Description
Product Overview
The RSK 42mm Plain Setting Ring is a precision ground bore reference standard used to set and verify internal measuring instruments — bore gauges, air gauges, and three-point internal micrometers — to a known diameter before you put them to work on the job. At 42mm nominal diameter, this ring covers a size that comes up constantly in shaft-and-bore fitment work, bearing housing checks, and hydraulic cylinder inspection. It’s a toolroom staple, not a nice-to-have.
- Precision ground internal bore — the working surface that matters. The bore of a setting ring is lapped and ground to extremely tight tolerances, giving your bore gauge a stable, repeatable zero reference. Without a traceable setting ring, you’re zeroing off your own part — and that’s circular logic on the shop floor.
- Hardened steel construction. The ring is manufactured from hardened tool steel, which resists wear on the internal datum surface across years of regular use. A soft ring would drift out of spec every time an instrument was set against it, defeating the purpose entirely.
- Knurled outer diameter for secure handling. The aggressive knurl on the OD gives a positive grip when you’re setting a bore gauge one-handed at the bench — no fumbling, no dropping a precision standard onto the concrete floor.
- Compatibility. Suits any bore gauge, air gauge plug, or three-point internal micrometer with a range covering 42mm nominal diameter. No additional accessories are required to use the ring — it is a self-contained reference standard. A calibration certificate is included, allowing traceability back to a known standard.
- Ideal for: Zeroing bore gauges for bearing housing inspections, setting three-point internal mics for hydraulic cylinder bore checks, verifying bore gauge repeatability before a precision fitting run, and incoming inspection of 42mm nominal bores on turned components.
Condition
Used (Good Condition / Previously Calibrated, Includes Certificate)
The bore — the only surface that does any real work — is in good condition, retaining the ground finish required for accurate instrument setting. The external faces show the honest patina of a used precision tool: light surface oxidation and minor handling marks are visible on the flat faces and OD, consistent with bench use and storage. The unit has been lubricated and plastic-wrapped for storage, which is correct practice for preserving a hardened steel reference standard. There is no visible damage to the bore surface, no scoring, and no corrosion pitting on the internal datum that would compromise its function as a setting reference. The engraved markings — ø42 nominal diameter and the RSK brand stamp with serial number — are legible. As with any used setting ring, independent verification against a calibrated CMM or comparator is recommended before relying on it for tight-tolerance work, particularly if your process demands traceability to NATA-accredited standards. The included calibration certificate provides a documented reference point for that verification.
Included
- 1 x RSK Plain Setting Ring, 42mm Nominal Diameter
- 1 x Calibration Certificate
Not Included
- Storage case (sold without case)
Brand Information
RSK (Rika Seiki Kogyo Co., Ltd.) is a well-regarded Japanese manufacturer of precision measuring instruments and gauge standards, producing setting rings, plug gauges, and associated metrology tooling to Japanese Industrial Standards (JIS). RSK sits in the same respected tier of Japanese toolroom metrology as Mitutoyo and Niigata Seiki — known for consistent manufacturing quality, proper material hardness, and reliable ground tolerances that hold up in production environments. Japanese-made precision standards carry a strong reputation in Australian toolrooms for good reason: the manufacturing discipline that comes out of Japanese metrology factories is well documented, and RSK is a trusted name among toolmakers who specify gauge standards rather than accepting whatever comes in a kit.
Specifications
| Feature | Specification |
|---|---|
| Brand | RSK (Rika Seiki Kogyo Co., Ltd.) |
| Type | Plain Setting Ring Gauge |
| Nominal Diameter | 42mm (ø42) |
| Tolerance Class | Master Grade (表±0 — as marked; verify against certificate) |
| Material / Construction | Hardened tool steel, precision ground and lapped internal bore |
| External Feature | Knurled outer diameter for handling |
| Identification Markings | ø42 nominal diameter, RSK brand stamp, serial number engraved |
| Country of Origin | Japan |
| Condition | Used — Good Condition |
| Included Items | 1 x Setting Ring, 1 x Calibration Certificate |
| Not Included | Storage case |
Keywords
RSK setting ring, RSK 42mm ring gauge, plain setting ring 42mm, bore gauge setting ring, internal bore reference standard, ring gauge toolroom, RSK Japan metrology, bore gauge zero reference, 42mm gauge ring, setting ring calibration certificate, bore gauge accessories Australia, precision ring gauge machinist
