Product Overview

Checking squareness on machine columns, fixture plates, or weldments demands a reference square you can actually trust — one that’s traceable to a recognised standard rather than “near enough.” The Obishi Keiki 300mm Precision Square is a JIS Grade 1 cylindrical/beam square built for exactly this work: verifying perpendicularity on surface plates, setting up vertical mills, tramming columns, and inspecting finished components where squareness tolerances are tight. With this one still in new-old-stock condition — wax paper intact, certificate in the box — you’re essentially buying a zero-hour reference tool at a fraction of current retail.

JIS B7526 Grade 1 accuracy — the top certification tier for Japanese precision squares, suitable for inspection room and metrology use.
300mm nominal size covers the sweet spot for machine tool tramming, surface plate work, and medium-sized fabrication checks.
Hardened, ground and lapped reference faces for stable, repeatable blade-to-base perpendicularity.
Ideal for milling machine column checks, lathe tailstock alignment verification, surface plate squareness testing, toolroom inspection, and QC departments.
Comes with original JIS inspection certificate — critical for ISO-compliant workshops and anyone needing documented traceability.

Condition

New Old Stock (Unused / Factory Fresh).

This square has never been put into service. It’s been sitting in its original fitted timber case in dry storage, still largely wrapped in the factory anti-rust wax paper that Obishi Keiki applies before packing. The paper was only peeled back briefly for photography and to verify the certificate matches the tool — then re-covered. No handling marks on the reference faces, no corrosion, no dings, no evidence of drops or mishandling. The wax film is intact across the ground surfaces, meaning the precision finish is exactly as it left the Niigata factory. Once you’re ready to use it, wipe the wax off with a lint-free cloth and a light solvent, and it’s ready for the surface plate. For a tool of this calibre, finding NOS examples with the original certificate still intact is genuinely uncommon.

Included:

1 x Obishi Keiki 300mm Precision Square (JIS Grade 1)
Original fitted timber storage case
Original JIS inspection certificate
Factory anti-rust wax paper wrapping

Brand Information

Obishi Keiki Seisakusho, based in Niigata, Japan, is one of the country’s most respected makers of precision reference standards — squares, levels, straight edges, surface plates, and V-blocks used across Japanese industry for machine tool geometry and inspection work. Their products carry the JIS mark, the Japanese Industrial Standard certification recognised globally alongside DIN and BS, and sit in the same professional tier as Mitutoyo and RSK. A squares-and-levels maker of this pedigree means the tool in your hand is one you’ll verify against, not second-guess.

Specifications

Feature	Specification
Brand	Obishi Keiki Seisakusho
Type	Precision Machinist Square
Standard	JIS B7526 Grade 1
Nominal Size	300mm
Accuracy Class	Grade 1 (Inspection / Metrology Grade)
Material	Hardened tool steel, ground and lapped faces
Country of Origin	Japan
Condition	New Old Stock — Unused
Included	Square, fitted timber case, JIS inspection certificate, factory wax paper

Keywords

Obishi Keiki precision square, Obishi Keiki 300mm square, JIS Grade 1 square, Japanese machinist square, precision engineers square, toolroom square, inspection square, metrology square, machine tool square, NOS precision square, surface plate square, cylindrical square

Obishi Keiki

Obishi Keiki 300mm Precision Square JIS 1

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