Peak Innovations Engineering

When the pressing application requires a force of 10 tons or more, manufacturers can count on hydraulic, hydropneumatics and pneumohydraulic presses. Some assembly technologies evolve too fast or too slow, while others change at a pace that’s just right. Hydraulic presses belong in the latter category, according to some suppliers, and that’s a good thing. The biggest area of growth for pressmasterhydraulic press technology lies in the controls system. Automotive, aerospace and medical manufacturers want and need advancements in operator control, press-data acquisition, process monitoring, quality control and maintenance scheduling. These benefits nicely complement the hydraulic press’s ability to generate high force over a small area and equally throughout the stroke. All of these capabilities are important to companies with hydraulic pressing applications, especially those that require 10 tons or more of force. Pure Power Pressmasterhydraulic press have been used on assembly...

Fastener assemblies are simple machines but they are often used in very complex structures.  When working in situations where joint failure is catastrophic making assumptions about how well they are working is not an acceptable method of operation.  In these cases liability and refastening costs are so high that it is essential to understand the hows and whys of fastening with bolts and nuts to answer torque and tension relationship . It is recognized we measure torque when tightening threaded fasteners only because measuring bolt tension, the more important quantity, is much more difficult. The torque and tension relationship created from the resulting bolt elongation is most commonly described by T = F*K*D where T is torque, K is the nut or friction factor (nut factor for this article), D is the bolt diameter and F is the bolt tension or preload. Less common is a discussion of how this equation was derived, in particular the origin of the nut factor. Because...

The fundamentals of using ultrasonic bolt tension meter for bolt strain measurement, detecting change in the time required for a pulse of energy to travel the length of the fastener after elongation, can be performed with very good resolution and repeatability. The challenge is utilizing this core capability in a manner such that the resulting calculation of boll tension is also accurate and repeatable. Traditionally, the primary barriers to this have been in three areas maintaining a stable bolt-sensor interface where the pulse passes into and out of the fastener, accounting for the influence of temperature on the measurement and providing an accurate means of converting a given change in the pulse’s time-of-flight (TOF) to usable units of tension or load. The last is generally refined to as calibration. Recent developments that affix the sensor to the fastener, leaving the bolt-sensor interface a fixed and permanent condition, have largely solved the interface instability prob...