George Schuetz Director of Precision Gages

1 Dec 2003

Calibrating Gages: Your Place Or Mine?

Large companies can cost-justify hiring specialists in gage calibration and keeping equipment to perform calibration in-house. But for most shops, the economical approach is to hire a calibration service.

1 Nov 2003

A Probing Look At Probes

The capability of a measuring instrument often comes down to how the contact point interacts with the part being measured—that is, the probe or contact. There are some things to keep in mind when using a contact tip or probe arm as part of your measurement.

1 Oct 2003

Dimensional Collateral: Do Two Sines Equal A Cosine?

It is not just irony to say that comparative gages have their greatest accuracy at zero. Even though such a gage could provide a direct reading measurement, it is always best to use it as a comparator.

1 Sep 2003

Gage Block Verification

A QC manager asked if he could verify gage blocks in-house. “You always say the gage maker’s rule of thumb states that any gage used to verify another gage must resolve to ten times its accuracy,” he wrote.

1 Aug 2003

Getting My Stars Aligned

Gage design requires certain physical characteristics for reliable performance. A rigid and sound design, for instance, helps ensure that operators have as little influence on the measurement as possible.

2 Jul 2003

An Inside Look At Special Diameters

Sometimes we are faced with making critical inside diameter checks on parts that do not present themselves in a straightforward fashion. Usually these checks are on the inside of some type of bearing, and they can be almost any size.

1 Jun 2003

Micrometer Accuracy: Drunken Threads And Slip-Sticks

Whether it’s a screw thread or digital micrometer, the instrument’s level of precision depends on two factors: the inherent accuracy of the reference (the screw thread or the digital scale) and process errors. With a screw micrometer, accuracy relies on the lead of the screw built into the micrometer barrel.

1 May 2003

Advances In Air Gaging

Over the years, the tooling for air gaging has remained basically the same: steel tubes or rings with precision orifices that set up a pressure/distance curve when in use. As the orifice is restricted, flow is reduced and pressure builds up in the system.

6 Apr 2003

Reverse Polarity: Countering Your Clockwise Indicator

In the last issue, we looked at the advantages of balanced and continuous dial indicators. There are also measurements that require dial indicators with a counterclockwise dial.

2 Mar 2003

All Over The Dial

There are endless variations in the dials used on mechanical dial indicators. In most cases, though, they can be broken down into two distinct styles: balanced and continuous.

5 Feb 2003

Gaging Diameter Variation In Machined Holes

As tolerances for machined holes keep getting tighter, we are learning that no hole possesses a geometrically perfect, symmetrically round shape. No hole is likely to take on a perfect oval (two-lobed) form, either.

Holemaking 3 Jan 2003

Another Way To Square—Or Is It Perpendicular?—It Up

There are a number of tools available for shop personnel to evaluate the right angle relationship between two surfaces. The basic machinist square has a number of variations, the most common being the hardened steel square used to check right angles and set up milling and drilling machines.