Fowler 52-229-778 Caliper, Micrometer & Test Indicator Set, 0.001" Caliper,0.0001" Micrometer, and 0.0005" Test Indicator Graduation

The Fowler 52-229-778 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 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 white 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.

The black-face dial test indicator includes a 0-15-0 balanced dial test indicator with a 0 to 1" measuring range and 0.0005" graduation interval, a jeweled movement with an auto-reverse mechanism, a 210-degree swivel range, two dovetail mounts, and a 5/32" stem mount, and is designed to measure surface variations in narrow or recessed areas. An adjustable bezel and dial zeros the reading at any location. Jeweled bearings and an auto-reverse mechanism provide smooth lever action. Three contact points have a 0.5" length and 0.040", 0.080" and 0.120" ball diameters that provide durability for a range of surfaces, and the contact point swivels 210 degrees to reach a variety of locations. Two dovetail mounts on the front and back of the indicator and a 5/32" stem mount on the top allow the indicator to be mounted from the top, front, and back.

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.

Dial 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 measure inside, outside, and step measurements in standard or metric units. 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 to take measurements. A circular dial indicator is fixed to the movable jaw on a toothed gear rack that transfers movement of the jaws to the dial needle. The base measurement is taken from the long beam, which provides the initial whole measurement in inches or centimeters, and added to the dial 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 calipers, dial calipers are more durable, but are more susceptible to shock damage and prone to getting dirt in the gears, which can cause accuracy problems. Vernier calipers are more durable than dial calipers because they do not have internal moving parts, but they can be more difficult to read. Dial calipers are commonly used in fields such as metalworking, mechanical engineering, machining, and carpentry.

Test indicator gauges, also called gages, are precision instruments that measure short linear distances. They are commonly used for detecting deviations from tolerance limits, such as small variations in flatness or height of an inspected workpiece, and permit measurement in narrow grooves or small bores. A test indicator gauge consists of a ball-tipped contact point on a levered arm, also called a measuring insert, which pivots from a hinge point. The reading indicates the degree of angular displacement of the arm. Test indicator gauges are commonly used in manufacturing, machining, and mechanical engineering. Standard test indicators measure the displacement of the arm perpendicular to the axis of the indicator. Dial and electronic indicators are very similar to test indicators, except that the axis of measurement is parallel to the axis of the indicator. Test indicators can be analog, with a mechanical dial, or electronic, with a digital display. Some electronic models transfer the data electronically to a computer for recording and potential manipulation.

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 52-008-706 white-face caliper
• Fowler 52-562-778 black-face test indicator
• 0.040" contact point
• 0.080" contact point
• 0.120" contact point
• 3/8" dovetail clamp
• 5/32" dovetail clamp
• Case