Fowler 52-229-710 Caliper & Micrometer Set, 0.001" Caliper and 0.0001" Micrometer Graduation

The Fowler 52-229-710 caliper and micrometer set includes a Vernier-scale outside micrometer with a 0 to 1" measuring range, a black-face dial caliper with a 0 to 6" measuring range, and a fitted case. The Vernier-scale outside micrometer has a 0 to 1" measuring range and a flat anvil/spindle pair for general purpose measuring. The Vernier scale has 0.0001" microfine graduation intervals on a satin chrome finish for precise readings. The positive locking nut on the spindle locks measurements in place for accurate readings and the zero adjustment on the sleeve ensures accurate measurements. The anvil/spindle pair has a 0.256" diameter hardened, precision-ground, and micro-lapped carbide measuring faces with 0.00003" flatness and 0.0005" parallelism to provide accurate measurements. Friction thimble applies constant force for repeatability between users. Friction-style thimbles are suitable for one-handed operation and stop turning when the spindle comes into contact with the workpiece, providing constant force for consistent measurements between operators. The ratchet stop-thimble can be used independent of the friction thimble. The heat-insulated frame helps reduce temperature-related expansion or contraction, providing accurate measurements, and protects the operator's hands from heat.

The shockproof stainless steel dial caliper has a black face and dial graduations of 0.001" with 0.001" accuracy, and beam-engraved 0.1" graduations, and is used for measuring inside dimensions (ID), outside dimensions (OD), depth, and step. The caliper measures 0.10" per revolution of the dial. The caliper has shockproof anti-backlash control, a sliding jaw with a lock, and a covered rack. Shockproof anti-backlash control with a heavy-duty spring provides increased accuracy over standard gear configurations. Backlash is the amount of clearance between mated gear teeth in the caliper controls that prevents the gear teeth from jamming. A knurled lock screw holds the sliding jaw in position to help ensure a consistent measurement. A covered rack prevents dirt and debris from clogging the gear, and helps prevent measurement errors. A thumb-operated fine adjustment roller allows for one-handed use. The hardened stainless steel components, including the bar, measuring surfaces, rack, gears, and depth rod, offer corrosion resistance, increased accuracy, and long life. Self-contained movement eliminates gear misalignment, while the dual pinion drive mechanism reduces wear on the rack and pinion. An adjustable dial enables setting zero. The hardened stainless steel is polished to a satin chrome finish, to help prevent glare.

Micrometers are precision measuring instruments that use a calibrated screw to measure distances. These measurements are translated into large rotations of the screw that are then able to be read from a scale or a dial. Micrometers are typically used in manufacturing, machining, and mechanical engineering. There are three types of micrometer: outside, inside, and depth. Outside micrometers may also be called micrometer calipers, and are used to measure the length, width, or outside diameter of an object. Inside micrometers are typically used to measure interior diameter, as in a hole. Depth micrometers measure the height, or depth, of any shape that has a step, groove, or slot.

Vernier calipers are measuring instruments commonly used for inspection in manufacturing to provide the precise measurements of an object. A pair of jaws attached to a long beam with a marked scale is used to take inside, outside, and step measurements. An additional depth probe slides along the beam to take depth measurements. One jaw is fixed to the end of the scale, while the other jaw slides along it with gearless precision to take measurements. The main scale is engraved directly on the beam while the vernier scale is engraved on the slider mechanism. The base measurement is taken from the long beam, which provides the initial whole measurement in inches, centimeters, or millimeters. To obtain the total measurement, the base reading is added to the vernier scale reading, which provides fractional measurements in inches or millimeters. A locking mechanism provides the ability to take differential measurements for determining the difference in measurements between two objects. Compared to digital and dial calipers, vernier calipers are more durable because they do not have internal moving parts, and are less prone to inaccuracy caused by shock, debris, and other contaminants, but they can be more difficult to read than digital and dial calipers. Vernier calipers are commonly used in fields such as metalworking, mechanical engineering, machining, and carpentry.

The Fred V. Fowler Company manufactures inspection and measurement instruments such as electronic indicators, calipers, bore gages, and digital scales. The company, founded in 1946, is headquartered in Newton, MA.

What’s in the Box?

• Fowler 52-229-201 Vernier-scale outside micrometer
• Fowler 52-008-707 black-face caliper
• Fitted case