Description
Product Overview
This Tsugami 47-piece PTW B-4 gauge block set is a Japanese-made slip gauge kit built for toolroom and workshop measurement work — stacking combinations to verify dimensions, setting comparators, calibrating micrometers, and establishing reliable reference lengths on the bench. Housed in its original wooden case, this set covers a practical range of sizes that handles the majority of everyday precision measurement tasks found in a production or jobbing shop environment.
- B-4 Grade Accuracy — B-4 (also referenced as Grade 2 in JIS standards) is a working-grade specification, meaning these blocks are calibrated for general workshop and inspection use rather than laboratory-grade master work. For setting comparators, checking micrometer calibration, or establishing reference dimensions on the bench, working grade is exactly what you need — and keeps cost and risk in proportion to the application.
- 47-Piece PTW Series Configuration — The PTW B-4 build covers the incremental steps needed to wring together virtually any target dimension within range. Having the right number of pieces in a logical series minimises the number of blocks in any given stack, which directly reduces accumulated error — fewer joints means tighter combined uncertainty.
- Hardened Steel Construction — Tsugami gauge blocks are manufactured from hardened alloy steel with lapped and ground reference faces. Hardened steel blocks hold their geometry under repeated use and resist the minor handling wear that would degrade softer materials. The lapped faces allow wringing — the molecular adhesion that locks blocks together without fasteners — which is the foundation of reliable slip gauge work.
- Original Wooden Case Included — The fitted wooden case keeps each block indexed in its correct slot, protecting faces from contact damage during storage and transport. A full case also makes it immediately obvious if a block is missing from the set.
- Ideal For — Setting dial comparators and bench micrometers to a known reference dimension; calibrating and zeroing outside micrometers across their range; establishing precise depth references for surface grinding setups; checking go/no-go gauge wear on the inspection bench; setting toolroom sine bars and sine plates for angular work.
Condition
(Used — Fair Condition / Well-Used Working Set with Modified and Damaged Blocks)
This set has seen genuine workshop service and that needs to be called out clearly before purchase. The majority of blocks remain in serviceable condition — faces are wrингable on most pieces and the blocks function as working-grade references for general bench use. However, a number of blocks have been physically modified during their working life: examples observed include corner chamfers milled into blocks and top faces that have been ground to a radius — modifications made to suit specific clearance requirements in prior applications. These alterations change the geometry of the affected blocks and they should not be relied upon for measurement work without individual inspection and verification against a master. The most significant damage is to the 1 mm block, which is in unusable condition and should be considered absent from the set for practical purposes. Buyers should inspect each block individually upon receipt, discard or quarantine any that do not wring cleanly or show compromised face geometry, and verify remaining blocks against a known master or calibrated reference before committing them to critical measurement work. For setting comparators, rough inspection, or educational use, the serviceable blocks in this set will do the job — just go in with clear eyes about what you’re working with.
Included:
- 1 x Tsugami PTW B-4 47-piece gauge block set (hardened steel, JIS Grade 2 / B-4)
- 1 x Original fitted wooden storage case
Not Included:
- Calibration certificate
- Wringing film or protective accessories
Brand Information
Tsugami is a Tokyo-based Japanese precision engineering company with a long-standing reputation in machine tools and precision measuring equipment. Japanese-manufactured gauge blocks from this era are well regarded in the toolroom trade — sitting in the same quality tier as RSK and alongside Mitutoyo’s working-grade offerings — reflecting Japan’s post-war commitment to tight manufacturing tolerances and consistent material quality in metrology products. While Tsugami is today better known internationally for its CNC sliding-head lathes, their legacy metrology products carry the same hallmarks of Japanese toolroom manufacture: consistent hardening, well-lapped faces, and reliable dimensional control at time of production.
Specifications
| Feature | Specification |
|---|---|
| Brand | Tsugami |
| Model / Series | PTW B-4 |
| Type | Slip / Gauge Block Set |
| Grade | B-4 (JIS Grade 2 — Working / Workshop Grade) |
| Number of Pieces | 47 pieces (1 mm block unusable — effectively 46 serviceable pieces at best) |
| Measurement System | Metric (mm) |
| Material / Construction | Hardened alloy steel, lapped reference faces |
| Reference Temperature | 20°C / 68°F (as marked on case label) |
| Country of Origin | Japan (Tokyo) |
| Case / Packaging | Original fitted wooden storage case included |
| Calibration Certificate | Not included |
| Condition | Used — Fair. Majority of blocks serviceable. Several blocks modified (chamfers milled, faces ground). 1 mm block unusable. |
Keywords
Tsugami gauge block set, Tsugami PTW B-4, slip gauge set metric, 47 piece gauge block set, Japanese gauge blocks, toolroom slip gauges, hardened steel gauge blocks, gauge block set Australia, workshop grade slip gauges, sine bar setup blocks, micrometer calibration blocks, precision measurement toolroom
