Angles and flatness

V-blockV-block (Vee block)

Also called: Vee block

≡Standards, measuring range and accuracy

Standard

JIS B 7540:1972 V-blocks^[1]1 source, for reference

Measuring range

byMaker
- Obishi Keiki hardened steel precision V-block Nominal 38 (applicable diameter 4–25 mm) to 250 (7–205 mm)

^[2]1 source, for reference

Resolution / graduation

—Not confirmed in public sources

Accuracy (instrument error / maximum permissible error)

byMaker
- Obishi Keiki JA101/JA201 (nominal 38) Parallelism of base to V-groove: grade AA 3 µm, grade A 5 µm

^[2]1 source, for reference

▦Types

Precision hardened steel (pair of 2, hardened, 90° V-groove), carbide-tipped, with clamp, cast iron (type A, type B, with fittings), stone, box-type block with V-groove

^[2][3]1 source, for reference

◎Part names and functions

#	Name	English	Function
1	V-groove / base / side faces	Vee groove, base, sides	Sold as a pair of 2, with the parallelism of base and V-groove matched.^[2]

✋Usage steps

Used for inspecting round workpieces and as an auxiliary block (shojikidai)^[2]
Before use, clean the working surface and the workpiece and let them settle to the same temperature. Remove light scratches locally with an Arkansas stone, etc.^[2]

Printed from Kezuriba (kezuriba.net/en/gauges/v-block/)

!Common measurement mistakes and countermeasures

Dropping or impact

Why

CountermeasureCheck for abnormalities before use^[2]

✓Care, storage, inspection and calibration

Care and storage

After use, rust-proof and store in a storage box^[2]

Inspection and calibration

Check accuracy periodically^[2]

⇄Related instruments

Surface plate Lever-type dial indicator (dial test indicator)Height gauge

📚Sources

Content without a mark is what agreed across two or more sources from different publishers. Procedures and cautions are summarized in Kezuriba's own words based on the sources, and the diagrams were drawn by Kezuriba. Accuracy values are manufacturers' published figures, not values from JIS tables.