Gaging All Things Round: Solutions

Feb. 4, 2009 - PRLog -- More often than not, the biggest battle in controlling quality is in measuring the ID and OD of parts. Ring Gages and Plug Gages work well when determining if two parts will fit together. The problem with this method of gaging is that deviation from roundness and size are not measured or monitored. On the plus side, these gages are fairly inexpensive and easy to use; the gages either go on the part or they don’t.

There are many alternatives to attribute gages and as one might expect, there are a wide variety of solutions for measuring inside and outside diameters. Some considerations when choosing a gaging solution are your tolerances, surface finishes, part length, and depths. Remember the ten-to-one rule. If you have a tolerance of +/-0.005 inches, you will need a gage that is accurate to +/-0.0005 inches. Keep in mind that beyond this, you might have a GR&R (Gage Repeatability and Reproducibility) requirement and without fixed and repeatable location points, it is very difficult to pass a GR&R for an ID/OD dimension; placing the part in the gage with the same orientation every time is almost impossible.

The next step is to determine frequency of use, plant location of check, and environment. Birdsall Tool & Gage (http://www.birdsalltool.com) has plenty of experience in matching the right gage to your application. With a part print and a short survey we are able to present several options that take into consideration the total gaging cost; a blend of flexibility, pricing, calibration requirements, operator skills, and recyclability.

Measuring ID and OD size is not always enough. Many times these checks are tied in with other critical Dimensions. Fixture and Bench Gages have the ability to check runout, concentricity, and most other relationships. With the advent of computers, the cost for multiple related tolerances has greatly decreased. BTG offers several computer based solutions with easy to use programmable controls. It is also very easy to recycle the electronics from one gage to another or to change the function of the gage when product engineering changes occur. Even for low production levels it isn’t necessary to run parts back and forth to a centralized CMM machine or layout room. Gaging systems with complicated checks are now attainable for most gaging budgets.

David Birdsall President of Birdsall Tool & Gage Co. designs and builds fixture gages, fixed gages, inspection and gaging accessories, ring gages, plug gages, thread gages, snap gages, electronic gages, mechanical gages, data collection gages, masters and setting gages, CMM fixtures, special tools and tooling with customer satisfaction in mind. Call 248-474-5150 for more information about our company.

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Birdsall Tool and Gage Co. designs and builds fixture gages, fixed gages, inspection and gaging accessories, ring gages, plug gages, thread gages, snap gages, electronic gages, mechanical gages, data collection gages, masters and setting gages.