Starrett 121AZ Long Range Tubular Inside Micrometer, 32-57″ Range, .001″


With a measuring range of 32-57″, the Starrett 121AZ has a capacity beyond most other micrometers. Easily measure depth using a micrometer specifically designed for large internal measurements.

Add 5-7 days for calibration

Product Description

The Starrett 121AZ Long Range Tubular Inside Micrometer is an accurate precision instrument that measures inside diameters. It consists of a micrometer head mounted at the end of a tubular holder with two rods for measuring the outside diameter. The rods have inch graduations, and the holder has a large, knurled clamping nut.

Easily secure measurements and prevent slipping when adjusting rod length during use. Together with the collet, the design ensures an extremely tight grip on the rods in any setting.

Made of steel, the 121AZ has a rigid, lightweight design, so it’s easy to handle and store. The satin-chrome prevents glare when reading measurements, while the nickel-plated finish adds durability.

It includes a graduated measuring rod in a wooden case.

Features and Specifications

  • Insulated rod holder to eliminate expansion by heat when handheld
  • Attractive nickel-plated finish; satin-chrome finish on the micrometer head reading surfaces
  • Accurately graduated rods in inches – micrometer head in
    thousandths of an inch
  • Hardened and ground anvils. All rod anvils are adjustable.
  • Quick, easy adjustment for micrometer screw
  • Consists of a micrometer head mounted at the end of a tubular holder
  • The final size reading in thousands of an inch is through the micrometer head


  • Manufacturing
  • Machining
  • Automotive
  • Aerospace
  • Construction
  • Inspection
  • Industrial
  • Shipbuilding


  • Measure the internal diameter of tubes, pipes, etc.
  • Measure the size of bearings, shafts, and other cylindrical objects
  • Check threaded holes for burrs or rough spots
  • Inspect tubes

About Starrett

The L.S. Starrett Company is a world leader in precision measuring tools and instruments. Since 1880, they have been an industry standard. Starrett’s high quality and durability have made the brand an industry standard for decades. They produce products for various industries, including aerospace, automotive, manufacturing, and commercial construction. Today, they’ve expanded into metalworking, making saw blade products for manufacturing operations worldwide.

Additional Information

Weight 6.15 lbs
Dimensions 36.4 × 4.5 × 2.6 in




Movement of Screw


No of Measuring Rods


No of Micrometers


Rod Diameter


Operation Type






Thimble Type


Lock Nut Type



Wooden Case

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