JLCMC Blog

Selection Principles

Screw Extractor Guide: How to Remove Broken Bolts and Studs

Key Takeaways A screw extractor (commonly called an easy out) is a hardened tool for removing broken fasteners, gripping them through spiral flutes, straight flutes, or multi-spline teeth depending on its design; many common types engage when turned counterclockwise. The workflow is drill a pilot hole, then turn the extractor counterclockwise; a left-hand drill bit often does the whole job on its own, backing the broken piece out while drilling. Broken-bolt and stripped-screw are different problems: a......

Nov 03, 2026

Selection Principles

How to Measure Thread Size: Pitch, TPI & Bolt Threads

Key Takeaways How to measure thread size comes down to two numbers: the major diameter (measured across the thread crests) and the pitch, which is threads per inch (TPI) on inch threads and millimeters between crests on metric threads. A thread pitch gauge is the purpose-built tool: fan out the blades, find the one whose teeth mesh with no visible gaps, and read the size stamped on it. Measure the major diameter with a caliper across a full thread, away from the chamfered end; the reading narrows the ......

Nov 02, 2026

Fasteners & Hardware

Polyurethane Bumper Energy Calculation: Impact Kinetic Formulas, Stroke & Duty Cycles

Key Takeaways Impact energy depends on contact velocity squared, so a small speed change can materially alter the stopping event. Physical bumper height is not the same as permitted compression or usable stopping distance. Include work from a drive force that continues during compression, plus gravity or rotational effects where applicable. Hardness describes indentation resistance; it is not an energy rating or a complete force-deflection curve. Repeated impacts require a duty assessment as well as a......

Nov 02, 2026

Fasteners & Hardware

Rubber Vibration Isolator Natural Frequency Calculation & Rigid Bypass Troubleshooting Standards

Key Takeaways Trace every mechanical connection between the isolated assembly and its surroundings, including services and guards. Compression, shear and tension are different loading conditions; use the data for the intended direction. A mount must be loaded appropriately, not merely kept below its maximum capacity. Keep deliberate retention hardware compatible with the movement needed for isolation. Compare vibration before and after changes at consistent operating conditions and measurement locatio......

Nov 02, 2026

Selection Principles

Advantages and Disadvantages of Articulated Robots

Introduction Articulated robots offer high flexibility, multi-axis movement, and the ability to handle complex manufacturing tasks, making them suitable for a wide range of automated applications. However, their advantages come with trade-offs, including higher initial investment, programming complexity, maintenance requirements, and safety considerations. Understanding these advantages and disadvantages helps manufacturers determine when articulated robots provide practical value and when other autom......

Nov 02, 2026

Fasteners & Hardware

What Is a Torx Screw? Star Drive and Security Torx Explained

If you have seen a screw with a six-point star recess, you have likely seen a Torx screw. So, what is a Torx screw? It is a screw with a six-lobe drive profile. You use a Torx bit to turn the screw. People often call this shape a star drive because of its six-lobe form. The standard Torx profile has six smooth, round lobes rather than sharp points. Other six-lobe drive profiles may look similar, but their dimensions can differ, and their tools may not be interchangeable. This shape gives the tool broa......

Oct 27, 2026