Archives July/August 2009 : Tool of the Month

Tool of the Month:

Vernier Caliper

Many times customers will purchase wire and sheet and ask how will they know what gauge the metal is, if it were to get mixed up. While the Browne & Sharpe Gauge (also known as the "gauge gauge") is made especially for measuring the thickness of wire and sheet, vernier calipers are a great alternative. While most are a bit more pricey than the B&S gauge, they are much more versatile.

Calipers are a basic measuring tool used in MANY different fields, from a machinists precision tool to a device used to measure body fat in a doctor's office. Calipers are a kind of device used to measure the distance between two opposing sides. The tips of the caliper are adjusted to fit across the points to be measured, the caliper is then removed and the distance read by measuring between the tips with a measuring tool, such as a ruler.

Vernier calipers are a specialized type of caliper that includes not only the measuring tool built into the caliper but a vernier scale for a more precise measurement. A vernier scale is a sliding secondary scale that is used to indicate where the measurement lies when it is in between two of the marks on the main scale.

Brass Sliding Caliper
The most basic vernier caliper used in jewelry is the brass sliding gauge. This brass caliper measures external dimensions in metric only (millimeters), and is slightly less precise than a proper vernier caliper. But it is inexpensive and quick to use, therefore handy for general use and great for your first caliper. It also can be used to check for rightness of an angle. The brass millimeter gauge has a small knob on the main sliding scale for easy sliding when measuring. They come in two different lengths, 60mm and 80mm, priced at $9.40 and $11.50, respectively.

Vernier Caliper
Other than measuring external dimensions, the standard vernier caliper has a few more measuring capabilities than the brass sliding gauge. They have an upper jaw to measure internal dimensions (like the inside diameter of tubing) and a slender depth probe, attached to the moveable head and slides along the center of the body of the caliper, that will measure deep groves and areas that would prove difficult to measure otherwise. The standard vernier caliper also includes both metric and inch measurements on the upper and lower part of the scale. It also has a locking feature to easily set your measurement and then scribe a measured line onto your project. The Vernier Caliper that JFF carries is a steel bodied caliper with a smooth track, made in Poland. It is priced at $69.75.


Dial Caliper
An improvement to the Vernier Caliper is a Dial Caliper. The dial measures in small increments for precision measuring. Usually only in one scale, inch or metric. However, the dial is much easier to read and has the same measuring capabilities as the Vernier Caliper. The Dial Caliper has a hard plastic body and is made in Switzerland, priced at $38.70. This caliper in particular does not have a locking mechanism, as the hard plastic body is not enough to leave a scribe line.


Digital Caliper
The easiest to read, and most accurate caliper is the Digital Caliper. This caliper has replaced most all other measuring tools in my jewelry studio (except of course a ruler). The Digital Caliper is the bees knees and the "Rolls Royce" of calipers. While it has a large digital screen for reading the measurement, it also has the capability to switch from inches to millimeters with the press of a button. The Digital Caliper has all the same measuring and locking features at the Vernier Calipers, but takes out the guess work of accurate measuring. The Mitutoyo Digital Caliper is made in Japan with a steel body and measures to the 0.01mm and 0.0005", making this the most precise Caliper. The Mitutoyo comes in two different sizes, 4" (100mm) and 6" (150mm), priced at $129 and $139, respectively.