Engineering VEE Blocks

 V blocks

. the constructional features of 'v' blocks

. the types of 'v' blocks and state their uses

Constructional features

'V' Blocks are devices used for marking and setting up work on machines.The features of the common 'v' blocks.

The included angle of the VEE is 90° in all cases.'V' blocks are finished to a  high accuracy in respect of dimension flatness and squareness.

Types

Different types of 'V' blocks are available. As per BIS there are four type.

Single level single groove 'V' Block

This type has only one 'V' groove, and has single groove (slots) on their side. These grooves are for accommodating the holding clamps.

Single level double groove 'V' Block

This type will have one 'V' groove l, and two grooves (slot) on either side for clamping in two positions.

Double level single groove 'V' Block

In this case, the 'V' block will have two 'V' grooves on the top and bottom, and a single groove for clamping on either side.

Matched pair 'V' Block

These blocks are available in pair which have the same size and the same grade of accuracy. They are identified by the number or letter given by the manufacturer. These sets of blocks are used for supporting long shafts, parallel on machine tables or marking off tables.

Grades and materials

V blocks are available in Grade A and Grade B.

Grade A 'V' Blocks

There are more accurate, and are available only up too 100 mm length. There are made high quality steel.

Grade B 'V' Blocks

These blocks are not as accurate as the ones in Grade A. These blocks are used for general machine shop work. These blocks are available up to 300mm length. These 'V' Blocks are made of closely grained cast iron.

Clamping devices for 'V' Blocks

'U' clamps are provided for holding cylindrical jobs family on 'V' Blocks.

Designation

'V' blocks are designated by the nominal size (length ) and the minimum and maximum diameter of the workpiece capable of being clamped, and the grade and the number of the corresponding B.I.S standard.

In the case of matched pairs, it should be indicated as,'WITH CLAMPS'

Example

A 50mm long (normal size)'V' block capable of clamping workpiece between 5 to 40mm in diameter and of grade A will be designated as

'V' block 50/5-40 A-I. S. 2949

In the case of matched pair, it will be designated as 'V' block

M50/5-40 A I. S.2949

For 'V' block supplied with clamps, the designation will be 'V' block with clamp    50/5 40 A I. S. 2949.