Ultrasonic metal welding is a solid-state welding process that produces coalescence through the simultaneous application of localized high-frequency vibratory energy and moderate clamping forces. This article discusses the parameters to be considered when selecting a suitable welder for ultrasonic metal welding. It details the personnel requirements, advantages, limitations, and applications, namely, wire welds, spot welds, continuous seam welds, and microelectronic welds of ultrasonic metal welding.

This article provides an overview of the relationships between torque, angle-of-turn, tension, and friction and explains how they are measured and evaluated. It focuses on the principle, test equipment, procedure, evaluation, and test report of various testing methods, namely, friction coefficient testing, torque tension testing, locknut testing, and angular ductility and rotational capacity tests. The article reviews the basic methods and fundamental principles for mechanical testing of externally and internally threaded fasteners and bolted joints. The test methods for externally threaded fasteners include product hardness, proof load, axial and wedge tension testing of full-sized products, tension testing of machined test specimens, and total extension at fracture testing. Product hardness, proof load, and cone proof-load test are the test methods for internally threaded fasteners. The article concludes with a description of torque-angle signature analysis and the specification of measurement accuracy for torque and clamp force.

Seals are mechanical components that prevent the leakage, diffusion, transfer, or mixing of different liquid, gas, solid, and multiphasic substances. This article begins by discussing the classifications of seals: static and dynamic. Static seals involve both self-energizing elastomeric materials such as O-rings, which merely react to a sealed fluid pressure, and passive materials that require clamping forces to achieve sealing, such as gaskets. The types of dynamic seals include rotary seals and reciprocating seals. The article describes the factors affecting seal wear and failure. It provides a list of some common seal wear modes and failures, namely abrasion, cavitation damage, chemical attack, compression set, corrosion, damage during abrupt decompression, dieseling damage, extrusion damage, installation damage, spiral or rolling damage, and vaporization damage. The article concludes with specific recommendations for reducting of seal friction and wear.

A fixture is a special workholding and supporting device designed and built for a particular part or shape that can be made by using standardized components, such as drill bushings, locating buttons, and clamping devices. This article provides a discussion on optimum fixture design and describes the clamping methods, namely, manual clamping, pneumatic clamping, and hydraulic clamping, and their specific principles. It presents an overview on modular fixturing for limited production. The article concludes with information on cost factors in fixturing.

The cold chamber die casting process is used with higher-melting-point alloys such as aluminum and magnesium. This article discusses the component design of the cold chamber high-pressure die casting machine. It reviews the process parameters of cold chamber die casting, incuding the shot profile, intensification phase, and component size.

This article discusses the properties of threaded fasteners made from carbon and low-alloy steels containing a maximum of 0.55% carbon. It provides guidelines for the selection of steels for bolts, studs, and nuts intended for use at temperatures between -50 and 370 deg C. The article also discusses steels rated for service above 370 deg C and describes internationally recognized grade designations. The specifications provided can be used to outline fastener requirements, contro