Description
Product Overview
When you’re marking out compound angles on the mill, setting a sine bar, or trying to verify a chamfer that the drawing calls at 37°30′, eyeballing it with a combination square isn’t going to cut it. You need a proper bevel protractor with a vernier or micrometer read-out that lets you resolve minutes of arc — not degrees alone. The Marui Keiki Micro Protractor is exactly that instrument: a precision optical-style dial protractor with a fine-adjust thimble mechanism that gives you repeatable angular readings to a resolution that makes short work of compound angle setups, dovetail verification, and taper checks on the bench. This is a well-used set that’s still working and accurate — honest shop patina, genuine capability.
- Micrometer-head fine adjustment — the knurled thimble allows fine angular setting without locking and re-locking the blade, which is exactly what you want when sneaking up on a tight tolerance angle during layout or inspection.
- Large graduated dial face — the circular dial with clearly engraved degree markings gives a stable, parallax-friendly read from any bench position; far easier to read under workshop light than a standard bevel protractor vernier scale.
- Swivel blade with through-holes — the hardened blade can be repositioned and clamped, making it practical for both internal and external angle measurement and for referencing against a machined surface directly.
- Square reference attachment included — the small square attachment in the case gives you a fixed 90° reference blade, expanding the tool’s use to squareness checks and step measurements without needing a separate engineer’s square.
- Ideal for — verifying compound angles on milled parts, setting the compound slide on a lathe, checking dovetail angles, confirming chamfer and bevel specifications on fabricated components, and angular layout work on the surface plate.
Condition
Used (Fair Condition / Functional with cosmetic wear and minor glass chip)
Mechanically, this protractor is doing its job — the dial rotates smoothly, the thimble fine-adjust engages without slop, and the blade clamp locks positively. The graduated surfaces show the kind of patina you’d expect from a tool that’s been on a working bench rather than sitting in a cabinet: some surface wear and handling marks consistent with regular use. The most notable flaw is chipping to the glass lens at the bottom edge — visible in the image and confirmed by the seller. The chip is cosmetic in nature and sits outside the active graduated arc of the dial face; it does not obscure the degree markings or the index line in normal use. The blade and square attachment are present and intact. As with any used angular instrument, it’s worth verifying the zero against a known ground reference surface or a precision angle block before putting it to work — standard practice for any second-hand protractor coming back into service.
Included:
- 1 x Marui Keiki Micro Protractor (dial-type bevel protractor with micrometer fine adjust)
- 1 x Swivel measurement blade
- 1 x Square reference attachment
- 1 x Original timber storage case with foam insert
Not included: No certificate of calibration. No additional blade extensions observed in the case.
Brand Information
Marui Keiki (丸井計器) is a Japanese precision instrument manufacturer with a history in metrology tooling for the industrial and toolroom market. Japanese-made measuring instruments from this era are well regarded for their ground reference surfaces, quality optical glass, and consistent mechanical feel — sitting in the same general tier as other mid-to-upper Japanese metrology names recognised on Australian shop floors. While Marui Keiki does not carry the same global name recognition as Mitutoyo or Mahr, their instruments were built to genuine toolroom standards and were specified by serious manufacturers, not the hobby end of the market.
Specifications
| Feature | Specification |
|---|---|
| Brand | Marui Keiki (丸井計器) |
| Model | Micro Protractor |
| Type | Dial / Micrometer Bevel Protractor |
| Measuring Range | 0–360° (full circle dial graduation) |
| Fine Adjust | Micrometer thimble mechanism |
| Dial Face | Circular graduated dial with glass lens cover |
| Blade | Hardened swivel blade with through-holes, lockable |
| Accessories Included | Square reference attachment, measurement blade |
| Country of Origin | Japan |
| Condition | Used (Fair) — functional, cosmetic wear, glass chip at lower lens edge |
| Case | Original timber case with foam insert (included) |
| Not Included | Calibration certificate; no additional blade extensions observed |
Keywords
Marui Keiki micro protractor, Marui Keiki bevel protractor, dial protractor Japan, precision bevel protractor Australia, micrometer protractor toolroom, angular measurement machinist, compound angle layout tool, bevel protractor used, Japanese metrology instrument, precision protractor surface plate, angle measurement milling, toolroom protractor second hand
