Machinery's Handbook, 31st Edition
V-Block Types 741 Type IV, Combination Top and End V-Groove Block.— The Type IV, Combination Top and End V-Groove Block shall be furnished in individual blocks consisting of one block, one clamp and one securing screw which is similar to the design illustrated in Fig. 10. The V-block shall be so designed that when turned on side or end that there shall be no interference from the sliding clamp. One end of the block shall be stepped and this end shall contain a V-groove and clamping grooves at right angle to the base. The blocks shall be designed to facilitate clamping to a machine bed or plate and have two tapped holes in the base and one on each side for mounting purposes. Style 1, Single Level Clamping.— The Type IV, Style 1 Block shall be similar in design to the one shown in Fig. 10 and shall conform to the dimensions and tolerances as defined in Table 9 . The Type IV, Style 1 shall be offered in Grade A configuration. Grade A tolerance shall be applied to the perpendicular secondary V-groove as it is to the primary V-groove. Table 9. Combination Top and End V-Groove Block
Permitted Deviations (inch)
Parallelism of “V” to Base and Side 0.0003
Flatness of Working Faces
End/Side Square to Base
Parallelism of Opposite Faces
Grade
“V” Centrality
Matching Tolerance
Grade A 0.0001
0.0002
0.0002
0.0003
N/A
• Steel alloy • Surface finish NTE 32 µ in • Material hardness 50–62 RC
Characteristics
Nominal Dimensions (inch)
Designating Size
Maximum Capacity
Length 3.625
Width 1.875
Height 1.875
1
1.3125
All dimensions in inches Metric Products.— Products manufactured to metric dimensions (SI units) shall be con sidered on an equal basis with those manufactured to the inch units, providing they fall within the applicable tolerance conversions. The British Standard BS 3731:1987 provides specific requirements for hollow or solid, single or double V-groove blocks made from cast iron or steel, and solid V-blocks made from granite. Two grades of accuracy are de- fined, Grade 1 and Grade 2. Provisions are made for matched sets as well. British Standard V-Block Designs, BS 3731 Maximum Diameter Maximum Diameter Maximum Diameter
B
B
B
Lightning Holes
Max. Dia.
A
A
A Double V-Block a
Cast Iron Hollow V-Block a
Solid V-Block a
a Length C (side view) not shown.
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