Description
Product Overview
A precision ground setting ring is one of the most fundamental reference standards on the toolroom bench — and this Ocean 28mm Setting Ring (±0 tolerance, model D606) is exactly what you need to zero your Holtest or three-point internal micrometer before you trust it with a critical bore measurement. Without a traceable ground reference like this, you’re guessing. With it, you’re working to spec.
- 28mm nominal bore diameter, ±0 tolerance class — The ±0 marking indicates this ring is ground to the tightest available tolerance band, meaning the bore is held to nominal with virtually no deviation. That matters when you’re setting a Holtest before measuring a bearing housing or hydraulic cylinder bore where even half a thou of error compounds into a reject part.
- Precision ground internal bore with knurled OD — The bore surface is finish-ground to a mirror-smooth reference surface, giving your three-point micrometer anvils a consistent, repeatable seat every time you zero. The knurled outer diameter gives secure grip when handling with oily hands on the bench — a practical detail that matters when you’re mid-setup.
- Hardened steel construction — Setting rings cop a lot of handling wear over their service life. A hardened body resists dimensional creep and surface wear that would compromise your zero reference over time. This one shows typical workshop patina on the outer faces but the bore remains the critical surface, and it presents cleanly.
- Compatibility — Designed specifically for setting Holtest internal micrometers and three-point (tri-anvil) internal micrometers in the 28mm nominal range. No adapters required — simply seat your instrument in the bore, zero it off, and go. Not intended as a thread ring or snap gauge.
- Ideal for — Zeroing Holtest or three-point internal micrometers before measuring bearing bores, hydraulic cylinder liners, bushing housings, valve bodies, and any precision bore inspection where you need a reliable ground reference rather than relying on a worn or estimated zero.
Condition
(Used — Good Condition / Workshop Patina, Bore Surface Intact)
This setting ring is in good used condition and is fully functional as a bore reference standard. The critical surface — the ground internal bore — is clean, smooth, and free from scoring, pitting, or visible wear that would compromise its reference accuracy. The external faces and OD show typical workshop patina and minor surface marks consistent with bench use and storage over time; these are cosmetic only and have zero bearing on the ring’s function as a setting reference. The engraved markings (ø28, ±0, Ocean, D606) are clean and fully legible. As with any used metrology standard, we recommend verifying the bore diameter against a calibrated reference instrument or CMM if your application requires certified traceability. For general toolroom and production floor use, this ring will do exactly what it’s meant to do: give your internal mike a reliable zero before you measure.
Included:
- 1 x Ocean D606 28mm Setting Ring (±0 tolerance)
- 1 x Original green storage/presentation box
Not included: Calibration certificate (not supplied — verify against a calibrated reference if traceability is required).
Brand Information
Ocean is a Japanese precision metrology brand with a solid reputation in the toolroom and production measurement market. Japanese-made gauge standards of this type sit in the same respected tier as Niigata, RSK, and Etalon — manufactured to tight tolerances using hardened and ground steel with consistent quality control typical of Japanese industrial metrology practice. Ocean setting rings are well regarded by toolmakers and production engineers across the Asia-Pacific region as reliable, accurate reference standards that punch above their price point compared to European equivalents.
Specifications
| Feature | Specification |
|---|---|
| Brand | Ocean |
| Model | D606 |
| Type | Plain Setting Ring Gauge |
| Nominal Bore Diameter | 28mm |
| Tolerance Class | ±0 (ground to nominal) |
| Primary Use | Setting / zeroing Holtest and three-point internal micrometers |
| Bore Surface Finish | Precision ground |
| Outer Diameter Feature | Knurled grip |
| Material / Construction | Hardened steel |
| Country of Origin | Japan |
| Condition | Used — Good Condition (cosmetic patina; bore surface intact) |
| Included Items | Setting ring, original storage box |
| Not Included | Calibration certificate |
Keywords
Ocean D606 setting ring, Ocean 28mm ring gauge, plain setting ring 28mm, Holtest setting ring, three point micrometer setting ring, internal micrometer reference gauge, bore gauge zero reference, toolroom ring gauge, precision bore setting standard, 28mm bore gauge, internal micrometer zeroing, Japanese metrology gauge
