External Supermicrometer C - Model C250, C375, C500, C625

The Standard of Accuracy

If you're looking for a direct-reading bench micrometer and an electronic size comparator for use in the calibration laboratory or on the production floor, look no further, the third-generation External Supermicrometer Model C provides durability, digital accuracy, speed of measurement, and range of applications.  The Supermicrometer is the most popular bench micrometer in the world that can measure just about any manufactured precision OD part, turned part, or gages such as pins, plugs, and threads including API, NPT, NPTF, Dryseal, BSPP, BSPT, UN (Unified), M Profile (Metric), ACME, Buttress, UTS, UNC, UNF, UNEF, UNS, BSW (Whitworth), BA, BSC, BSF, BSP, to name a few.  The External Supermicrometer Model C is also the industry standard, 3-Wire Thread Measuring System.

The External Supermicrometer® Model C measures:

  • Your Precision Parts
  • Pin & Plug Gages
  • External Thread Gages
  • Dial / Test Indicators
  • Taper Threads - Pipe Threads (API Gages)
  • Dial Bore Gages
  • Cylindrical Setting Gages
  • Spheres 
  • Setting Masters / Setting Gauges   
  • Taps, Dies, and Cutting Tools
  • Gears / Splines
  • Feeler Gages   

Features & Benefits of the External Supermicrometer® Model C:

  • Heavy-duty cylindrical bed - Chromium-plated cylinder ensures long life and performance integrity and the rack and pinion drive eliminates movement during the measuring cycle
  • Adjustable pressure tailstock - Exclusive Electrolimit® tailstock offers adjustable pressure from 2 to 48 ounces (50 to 1350 g) for reliability and optimum performance of your Supermike.  Adjustable pressure is required for thread gage calibration and using 3-wires for Pitch Diameter (PD) measurement.  
  • Carbide-tipped measuring spindles - Non-rotating measuring spindles have long life, corrosion-free lapped anvils and are calibrated to ultra finish and precision.  A must for measuring thousands of pins or precision components.  
  • Elevating table - Adjustability allows for presentation of the part to the instrument in a non-influencing manner
  • Direct-reading, digital touchscreen readout box - Easy-to-read digital display provides direct reading in inch or metric units.  USB & Serial/RS 232 port is included. Optional Foot Switch is available to log the measurement value.
  • Calibrated analog meter - Establishes the reference zero for taking direct measurements from the microprocessor-based digital display
  • Digital module - Divides the measurement into 0.000010 inch (0.25 micron) increments for high resolution. If higher resolution is needed,the Model PC Supermic bench micrometer has 0.000001 inch (0.025 micron) resolution. 
  • Optional GageCal® software - Microsoft® Windows based software reduces data entry, eliminates transcription errors, and speeds up measurements of your digital Supermicrometer. GageCal automatically enters tolerances for taper threads, plugs, pins, straingt threads (calculates pitch/major diameter) and flags out-of-tolerance conditions. The most widely used bench micrometer software! 
  • Foot switch (optional) - Log the measurement value with a press of the foot switch (works with Digital Touchscreen Readout Box only)


Model / Part #
U 306005
Units English Metric English Metric English Metric English Metric
Accuracy 20 µinch 0.5 µm 20 µinch 0.5 µm 20 µinch 0.5 µm 20 µinch 0.5 µm
Repeatability 10 µinch 0.3 µm 10 µinch 0.3 µm 10 µinch 0.3 µm 10 µinch 0.3 µm
Measurement Range 0-10 inches 0-250 mm 0-15 inches 0-375 mm 0-20 inches 0-500 mm 0-25 inches 0-625 mm
Direct Reading Range 1 inch 25 mm 1 inch 25 mm 1 inch 25 mm 1 inch 25 mm
Measuring Force 2-48 oz. 50-1350 g 2-48 oz. 50-1350 g 2-48 oz. 50-1350 g 2-48 oz. 50-1350 g

*Model C-1000 also available: 0-40 inch (1000mm) measurement range

**CE compliant 0-10 inch (250 mm) External Supermicrometer Model C available: part# U307730-NR

NEW Accessory / Upgrade - Digital Tailstock Meter:

  • Compatible with Supermicrometer Model B, C, or PC
  • 1 millionth of an inch resolution [0.000001 inch (0.025 micron)]

Retrofit - Model B, Model C, Model PC