Description
Mitutoyo 35–40mm H4 Holtest — Internal Micrometer
The Mitutoyo Holtest is the benchmark internal micrometer for toolroom and production floor alike. This 35–40mm H4 unit gives you direct, two-point bore measurement with micrometer-grade accuracy — far more repeatable than a three-point telescoping gauge and infinitely faster to read than a bore gauge needing a reference standard at every session. If you’re chasing tight fits on bearing housings, hydraulic cylinder bores, or checking finish-bored holes to drawing tolerance, this is the instrument that earns its place on the bench.
- Two-point micrometer contact system — Unlike three-point Holtest variants, the H4 series uses a traditional opposed-anvil geometry. This means it reads on a true diameter line, which is critical when you need to detect out-of-round or lobing in a bore rather than just average diameter. Paired with a consistent feel from the ratchet-stop thimble, operator-to-operator repeatability is tight.
- 35–40mm measuring range in a single head — The 5mm span covers a practical sweet spot for bearing bores, bushing fits, and spindle housings. No extension rods or interchangeable contacts needed within range — just set, insert, and read. Fewer moving joints means fewer sources of error.
- Mitutoyo ground and lapped measuring faces — The anvil faces are hardened and precision-ground to Mitutoyo’s published accuracy spec. On a used instrument in good mechanical condition this matters because the contact geometry is what makes the measurement — a worn or pitted face introduces cosine error that accumulates quietly and ruins a fit.
- Setting ring required for zeroing — A Holtest cannot self-zero against a flat reference. A dedicated setting ring (typically 37.5mm or at your target nominal) is required to establish datum before use. If you don’t already have one, budget for it — Mitutoyo and aftermarket rings are available in AU. This instrument ships without a setting ring.
- Ideal for — Checking finish-bored and reamed holes to tolerance, verifying bearing housing bores prior to press-fit, measuring bushing IDs, confirming hydraulic cylinder liner diameters, and production inspection of turned or bored components where a bore gauge would require a separate dial indicator setup.
Condition
Used (Good Condition / Mechanically Sound, Normal Workshop Patina)
The thimble rotates smoothly through the full range with no stiction, backlash, or tight spots — the spindle advances and retracts cleanly, and the ratchet-stop functions correctly to deliver consistent measuring force. The measuring faces show no visible pitting, scoring, or chipping that would compromise contact geometry. The locking lever operates positively. Cosmetically, the instrument carries the expected patina of a used toolroom piece — minor handling marks and light surface wear on the body — nothing that affects function or metrology. The engraved graduations on the thimble and barrel are clean and legible. As with any pre-owned precision instrument, we recommend zeroing this Holtest against a certified setting ring at your target nominal before committing it to production work. A quick check against a ring gauge or calibrated master bore will confirm it’s reading within spec and give you full confidence before it goes on the floor.
Included:
- 1 x Mitutoyo H4 Holtest Internal Micrometer, 35–40mm
- 1 x Original Mitutoyo wooden storage case
- 1 x Original papers / documentation
Not included: Setting ring (required for zeroing — not supplied), spanner wrench.
Brand Information
Mitutoyo Corporation, founded in Japan in 1934, is the world’s largest manufacturer of precision measuring instruments and the global reference standard in dimensional metrology. Mitutoyo product sits at the top tier of the market alongside Mahr, Tesa, and Starrett — instruments specced into aerospace, automotive, and defence manufacturing where measurement uncertainty is non-negotiable. In Australian toolrooms and machine shops, Mitutoyo is the most recognised and trusted metrology brand on the bench, with local support, calibration services, and ready availability of accessories including setting rings and replacement contacts.
Specifications
| Feature | Specification |
|---|---|
| Brand | Mitutoyo |
| Model / Series | Holtest H4 |
| Type | Two-point internal micrometer (Holtest) |
| Measuring Range | 35–40mm |
| Graduation / Resolution | 0.001mm (1 micron) |
| Accuracy | ±0.003mm (per Mitutoyo H4 series specification — verify against current Mitutoyo catalogue) |
| Contact System | Two-point opposed anvil |
| Measuring Force | Controlled via ratchet-stop thimble |
| Material / Construction | Hardened steel measuring faces; precision-ground anvils |
| Zeroing Method | Setting ring (not included) |
| Country of Origin | Japan |
| Condition | Used — Good Condition / Mechanically Sound |
| Included Items | Instrument, original wooden case, original papers |
| Not Included | Setting ring, spanner wrench |
Keywords
Mitutoyo Holtest H4, Mitutoyo internal micrometer, Holtest 35-40mm, bore micrometer 35mm, internal micrometer toolroom, Mitutoyo bore mic, two-point internal micrometer, precision bore measurement, bearing housing micrometer, machinist internal gauge, metrology Australia, Mitutoyo used micrometer
