Description
Product Overview
The SK 2.50–3.00mm Gauge Pin Set (Class AA-2B) is a high-precision cylindrical pin gauge set covering the 2.50mm to 3.00mm range in 0.01mm increments — giving you 51 individual pins to verify bores, ream clearances, and slot widths with toolroom-grade confidence. Made in Japan by Shinwa Sokutei (SK), these pins are ground and lapped to exacting tolerances, making them the go-to reference standard for quality control, incoming inspection, and setup verification on the bench or at the machine.
- Class AA-2B Tolerance Grade — Ground to sub-micron accuracy: The AA classification means these pins are held to the tightest commercially available tolerance, typically within ±0.001mm or better depending on the specific pin diameter. That matters because a pin set is only as useful as it is accurate — a mid-grade pin introduces its own error into your measurement, defeating the purpose of using a reference standard in the first place.
- 0.01mm increments across the full 2.50–3.00mm range: With 51 steps from 2.50mm to 3.00mm, you have the resolution to identify whether a bore or slot is on tolerance, over, or under — not just ballpark it. For reaming operations, this allows you to confirm the finished bore to the nearest hundredth before the part goes downstream.
- Hardened and lapped pin surfaces: The gauge pins are manufactured from hardened tool steel with a precision-lapped cylindrical surface. This gives you a reliable, wear-resistant reference that will hold its size through repeated use without the surface degrading the way a softer standard would.
- Knurled handle bodies for single-hand use: Each pin is mounted in a knurled plastic or anodised handle — visible in the image — allowing one-handed insertion while you hold the part or gauge with the other. This is a practical detail that matters when you’re checking a batch of parts at the inspection bench.
- Ideal for: Verifying reamed bore diameters on turned or milled components, checking punch and die clearances, qualifying drill jig bushings, inspecting slot widths on milled parts, setting dial bore gauges against a known reference, and incoming inspection of precision-ground components.
Condition
Used (Good Condition / Mostly Unwrapped, Near-New Pins)
The vast majority of pins in this set remain in near-new condition — the seller confirms only several pins have been unwrapped and used, with the remainder still in original wrapping. The pin surfaces and ground cylindrical forms on the used pins show no visible scoring, pitting, or wear that would compromise their dimensional accuracy. The original wooden storage case shows honest signs of age — wear to the exterior finish and some cosmetic patina consistent with workshop storage — but the foam insert and pin holder tray are intact, all 51 pin positions are occupied, and no pins are missing. The calibration certificate is included, tucked inside the case, which gives you documented traceability at the time of last calibration. As with any used gauge pin set, best practice is to verify the pins you intend to use against a calibrated ring gauge or optical comparator before committing them to a critical inspection task, particularly if the calibration certificate date is outside your facility’s acceptable recalibration interval. For general shop use, setup verification, and bore gauging, this set represents excellent value in a condition well above what you’d expect from a used precision standard.
Included:
- 1 x SK Gauge Pin Set, 2.50–3.00mm, Class AA-2B, 51 pins (0.01mm increments), complete — no missing pins
- 1 x Original wooden storage case with foam lid insert and moulded pin holder tray
- 1 x Calibration certificate (stored inside the case)
Not included:
- No additional accessories required — set is self-contained
- Recalibration service not included — buyer to assess currency of calibration certificate against their own quality requirements
Brand Information
SK is the tooling and metrology brand of Shinwa Sokutei Co., Ltd., a Japanese precision instrument manufacturer with decades of production history supplying toolroom-grade measuring equipment to the Japanese domestic and export markets. SK instruments are manufactured in Japan to JIS standards and sit comfortably alongside Mitutoyo and RSK in terms of build quality, material specification, and accuracy grade — they are a legitimate Japanese precision brand, not a rebadged import. In the Australian and broader Asia-Pacific market, SK gauge pins and measuring tools are well regarded by toolmakers and quality engineers who need Japanese-grade accuracy without paying Mitutoyo catalogue pricing.
Specifications
| Feature | Specification |
|---|---|
| Brand | SK (Shinwa Sokutei Co., Ltd.) |
| Product Name | Gauge Pin Set |
| Series / Grade | AA-2B (Class AA — highest commercial tolerance grade) |
| Measuring Range | 2.50mm – 3.00mm |
| Increment / Resolution | 0.01mm (10 micron steps) |
| Number of Pins | 51 pins (complete, no missing pins) |
| Accuracy Grade | Class AA — tolerance typically within ±0.001mm (verify against current JIS B 7420 specification for exact per-diameter tolerance) |
| Pin Material / Construction | Hardened tool steel, precision ground and lapped cylindrical surface |
| Handle Style | Knurled handle body (facilitates single-hand insertion) |
| Country of Origin | Japan |
| Storage | Original wooden case with foam lid and moulded pin tray |
| Condition | Used (Good Condition) — mostly near-new pins, only several unwrapped; case shows age-related wear |
| Included Items | Full 51-pin set, original wooden case, calibration certificate |
| Not Included | Recalibration service |
Keywords
SK gauge pin set, SK AA-2B pin gauges, SK Shinwa Sokutei gauge pins, gauge pin set 2.50–3.00mm, cylindrical pin gauge set Australia, pin gauge bore inspection, toolroom gauge pins, precision pin gauges Japan, bore gauge reference pins, go no-go pin gauge, inspection pin set machinist, gauge pin set with calibration certificate
