Description
Product Overview
The Mitutoyo 329-250 is a 0–300mm digital depth micrometer built for toolroom-grade depth measurement where a vernier depth gauge simply won’t cut it. With a 0.001mm resolution digital readout and interchangeable extension rods, this instrument is designed for machinists who need repeatable, traceable depth readings across a wide range — from shallow step measurements to deep bore and counterbore depths. It’s a serious piece of kit from the world’s benchmark metrology manufacturer, and this example comes complete with its original accessories and documentation.
- 0.001mm (1 micron) resolution digital readout — That extra decimal place over a standard vernier depth gauge matters when you’re holding a shoulder depth to a tight tolerance or verifying counterbore depth for a precision fit. The Absolute encoder (SPC-capable) eliminates the need to re-zero on power-up, so you’re reading actual position the moment you switch it on.
- 0–300mm range via interchangeable extension rods — The modular rod system lets you cover the full 300mm range in increments without swapping instruments. Each rod is ground to a precise length, so stack-up error is minimised as long as the rods are seated correctly and the reference face is clean.
- Hardened and ground reference base — The wide, flat base (beam) is lapped and hardened, giving you a stable ground reference surface that sits flush across a bore face, step, or workpiece edge without rocking. This is the detail that separates a proper depth mic from a cheap imitation — if the base isn’t flat and square to the spindle axis, every reading is suspect.
- SPC data output port — The onboard SPC (Statistical Process Control) output allows direct connection to Mitutoyo’s U-WAVE or a data logger for process documentation, gauge R&R studies, or quality records. Relevant if you’re working to ISO 9001 or AS/NZS quality requirements.
- Ideal for — verifying counterbore and countersink depths to engineering drawing call-outs, checking keyway depths on shafts and hubs, measuring shoulder depths on turned components, confirming step depths on milled pockets and slots, and measuring bore depths on castings or housings during fitting work.
Condition
Used (Good Condition / Workshop Used, Fully Functional)
This Mitutoyo 329-250 presents as a genuine workshop tool that has seen use — exactly what you’d expect from a quality instrument that’s been earning its keep on a bench. The digital display is clear and responsive, the thimble rotates smoothly with no perceptible play, and the locking mechanism holds position correctly. The reference base shows the kind of light patina and minor handling marks consistent with careful use in a professional environment; there are no deep gouges, chips to the measuring surfaces, or damage to the spindle face or anvil that would compromise the accuracy of a measurement. The extension rods are present, wrapped in their original protective paper and some unopened, and show no signs of impact damage or corrosion on the ground measuring faces. The original Mitutoyo case, papers, and calibration certificate are included — a meaningful detail for any shop that needs traceable documentation. As with any pre-owned precision instrument, we recommend verifying zero against a known reference surface before putting it to work. A quick zero check on a surface plate or a ground parallel will confirm the instrument is reading correctly before it goes into service.
Included
- 1 x Mitutoyo 329-250 Digital Depth Micrometer, 0–300mm, 0.001mm resolution
- Interchangeable extension rods (full set for 0–300mm range, original accessories)
- Original Mitutoyo fitted case
- Original papers / manual
- Calibration certificate
Not Included
- SPC data cable (sold separately by Mitutoyo — standard item if data output is required)
Brand Information
Mitutoyo Corporation, founded in Japan in 1934, is the global benchmark in dimensional metrology — the name machinists and metrologists reach for when accuracy is non-negotiable. Their instruments are manufactured to tolerances that set the standard other brands are measured against, with a global calibration and service network that makes traceability straightforward. In the metrology market, Mitutoyo sits at the top tier alongside Mahr and Starrett, and is the default specification on most toolroom and quality lab purchasing lists in Australia and worldwide.
Specifications
| Feature | Specification |
|---|---|
| Brand | Mitutoyo |
| Model | 329-250 |
| Type | Digital Depth Micrometer |
| Series | 329 Series (Digimatic Depth Micrometer) |
| Measuring Range | 0–300mm (via interchangeable extension rods) |
| Resolution | 0.001mm (1 micron) |
| Accuracy | ±4µm (refer to Mitutoyo documentation for full tolerance breakdown by range) |
| Display | LCD digital readout with mm/inch switchover |
| Encoder Type | Absolute encoder (no re-zero required on power-up) |
| Data Output | SPC output port (compatible with Mitutoyo U-WAVE and data loggers) |
| Base / Beam Width | 101.6mm hardened and ground reference base |
| Construction | Hardened stainless steel measuring faces; ground and lapped reference base |
| Country of Origin | Japan |
| Condition | Used (Good Condition / Workshop Used, Fully Functional) |
| Included Items | Instrument, full extension rod set, original case, papers/manual, calibration certificate |
| Not Included | SPC data cable, setting standard/reference bar |
Keywords
Mitutoyo 329-250, Mitutoyo digital depth micrometer, depth micrometer 0-300mm, Mitutoyo digimatic depth micrometer, digital depth mic 300mm, interchangeable rod depth micrometer, toolroom depth micrometer, depth micrometer SPC output, counterbore depth measurement, precision depth gauge Australia, Mitutoyo 329 series, bore depth measurement tool
