Mitutoyo 103-139-10 : Outside Micrometer Range 50-75mm
The Mitutoyo 103-139-10 is a precision outside micrometer covering the 50–75 mm measurement range with 0.01 mm graduation, manufactured by Mitutoyo — the world's leading maker of dimensional measuring instruments. Part of the reliable 103 series, this micrometer is built for measuring larger shafts, couplings, flanges, and turned components that fall in the 50–75 mm range — common dimensions in CNC turning, heavy machining, and industrial maintenance across the UAE.
Conforming to ISO 3611 and DIN 863, the 103-139-10 delivers ±2 µm accuracy with carbide-tipped, micro-lapped measuring faces for consistent full-face contact and long service life. It ships with a 50 mm setting standard for zero-point calibration, a spanner key, and an inspection certificate — ready for immediate use on the shop floor or in the quality lab.
✦ Key Features
Carbide-Tipped Measuring Faces — Micro-lapped to 0.6 µm flatness. Resists wear from repeated contact with hardened steel, stainless steel, and aluminium workpieces.
50 mm Setting Standard Included — Enables precise zero-point calibration before every measurement session, maintaining traceable accuracy across shifts.
Ratchet Thimble — Applies consistent 5–10 N measuring force on every reading, removing operator-dependent variation.
Spindle Lock — Clamp the spindle at any position for comparative measurements or gauge setting without losing the reading.
Satin Chrome Finish — Anti-glare barrel and thimble for easy reading under shop-floor lighting conditions.
Heat-Insulating Plates — Minimise thermal expansion from hand contact — particularly important on larger-frame micrometers used in extended measurement sessions.
📐 Technical Specifications
| Model | 103-139-10 |
| Range | 50–75 mm |
| Graduation | 0.01 mm |
| Accuracy (MPE) | ±2 µm |
| Flatness | 0.6 µm |
| Parallelism | 2 µm |
| Measuring Faces | Carbide-tipped, micro-lap finish |
| Spindle Diameter | ø6.35 mm (≤300 mm) / ø8 mm (>300 mm) |
| Spindle Pitch | 0.5 mm |
| Thimble Type | Ratchet |
| Measuring Force | 5–10 N |
| Scale | Satin chrome, ø18 mm |
| Mass | ~315 g |
| Standard | ISO 3611 / DIN 863 |
| Delivered With | Box, 50 mm setting standard, spanner key, inspection certificate |
| Origin | Mitutoyo (Japan) |
🏭 Applications
CNC Turning & Heavy Machining — Verify shaft diameters, flange thicknesses, and coupling dimensions in the 50–75 mm range between machining operations.
Quality Control & Incoming Inspection — Check received castings, forgings, and machined components against drawing tolerances before assembly.
Tool and Die Making — Measure die bores, punch holders, and precision-ground tooling within the 50–75 mm range.
Maintenance and MRO — Check bearing housings, pump shafts, and motor journals during scheduled overhaul and preventive maintenance.
Oil & Gas and Heavy Industry — Inspect valve bodies, pipe fittings, and flange faces to API and ASME dimensional standards.
Why Buy from San Tools?
✅ Authorised Mitutoyo Distributor — Genuine product with full manufacturer warranty.
✅ In Stock in Dubai — Ships same-day from our Al Quoz warehouse.
✅ Calibration Certificates — Traceable certificates for ISO 9001 and IATF 16949 audits.
✅ Free UAE Delivery — On orders over AED 500.
✅ Expert Support — 38 years matching the right instrument to the right application.
Frequently Asked Questions
Is this a genuine Mitutoyo product?
Yes. San Tools is an authorised Mitutoyo distributor in the UAE. Every micrometer ships with Mitutoyo packaging and an inspection certificate.
Does the 103-139-10 come with a setting standard?
Yes. A 50 mm setting standard is included in the box for zero-point calibration. All Mitutoyo micrometers from 25 mm upward ship with a setting standard.
Can I get a calibration certificate?
Yes. We provide traceable calibration certificates on request — essential for ISO 9001, IATF 16949, and AS 9100 quality systems.
How does the 103-139-10 differ from the 103-139?
The "-10" suffix indicates the current production version with updated ratchet mechanism. Specifications and dimensions are identical to the original 103-139.