For over 50 years Dorsey Metrology International has been manufacturing and selling precision measuring equipment such as dial indicators, bore gages, large diameter gages and snap gages, just to name a few.
Since 1986 we also have been perfecting our high quality optical comparator line. To view more information on our wide variety of products please visit the individual product pages.
Snap Gages are among the oldest and simplest of all gages. As a general rule, snap gages should be used whenever possible where external measurements of diameters or widths of part are required. The first type of snap gage was the fixed or limit snap gage. These snap gages had limited adjustability and could only confirm that a part was within tolerance, but could offer no variable data. Today’s adjustable dial snap gages offer flexibility and accuracy. Most dial snap gages have 1" (25mm) of adjustment and can be quickly and easily set to any size within that range. Variable data is accomplished by the use of a dial or digital indicator, or LVDT.
The main advantage of dial snap gages is that accurate measurements are not dependent on operator skill or a sense of feel as is true with a micrometer. The snap gages are literally "snapped" on to the part and a reading can be taken in a matter of seconds. A wide variety of snap gages anvils are available to check OD grooves, and other special shapes.
Snap gages are made in different designs with regard to indicator's measuring range, its accuracy and smallest graduation of the dial. A typical snap gage consist of a C-frame with gaging members in the jaw of the frame.
SSG style snap gage
Bore gages, unlike snap gages, are measuring or transfer instruments that are used in the process of dimensional measurement or assessment of the internal diameter of components. Bore gages use the principle of two point gaging and three point centralization. Major bore gage application is to quickly inspect hole diameters as well as to detect and measure all kinds of bore conditions such as taper, bell-mouth and out-of-roundness. Dial bore gages in no way depend upon a sense of "feel" as is the case with non-indicating types. Machine operators find them to be particularly useful in making quick, accurate adjustments to bring work-pieces within tolerance. In this application, the reading on the dial tells the exact amount of tool correction needed and eliminates uncertain, "creep-up" methods of making adjustments.
The regular type dial bore gages are intended for the usual situation where there is ample space in front of the bore opening. For gaging in restricted spaces, or to faciliate readings where other limitations are imposed, Pistol-Grip, Vertical, Flush-Mount, Perpendicular and Right angle style bore gages are available.
Standard style dial bore gages
Optical comparator is a non contact inspection instrument that applies the principle of optics to magnify and project the image of an inspected part. Optical inspection instruments allow the inspection of a part while the part is actually moving and being machined on the machine tool. Light source emits light beam that travels through prism and projects the shadow of an object onto a screen a few feet away so it can be compared with a chart showing tolerance levels for the part.
Various optical comparators screen sizes are available to Dorsey's customers, from 12" to 80". When selecting optical comparator screen size, it is important to determine how much of the part must be viewed at one time.
Dorsey's optical comparators with digital readouts eliminate operator subjectivity and increase repeadability and accuracy. When using optical comparators with readout system it is not necessary to view the entire part to measure it.
Optical Comparator
Dorsey Metrology manufactures wide array of inspection instruments. From very simple fixed snap gages and limit snap gages to more complex custom designs. Visit our product pages for more information about dial indicators, optical comparators, large diameter gages, bore gages, snap gages and the rest of our entire line of products.