Items Tagged with 'ASME standard'

This paper presents Method 5, which controls the Probability of False Acceptance using Specific Risk, and Method 6, the Managed Guard-Band Strategy by Michael Dobbert, using Global Risk. Choosing the right rule is essential for managing risk and improving measurement accuracy, with examples illustrating how these rules can reduce costs.

Chris Cantrell, senior managing director of standards and engineering services at ASME, explains how standards can help companies advance, innovate, and access a broader market base.

Taper Pipe Threads are one of the more challenging threads to produce and measure. The ASME B1.20.1-2013 Pipe Threads, General Purpose (Inch) is the current standard that covers both the part thread specifications and the gages for NPT, NPSC, NPTR, NPSM and NPSL threads.

In Geometric Dimensioning and Tolerancing (GD&T) there has been a long-standing conflict between the worlds of specification and measurement. The goal of specification is to ensure that components will function; the goal of measurement is to ensure that manufactured components meet those functional requirements. 

Screw thread inserts (STI) require the threaded hole to be inspected prior to inserting the threaded insert or coil. The dimensions and tolerances for the gages used to inspect these threads have been a bit confusing over the past 30 years. 

Amongst the pile of tools in my garage is a nice six-inch caliper, which I use for the occasional minor project around the house. And even though I work in one of the finest dimensional calibration laboratories in the country, where we calibrate thousands of calipers every year, my own personal caliper has not been calibrated in over 20 years.

GD&T is the only tool we have with which to manage machine part geometry perfectly. In particular, it’s the only tool we have with which to impose truly functional limits of imperfection on machine part features and actually guarantee assembly and operation prior to drawing release.