Super Flush Torque Controlled Screw

Abstract

<div class="section abstract"><div class="htmlview paragraph">Aerodynamic and cosmetic requirements are more and more stringent on new aircraft programs. External aircraft surfaces should ideally be free of any discontinuities and fasteners are usually local points of concern. While pins or lockbolts generally exhibit flush and smooth head surfaces, screws have inherent driving recesses which remain visible after finish paint application. Such screws are typically used in combination with anchor nuts to attach the panels closing thin wing boxes. The AeroDrive™ screw is a global solution to avoid recesses while improving mechanical characteristics of such structural joints. The AeroDrive™ screw features an additional drive head designed to break at a defined torque during installation, leaving a flush and smooth head surface. This paper describes the various benefits brought by this solution beyond the surface finish improvement such as: accurate torque control (±5%), improved head resistance (no recess weak point), no torque limitation due to recess resistance, no cam-out nor push-out issue during installation, and automation options.</div></div>