Description
Product Overview
The Mitutoyo 468-981 Digital Holtest is a three-point internal micrometer covering the 6–12mm range — the go-to tool when you need bore measurement accuracy that a two-point bore gauge simply can’t match. Designed for measuring small-to-mid bores in a single self-centring contact, the Holtest eliminates the rocking technique required with two-jaw bore gauges and reads directly in microns on a clear digital display. Whether you’re checking reamed holes, small hydraulic bores, bearing housings, or drilled and honed cylinders, this instrument belongs on the bench of anyone doing serious hole-tolerance work.
- Three-point self-centring contact system — Unlike a two-anvil bore gauge that requires careful rocking to find true diameter, the three equally-spaced carbide-tipped contacts automatically centre the instrument in the bore. This means repeatable, operator-independent readings, which matters enormously when you’re chasing H7 or tighter fits and can’t afford measurement scatter between operators or setups.
- Digital readout with 0.001mm (1 micron) resolution — The LCD display gives you instant, unambiguous readings without interpolating a vernier or analogue dial. Zero/origin function lets you set the instrument to a master ring and read deviation directly — fast and clean on the production floor or in the toolroom.
- IP65-rated dust and coolant resistance — Visible on the instrument bodies in the photograph, the IP65 rating means splash coolant, cutting fluid, and airborne swarf won’t compromise the electronics or the measuring system. This is a practical toolroom and machine-side instrument, not a lab-only piece.
- Carbide-tipped measuring contacts — Hardened carbide contact faces resist wear from repetitive bore measurement across cast iron, steel, and hardened materials. Over thousands of measurements, contact wear is the primary accuracy killer on internal micrometers — carbide tips dramatically extend the reliable service life of the instrument.
- Ideal for — Checking reamed and bored holes to print tolerance, verifying bearing housing bores before press-fit, inspecting small hydraulic and pneumatic cylinder bores, checking drilled and honed holes on production runs, and measuring bushing and sleeve IDs during fitting and assembly work.
Condition
(New — Factory Sealed)
This Holtest set is factory sealed and has not been used or calibrated by any third party. All three micrometer heads remain wrapped in their original protective film and packaging as seen in the photograph — the instruments show no contact wear, no rounding on the thimble knurling, and no marks on the measuring faces or spindle threads. The wooden storage case is clean and undamaged, with all foam cutouts holding components firmly in place. A factory calibration certificate is included, traceable to national measurement standards, confirming the set shipped within Mitutoyo’s stated accuracy specification. Setting rings are included as per factory kit configuration, allowing immediate verification and use straight out of the box without sourcing external reference standards. No workshop use, no zeroing wear, no exposure to coolant or swarf. This is as close to purchasing direct from the Mitutoyo distributor as the used and surplus market offers. We recommend zeroing each head against the supplied setting ring before first use as a matter of good metrology practice — not because there is any reason to doubt accuracy, but because it’s the correct protocol before putting any measuring instrument into production.
Included
- 3 x Mitutoyo Holtest Digital 3-Point Internal Micrometer heads — 468-981 series, 6–12mm range
- 3x SR44 Batteries
- 2x Setting rings (as per factory kit — visible in case)
- Wooden storage case
- Original papers / manuals
- Factory calibration certificate
- Original accessories as packed by Mitutoyo
Not Included
- Additional range extensions beyond those supplied in the factory kit
Brand Information
Mitutoyo Corporation, founded in Japan in 1934, is the world’s largest manufacturer of precision measuring instruments and is widely regarded as the benchmark brand in dimensional metrology — sitting at the top of the market alongside Mahr, Tesa, and Starrett, and a clear step above generic Asian OEM instruments. Mitutoyo instruments are manufactured in Japan under rigorous quality control and are the calibration reference of choice in ISO-certified toolrooms, aerospace, automotive, and defence manufacturing facilities worldwide. In the Australian trade, Mitutoyo is the instrument a machinist or toolmaker specifies when accuracy and long-term reliability are non-negotiable.
Specifications
| Feature | Specification |
|---|---|
| Brand | Mitutoyo |
| Model / Series | 468-981 / Holtest Series 468 |
| Type | Digital 3-Point Internal Micrometer (Holtest) |
| Measuring Range | 6–12mm (supplied as a set covering this range across multiple heads) |
| Resolution | 0.001mm (1 micron) |
| Accuracy | ±0.003mm (refer to calibration certificate and Mitutoyo datasheet for full tolerance by sub-range) |
| Display | LCD digital readout |
| IP Rating | IP65 — coolant and dust resistant |
| Measuring Contacts | Three-point, carbide-tipped, self-centring |
| Functions | Zero/origin, mm/inch switchable (confirm on unit — standard for series) |
| Country of Origin | Japan |
| Condition | New (Factory Sealed) |
| Included Items | 3 x Holtest heads, setting rings, extension rod, wooden case, manual, calibration certificate, batteries |
Keywords
Mitutoyo 468-981, Mitutoyo Holtest digital, Mitutoyo 3-point internal micrometer, bore mic 6–12mm, digital holtest set, three point bore micrometer, internal micrometer set, toolroom bore gauge, small bore micrometer, Mitutoyo digital bore gauge, bore measurement machining, precision internal micrometer Australia
