Mitutoyo 422-231-30 Digimatic Blade Micrometer

Technical Overview

Precision 25-50mm digital outside micrometer with a 0.75mm Type A non-rotating spindle, ±3µm accuracy, and SPC data output for narrow groove measurement.

Key Features

Blade-shaped anvil and spindle (Type A) designed for measuring narrow grooves, keyways, and recessed dimensions
Non-rotating spindle mechanism prevents torsion and scratch damage on measured surfaces
Clear digital LCD display with a high-resolution readout of 0.001 mm
Ratchet stop mechanism provides constant measuring force (5–10 N) for superior consistency
SPC data output port enables direct data export for statistical quality control integration
ABSOLUTE (ABS) linear scale eliminates the need to reset the origin point at every power cycle
Equipped with Origin-Set, Zero-Setting, Data Hold, and Function Lock features

Technical Specification Matrix

Parameter	Value
Measurement Range	25 - 50 mm
Resolution	0.001 mm
Accuracy	±3 µm
Parallelism	3 µm
Blade Type	Type A (Hardened Steel)
Blade Thickness	0.75 mm
Measuring Spindle	ø6.35 mm
Spindle Pitch	0.5 mm
Measuring Force	5 - 10 N
Display Type	LCD (7.5 mm character height)
Battery Type	SR44 (1 pc., No. 938882)
Battery Life	Approx. 2.4 years under normal use
Data Output	Yes (SPC)
Frame Throat Depth (c)	50 mm
Frame Length (L)	90.7 mm
Physical Weight (kg)	0.57
Dimensions L x W x H (cm)	20 x 8.3 x 1.8

Industrial Applications

1. Shaft Retaining Ring Groove Quality Control

Verification of snap ring and retaining ring root diameters on high-precision electric motor and transmission shafts during high-volume machining processes.

Problem Solved

Standard micrometer anvils are too wide to penetrate retaining ring grooves, resulting in inaccurate measurement attempts. This tool directly reaches the bottom of narrow grooves down to 0.8 mm width with ±3µm accuracy.

Retaining Ring GrooveType A BladeShaft Machining QCNon-Rotating Spindle

2. Spline and Keyway Dimension Verification

In-process quality inspections of internal/external splines and drive keyways on power transmission gears within automotive component manufacturing.

Problem Solved

Ensures spline tolerances are maintained within precise engineering limits. The 5–10 N constant ratchet-stop force eliminates operator measuring force variance, and the thin blade profiles align precisely within complex gear geometries.

Spline MeasurementKeyway DimensionsConstant Measuring ForceGear Manufacturing

3. Polymer Film Extrusion Die Gap Calibration

Fine calibration and maintenance verification of the slot gap width on polymer film extrusion die lips to ensure uniform film thickness output.

Problem Solved

Measuring inside narrow slit die lips normally risks scratching the highly polished metal surfaces, which would ruin the extruded film's surface quality. The non-rotating spindle eliminates rotational friction against the die lips, and the 0.75 mm thickness allows deeper slot entry.

Die Gap CalibrationSlit Extrusion SlotNon-Rotating Spindle±3µm Accuracy