Browse Topic: Nuts

Items (980)
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Why preload retention matters more than fastener grade. In exhaust and thermal management applications, joint failures are frequently attributed to fastener fracture or rotation-driven loosening. In practice, many joints in these systems fail through a different mechanism entirely: gradual preload loss that occurs without fracture, without visible nut rotation, and without any indication during installation or room-temperature inspection that the joint is degrading. Understanding this distinction is becoming more important as exhaust system temperatures increase, assemblies get lighter, and vibration environments remain demanding. The gap between what a room-temperature validation protocol confirms and what a joint actually experiences in service has widened considerably in recent years, and conventional fastener selection methods have not kept pace.
Kapa, Kyle
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This SAE Aerospace Recommended Practice (ARP) defines the minimum across hexagon corner dimensions for fluid tube fittings and nuts. The ARP covers commonly specified inch and millimeter hexagon sizes.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Automotive seat system is one of the most complex systems in vehicle for its technical and functional requirements. Seat is designed to meet all regulatory requirements subjecting it to multiple tests with loading patterns which caters to the occupant safety. Varied loading and load path for different test requirements cause seat bolts to experience tensile, compressive, bending moments and shear loading. Shearing along bolt length is one of the common failure modes observed during design validation by physical tests. In the world of CAE, there is an industry approach to find the bolt failures at nut and head for all kind of loads. But shear failures along varied bolt lengths are not accurately predictable as multiple sheet metal parts will transfer loads unevenly onto bolt length and it becomes challenge to find which component is leading to shear failure. Hence by adding multiple rupture layers across the bolt length shear and its location could be predicted. Further, to resolve the bolt shear issues, engineers generally try to modify the component design for better energy absorption, but our research found that, only by increasing the clearance around bolt hole will resolve the bolt shear issues. During one of such failures, a new approach of adding multiple rupture layers along bolt length was used which predicted the shear failure modes and location of shear as observed in physical tests. The CAE bolt model thus updated with new procedure for all such future bolt shear failure prediction in seat structure models.
RJ, Jethendra, Chiu, Li-Ban
E-25 General Standards for Aerospace and Propulsion Systems
The purpose of this Standard is to provide installation dimensions for shaft nuts and their companion keywasher. The Standard type typically shown on MS9951 and MS9952, but is also suitable for parts which are dimensionally equivalent.
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
E-25 General Standards for Aerospace and Propulsion Systems
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
The purpose of this test is to evaluate the axial strength of the nut seat of wheels intended for use on passenger cars, light trucks, and multipurpose vehicles. In addition, a minimum contact area is recommended to ensure enough strength for the rotational force in tightening a nut against the nut seat. While this test ensures the minimum strength of the nut seat, the wheel must also have a degree of flexibility. This flexibility, as well as bolt tension, are important to maintain wheel retention.
Wheel Standards Committee
E-25 General Standards for Aerospace and Propulsion Systems
This procurement specification covers all metal, self-locking wrenching nuts, plate nuts, shank nuts, and gang channel nuts made of a corrosion and heat resistant nickel-base alloy of the type identified under the Unified Numbering System as UNS N07001.
E-25 General Standards for Aerospace and Propulsion Systems
In modern automotive manufacturing, ensuring the integrity of suspension joints under real-world driving conditions is a critical aspect of vehicle safety and performance. These joints endure substantial transverse loads and large vibrations due to irregular road surfaces, dynamic maneuvers, and varying environmental factors. As a result, bolt loosening becomes a significant concern, compromising joint integrity and overall vehicle reliability. This paper delves into the challenges associated with maintaining joint integrity, specifically focusing on pre-load determination, torque application, and production-related issues. The pre-load generated during torquing is the primary factor that ensures a suspension joint remains securely fastened under dynamic road conditions. This pre-load is derived using road load data acquisition (RLDA) inputs, which capture the forces acting on the joint during actual driving scenarios. RLDA inputs provide critical insights into the forces experienced by a joint, enabling engineers to calculate the optimal pre-load required to withstand real-world stressors. The torque applied during assembly is directly dependent on these calculated pre-load values, ensuring the joint remains secure during the vehicle's lifecycle. During production ramp-up, several concerns arise that impact the torque application process. Friction at the bolt and nut interface plays a significant role in achieving the desired pre-load. Variations in friction surfaces, such as presence of lubrication, debris, or surface roughness, can lead to major issues. These torque-related concerns have cascading effects on production efficiency and workplace safety. Additionally, the increased strain on assembly tools due to high torque demands reduces tool life and increases maintenance costs. Automotive suspension joints are subjected to significant challenges during production ramp-up due to the interplay of friction, torque, and pre-load parameters. Addressing these concerns is essential to ensure joint integrity, improve production efficiency, and create a safe workplace environment. By adopting advanced monitoring systems, enhancing friction control, and optimizing tool design, manufacturers can mitigate the risks associated with bolt loosening, breakage, and high torque issues, securing the reliability and safety of suspension joints in real-world driving conditions.
Kumar, Sabeesh, Vasant Kumar, Jesse Daniel, Mishra, Harshit, Senthil Raja, T, Nayak, Bhargav, M, Sudhan, Namani, Prasad, Vibhute, Shekhar
The hydraulic steering gear, in the ball & nut configuration, was introduced in series in 1985, commonly encompassing single circuits with only one hydraulic steering. In medium-sized commercial vehicles, the torque (force) required to turn the wheels through direct mechanical connection is approximately 400 Nm when the vehicle is stationary. By using hydraulic steering, the required torque is reduced to about 50 Nm. When the load of the front axle exceeds 6.7 tons, a dual steering gear system can be used, delivering 200% of the total force. Additionally, the dual steering gear system provides a better turning radius, eliminating the need for a steering assist cylinder, thus giving more space for the front wheels to turn. This article will describe the development of a dual gear for a dual steering gear for commercial vehicles. Schematic diagrams of a dual steering gear and how the system can deliver the required output torque for the steering process it will be shown. The system is designed to provide auxiliary output torque to the steering system without changing the gear ratio neither reducing the sensitivity of the steering wheel to the driver. The dual gear steering type should provide the system with greater torque assistance than the main steering due to better use of the pressurized area. In addition, the dual gear has 303 less components compared to the main gear leading to reduced manufacturing costs, as existing concepts from the ball-nut steering components can be utilized in the construction of the dual gear system. The results presented in this article indicate that during the dry-parking maneuver, 80% of the nominal pressure was achieved, yielding an output torque of 11700Nm at 170bar. In the figure-eight maneuver, 50% of the nominal pressure was attained. The system is deemed effective in delivering sufficient output torque to the steering system without compromising the sensitivity of the steering wheel to the driver or the number of steering wheel rotations.
Masunaga, Natália Sayuri, Santos, Antídio, Silva, Everton, Pedroso, Hugo, Destro, Daniel, Moura, Márcio
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This SAE Aerospace Recommended Practice (ARP) provides the recommended procedure for obtaining desired preloads in aircraft wheel tie bolts when mounting tires and assembling the wheel. It is generally referred to as the snug-angle bolted joint assembly procedure. It is also known as the “torque-turn” procedure in the heavy equipment ground vehicle industry.
A-5A Wheels, Brakes and Skid Controls Committee
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This specification establishes the requirements for the following types of self-locking nuts in thread diameter sizes 0.1380 through 0.6250 inch: a Wrenching Nuts: i.e., hexagon, double hexagon, and spline nuts. b Anchor Nuts: i.e., plate nuts, gang channel nuts, and shank nuts. The wrenching nuts, shank nuts, and nut elements of plate and gang channel nuts are made of a corrosion- and heat-resistant nickel-base alloy of the type identified under the Unified Numbering System as UNS N07001 and of 180000 psi axial tensile strength at room temperature, with maximum conditioning of parts at 1400 °F prior to room temperature testing.
E-25 General Standards for Aerospace and Propulsion Systems
The study of residual torque is necessary in various fields to ensure the safety and reliability of bolted joints. The present study aims to determine, experimentally, the decrease in torque applied to a nut used in the assembly of two polymeric components (POM - Polyoxymethylene). These components are part of the fuel supply module, responsible for supplying fuel from the tank to the engine. This reduction in torque initially applied is mapped to the end-of-life of the components and is used as an approval criteria in the audit procedures of the Robert Bosch company. The first component features an overmolded metallic screw, injected into POM. The mating part is also injection molded from POM and is assembled onto the first part, secured by tightening a metal nut. Due to the plastic-to-metal interface, it’s expected that there will be a reduction in the initially applied torque required to fasten the pieces together. The study was based on 5 steps: 1 Theoretical study on residual torque at the plastic-to-metal interface; 2 Verification of plastic component deformation due to applied torque; 3 Assembly of samples for practical tests; 4 Mapping of torque decrease in samples by time. In this case, a digital torque wrench was used; 5 Analysis of the data and determination of the residual torque range at the end of the product’s life. After the study was completed, it was determined a minimum residual torque, for the end of the product’s life, in this application. This criterion enables more accurate control in field part verification, improves product quality, and optimizes failures identification.
Spitaletti, Laís Scotelari, da Fonseca, Márcio Ghiraldelli
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This specification establishes the requirements for the following types of self-locking nuts in thread diameter sizes 0.1380 through 0.6250 inches: a Wrenching Nuts: i.e., hexagon, double hexagon and spline nuts. b Anchor Nuts: i.e., plate nuts, gang channel nuts, and shank nuts. The wrenching nuts, shank nuts, and nut elements of plate and gang channel nuts are made of a corrosion and heat resistant nickel-base alloy of the type identified under the Unified Numbering System as UNS N07001 and of 180,000 psi axial tensile strength at room temperature, with maximum conditioning of parts at 1400 °F prior to room temperature testing.
E-25 General Standards for Aerospace and Propulsion Systems
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Conventional drug delivery is often like cracking a nut with a sledgehammer. Whether the drug is swallowed, injected, inhaled, or absorbed through the skin, it ultimately diffuses to most parts of the body, including those where it isn’t needed — or where it even might cause harm.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
Threaded joints are considered the most basic of components. Although in use for over a century, significant problems still exist with their usage. Wheel bolt loosening in overloaded segments such as HD tippers and high-speed intercity buses poses a safety challenge for drivers, passengers, and pedestrians. Wheel nut loosening is a notable cause of service, fretting, and cracks in the mating components; contributing a significant chunk of warranty cost to the company. The need of the hour is to reinforce these joints while keeping resources at bay. This paper establishes a methodology for the evaluation and design of a safe wheel bolt joint interface including key parameters such as embedding, axial forces, and shear forces. It is necessary to obtain the minimum preload requirement for a wheel bolt joint to hold the clamped surfaces intact, which if not maintained otherwise would cause relative movement, play, shear load onto the bolt, and eventually failure. For physically auditing the pre-load the “on-off-on tightness checking method” has been incorporated. The study shows a significant increase in pre-load in geomate-coated nuts (M22X2.5 10.9 grade nuts binding rim, drum, and hub having PCD 335 mm) via optimizing the fastener finish and internal profile. A risk assessment study has been done involving bolt-nut grades, bearing stress, and thread stripping. Proof of concept has been established, verified for feasibility, and implemented in HD tippers. This approach saves any cost impact, development time, or changes in service operations, all being crucial to the industry. This proves to be a frugal and efficient way of strengthening bolted joints without disturbing size, PCD, or grade while maintaining modularity across platforms.
Raghatate, Shreyas, Sharma, Suchit, Sindal, Vinayak
Heavy vehicles such as construction machinery generally require a large traction force. For this reason, axle components are equipped with a final reduction gear to provide a structure that can generate a large traction force. Basic analysis of vertical load, horizontal load (traction force), centrifugal force, and torsional torque applied to the wheels of heavy vehicles such as construction machinery and industrial vehicles, as well as actual working load analysis during actual operations, were conducted and compiled into a load analysis diagram. The loosening tendency of wheel bolts and nuts that fasten the wheel under actual working load was measured, and the loosening analysis method was presented. The causes of wheel fall-off accidents in heavy trucks, which have recently become a problem, were examined. Wheel bolts are generally tightened by the calibrated wrench method using a torque wrench. The method is susceptible to variations in friction coefficient and tightening torque, and human error affects the tightening torque. Even if the tightening torque (initial clamping force) is insufficient, effective loosening prevention is considered necessary to prevent serious accidents such as wheels falling off. In forklifts, the number of hub bolts is limited due to space limitations, so hub nuts have a spherical or conical alignment structure that allows each nut and bolt to absorb the drive torque and slippage of the bearing surface. In wheel loaders, for example, there is space to install hub bolts, and the clamping force of the bolt sustained slippage of the bearing surface to prevent loosening and fatigue”
Hareyama, Soichi, Manabe, Ken-ichi, Kobayashi, Satoshi
E-25 General Standards for Aerospace and Propulsion Systems
This standard establishes the acceptance criteria for surface discontinuities as revealed by magnetic particle or liquid penetrant examination of nuts.
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
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