Mitutoyo 103-137 Outside Micrometer

Technical Overview

Analog precision device featuring a 0-25mm range, 0.01mm graduation, ±2µm accuracy, carbide-tipped faces, and a ratchet stop for uniform measuring force.

Key Features

Measuring range of 0 to 25 mm with 0.01 mm graduations
High accuracy of ±2 µm with 0.6 µm flatness and 2 µm parallelism
Carbide-tipped spindle and anvil with micro-lap finish for exceptional wear resistance
Ratchet stop mechanism provides constant, uniform measuring force (5 to 10 N)
Hammertone green baked-enamel finished frame for lightweight, robust workshop durability
Clear, satin-chrome finished sleeve and thimble (ø18 mm) with anti-glare scales
Spindle lock (ø6.35 mm spindle, 0.5 mm pitch) for locking the measurement in place

Technical Specification Matrix

Parameter	Value
Measuring Range	0 - 25 mm
Graduation	0.01 mm
Accuracy	±2 µm
Flatness	0.6 µm
Parallelism	2 µm
Measuring Force	5 - 10 N
Spindle Diameter	6.35 mm
Spindle Pitch	0.5 mm
Measuring Face Material	Carbide-tipped, micro-lap finish
Frame Finish	Hammertone green, baked-enamel finish
Scale Finish	Satin chrome finish
Thimble Diameter	18 mm
Spindle Lock	Equipped
Constant Force Device	Ratchet Stop
Display Method	Analog (Vernier)
Physical Weight (kg)	0.18
Dimensions L x W x H (cm)	13.7 x 6.6 x 2.5

Industrial Applications

1. Precision Automotive Valve Shim Inspection

Measuring the thickness of automotive engine valve shims to ensure precise clearance adjustment during valvetrain assembly. The 0-25mm measurement range and 0.01mm graduation allow technicians to confirm exact thickness variations.

Problem Solved

Prevents incorrect valve clearance which causes performance loss, noise, or engine wear. The carbide-tipped faces resist wear against hardened steel shims, while the ratchet stop ensures operators apply identical measuring force, preventing measurement bias.

Valve ClearanceShim ThicknessEngine AssemblyCarbide-TippedRepeatable Measurement

2. Machined Shaft Diameter Quality Control

Verification of external diameters of precision-turned steel shafts and pins within a 0-25mm envelope directly on the workshop bench.

Problem Solved

Ensures shaft diameters meet h7 or h8 tolerances before assembly with bearings. The ±2µm accuracy allows rapid confirmation of diameter conformity, and the spindle lock retains the measurement value for inspection logging.

Shaft ToleranceBearing FitTurned PartsOutside DiameterQuality Control

3. Sheet Metal and Shim Stock Thickness Verification

Checking the thickness of sheet metal, copper gaskets, or metal foils (0.1mm to 5mm thickness) prior to punching or assembly.

Problem Solved

Avoids tool damage in punching dies due to feeding oversized material. The constant-force ratchet stop (5-10N) prevents the micrometer from compressing softer metal foils, securing a true physical thickness reading.

Material GaugeSheet Metal ThicknessGasket InspectionDeformation PreventionRatchet Stop