TAPTITE® working to reduce vehicle weight 05 April 2022

Many manufacturers can experience assembly problems with high hardness materials including being too hard and thin to use a thread forming screw and therefore a weld nut cannot be effectively attached. REMINC has worked together with nut suppliers to make self-piercing clinch nuts compatible for use with TAPTITE 2000® and TAPTITE PRO® CORFLEX®-I thread rolling fasteners.

The automotive industry has utilised several technologies and materials to reduce vehicle weight in both conventional internal combustion engine and electric powered vehicles. The use of aluminium and magnesium has provided lightweight solutions in some applications. However, there are several areas where the use of steel sheets is still preferred due to the increased mass and size required for aluminium and magnesium components to attain the equivalent strength of steel. 

Therefore, automotive assemblers often prefer to use self-piercing clinch nuts, particularly when a structural joint is required. Advancements in sheet steel composition have produced high strength low alloy (HSLA) and ultra high strength low alloy (UHSLA) sheet steels. These grades are being used more extensively today as they help vehicle assemblers achieve their weight reduction goals. The higher strength steel grades not only allow for thinner sections to be used but also reduce weight while not increasing mass.

Research Engineering & Manufacturing Inc (REMINC) and its sister company, CONTI Fasteners AG, have therefore worked with some nut suppliers to make the self-piercing clinch nuts compatible for use with TAPTITE 2000® and TAPTITE PRO® CORFLEX®-I thread rolling fasteners. The nut's plain bore hole size and length of engagement are optimised so that grade strength Class 10 bolts can be driven into these nuts creating a joint which meets Class 10 strength levels.

REMINC comments: “The combination of TAPTITE thread rolling screws and clinch nuts has been popular in the assembly of automotive vehicle seats. Seat assembly is an application where weight savings must be achieved without increasing mass so the seat design remains compact.”

These fasteners are also typically used in chassis and body in white applications, with body in white applications typically requiring several fastening sites that usually become coated with eCoat and primer. Pre threaded nuts, when filled with eCoat, create the possibility of the joint having eCoat remaining between the machine screw and the internal thread. REMINC suggests this can be avoided by driving a TAPTITE screw into a plain bore hole where the screw will push the eCoat out through the end of the nut during thread forming.

Claire Aldridge Editor t: +44 (0) 1727 743 889

Having spent a decade in the fastener industry experiencing every facet – from steel mills, fastener manufacturers, wholesalers, distributors, as well as machinery builders and plating + coating companies, Claire has developed an in-depth knowledge of all things fasteners.

Alongside visiting numerous companies, exhibitions and conferences around the world, Claire has also interviewed high profile figures – focusing on key topics impacting the sector and making sure readers stay up to date with the latest developments within the industry.