Mitutoyo 422-232-30 Digital Blade Micrometer

Technical Overview

Digital blade micrometer (50-75mm range, ±3 µm accuracy) with non-rotating spindle, Type A 0.75mm hardened steel blade, ratchet stop, and SPC data output.

Key Features

Blade-shaped anvil and spindle (Type A, 0.75 mm thickness) specifically designed to measure groove diameters of shafts, keyways, and other hard-to-reach recesses.
Non-rotating spindle design eliminates torque and torsion on the measured workpiece, preventing surface wear or deformation on delicate parts.
Integrated ABSOLUTE (ABS) linear scale maintains the origin position after power-off, eliminating the need for daily zero-point recalibration.
Ratchet stop mechanism provides a consistent measuring force of 3 to 8 N for accurate, highly repeatable user-independent readings.
Digimatic SPC data output capability enables quick, error-free measurement logging and integration with quality control networks or PC terminals.
Large LCD screen with 7.5 mm high characters displays measurements with a crisp digital resolution of 0.001 mm.
Built-in function alarms for low battery voltage and counting value composition errors to prevent faulty measurement readings.
Supplied with a setting standard bar (50 mm), adjustment spanner, SR44 battery, and a fitted plastic protection case.

Technical Specification Matrix

Parameter	Value
Measurement Range	50 - 75 mm
Resolution	0.001 mm
Maximum Permissible Error (J MPE)	±3 µm
Parallelism	3 µm
Measuring Face Type	Type A (Blade-shaped, hardened steel)
Blade Thickness	0.75 mm
Blade Depth	6.5 mm
Spindle Type	Non-rotating spindle
Spindle Diameter	6.35 mm
Spindle Pitch	0.5 mm
Measuring Force	3 to 8 N
Constant Force Device	Ratchet Stop
Data Output	Yes (Digimatic SPC)
Power Supply	1x SR44 Battery (Silver Oxide)
Battery Life	Approx. 2.4 years under normal use
Display	LCD (7.5 mm character height)
Waterproof Rating	None (Not water-proof / Not IP rated)
Physical Weight (kg)	0.47
Dimensions L x W x H (cm)	20.5 x 4.5 x 8.5

Industrial Applications

1. Automotive Transmission Shaft Keyway Inspection

In the manufacturing of automotive splined shafts and transmissions, keyway dimensions must be closely inspected. Due to standard flat-anvil micrometers being too wide to access narrow recesses, the 0.75 mm Type A blade of the 422-232-30 easily slides to the groove floor to verify diameter accuracy.

Problem Solved

Eliminates assembly mismatch of shaft keys and mating hubs by allowing precise direct measurement of recessed groove diameters with ±3 µm accuracy.

Keyway DepthTransmission ShaftsBlade AnvilGroove Diameter

2. Delicate Forming Roller Surface Verification

Inspecting polished forming rollers in rolling mills requires measuring groove widths without causing cosmetic damage. The non-rotating spindle of this micrometer descends directly without spinning, removing friction on high-precision workpiece faces.

Problem Solved

Prevents scratching, shearing, and torsional deformation of delicate, soft, or high-finish metals during dimensional inspections.

Non-Rotating SpindleForming RollersTorsional StressPolished Surfaces

3. Automated Quality Control SPC Integration

During high-volume component machining, part measurements must be captured quickly. The 422-232-30 outputs real-time measurement values via SPC directly into systems like MeasurLink for instant digital cataloging.

Problem Solved

Replaces manual hand-written metrics with error-free, single-click digital logs, boosting output volume in automated production facilities.

SPC Data OutputStatistical Process ControlMeasurLinkDigimatic