Remform screw ensures the high operating safety of the entire connection, so that reworking jobs as a result of assembly faults or even a total failure of the product in the market (often combined with an image loss) can be avoided.
Further reading
Clinch bolt offers the best of both worlds
The old saying "time is money" has prompted the engineers at Arnold Umformtechnik to develop a fastening element which has never been seen before.
Cost-effective reliable direct screwing of plastic
The asymmetric thread profile of the Arnold Remform screw optimises the material flow of the formed plastic thread.
The asymmetric geometry of the thread will not only optimise the material flow of the shaped plastic thread, it will also increase the drawing forces as compared with those of conventional symmetrically threaded flanks.
"The benefit for the designer is patently obvious", says Jakob.
"The high safety of the assembly process can be explained with the big difference between the screwing-in momentum and the over-twisting momentum as well as with a high stress absorbing capacity which is the result of an enlarged cross-section of the thread core".
Further benefits are the favourable assembly costs because of the few components involved, the easy recycling and the optimised component design as regards the installation room and the weight, which leads to short cycle times during the injection-moulding process.
Arnold Umformtechnik has recently demonstrated that this is not only a theory, when the company introduced the use of the Remform screw in the production facilities of a renowned manufacturer of washing machines.
"The customer required that the two parts of the suds drum for a washing machine were to be joined and that the following parameters were to be met".
"In order to ensure the drum's tightness, the residual locking force had to be sufficient beyond the washing machine's useful life".
"The customer also required temperature resistance of -10 to +65C, extremely short assembly times (less than 1s per screw) and good vibration resistance".
"By using the Remform screw we have been able to satisfy this requirement profile in the most optimal way", says Jakob.
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