Browse Topic: Screws

Items (514)
This standard provides a test method for determining the torque-tension relationship of a fastener finish as applied to a surrogate screw for the purpose of measuring the frictional characteristic of the fastener finish. The results obtained by this test shall be used as a process control attribute of the fastener finish and shall not be utilized for specific applications.
USCAR
This document covers bolts and screws made from a corrosion and heat resistant, precipitation hardenable, iron base alloy of the type identified under the Unified Numbering System as UNS S66286.
E-25 General Standards for Aerospace and Propulsion Systems
This Aerospace Standard establishes the preferred diameter-pitch combinations of ISO metric 60° screw threads recommended for use in the aerospace industry for metric module bolts and nuts.
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
Mechanical Strength and Failure Mode of Flow Drill Screw Joints in Coach-Peel Specimens of Aluminum 6082-T6 Sheets of Different Thicknesses and Processing Conditions2018-01-01164/3/2018
The mechanical strength and failure mode of flow drill screw (FDS) joints in coach-peel specimens of aluminum 6082-T6 sheets of three different thicknesses of 2.5, 2.8 and 3.0 mm and three different processing conditions under quasi-static loading conditions are investigated by experiments. The experimental results indicate that the mechanical strength and failure mode of FDS joints in coach-peel specimens are affected by the specimen thickness, clearance hole and stripping. The maximum load of a coach-peel specimen with an FDS joint with clearance hole increases as the thickness increases. For each of the thickness groups of 2.5, 2.8 and 3.0 mm, the maximum load of a coach-peel specimen with an FDS joint without clearance hole is lower than that with clearance hole. For the thickness group of 2.8 mm, the maximum load of a coach-peel specimen with a stripped FDS joint with clearance hole is lower than those of non-stripped ones with and without clearance hole. The FDS joints in coach-peel specimens of different thicknesses with and without clearance hole and stripping can have the screw head penetration, the lower sheet pull out and the screw pop out failure modes, depending on the specimen thickness, clearance hole and stripping.
Huang, Chien-PoChen, Wei-NingSung, Shin-JangPan, Jwo
This SAE Aerospace Standard (AS) defines an external thread with a rounded root radius based on a minimum root radius of .108 × Pitch.
E-25 General Standards for Aerospace and Propulsion Systems
Avoiding Safety Scandals by Controlling the Risk of Material Changes2017-01-03733/28/2017
Achieving functional safety in mechatronic systems with growing product functionality is a major challenge in systems engineering. Following the current discussion, this challenge is mostly allocated to electronics and software development. For most of the scenarios this focus is feasible. Product design - the construction of the product - defines the properties and the appearance of the product by shape, material and assembly. So, the product design is often not under control of the safety management system. A hazardous deviation of part shape can be easily identified after the parts product or at least at its mounting. A wrong assembly is controlled by assembly documentation or data (e.g. screw torques) and identified at end of assembly line checks. The identification of a hazardous material choice depends on the product material class. Product materials can be separated into two classes: passive or active materials. Passive materials (e.g. car body) can be distinguished in as passive materials with constant shape (stiff) and variable shape (flexible) (e.g. damper, spring). The liability of those materials regarding their usage in the product is tested in labs in prototypes in prior. Active materials (e.g. fluids, gases), or functional materials fulfill, trigger or directly influence the functionality of the product. The choice of a functional material is not always made by the electronics engineering. Therefore, it is not under control of safety management processes. Never the less functional material, especially with radical behavior, underlie other safety regulation. Explosives for example, can be integrated in a product or system and are restricted by specific standards. This technology report reflects the verification methods of functional materials today. The responsibility of the product design engineer is discussed as well as the relevant standards. The challenge of achieving complete product compliance with functional materials is shown by the technology analysis of the Takata airbag recall. The required and available methods to control risks of functional materials choice and change are listed and rated. Gaps in existing engineering processes and regulations are identified. A strategy to close those gaps is explained.
Koark, Fabian Jorg UweBeul, Christian
SAE J485 specifies the recommended nominal diameters and locations of holes in bolt or screw shanks, and nominal widths and depths of slots in nuts, for use with the recommended sizes of inch-series cotter pins, as shown in Table 1.
Fasteners Committee
High Flushness Installation of Countersunk Fasteners2016-01-21099/27/2016
Aerospace structures are typically joined to form larger assemblies using screw lock or swage lock fasteners or rivets. Countersunk fasteners are used widely in the aerospace industry on flying surfaces to reduce excrescence drag and increase aircraft performance. These fasteners are typically installed to a nominal countersink value which leaves them flush to the surface before being locked into position. The Northern Ireland Technology Centre (NITC) at Queen’s University Belfast has developed and demonstrated two processes which enable high tolerance flush fastening of countersunk fasteners: The ‘Flush Install’ process produces countersunk holes based on the specific geometry of each individual fastener; The ‘Fettle Flush’ process accurately machines fasteners to match the surrounding surface. Flushness values well within the allowable tolerances have been demonstrated for both Flush Install and Fettle Flush processes. The Flush Install process uses a physics based, experimentally verified constant ‘ζ’ based on the material types and thickness of the stack being assembled. The Fettle Flush process uses a proprietary toolpath to ensure low machining forces, optimum flushness and excellent surface finish. Both processes were developed by the NITC to TRL4 before transferal to the Manufacturing Technology Centre (MTC) in Coventry for use within a TRL5 application, a Ground Based Demonstrator (GBD) wing at the MTC which further demonstrated the two processes.
Morgan, MichaelMcClory, CarolineHiggins, ColmJin, YanMurphy, Adrian
Items per page:
1 – 50 of 514