Page 321 - Content.pmd

Chart illustrating the standard marking system is :551- 1966 (Table -2)
TABLE 2
ORDER OF MAKING
3 1 2 3 4 5 6
Nature Type of Grain Grade Structre Typr of Manufacture’s
Wheel Abrasive Size bond Reference

51 A 36 L 5 V 23

Manufacture’s Manufacturer’s
symbol indicating own identification
the exact nature of mark for the
Abrasive (optional) wheel(optional)

V - VITRIFIED
S - SILICATE
R - RUBBER
ALUMINIUM OXIDE -A RF - RUBBER REINFORCED
SILICONCABIDES - C B - RESINOID(SYNTHETIC
REINFORCED
BF - RESINOID REINFORCED
E - SHELLAC
Mg - MAGNESIA
- OXY Acetellic

COARSE MEDIUM FINE VERYFINE
10 30 220
12 36 80 240
14 46 280
16 54 100 320
20 60 120 400
24 150 500
180 600
SPACING FROM THE CLOSEST
TO THE MOST OPEN
0 8
1 9
2 10
3 11
4 12
5 13
6 14
7
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

SOFT MEDIUM HARD

CHART ILLUSTRATING STANDARD MARKING SYSTEM 1S : 551 - 1966

300 £_õ & Gm: @©hPo (NSQF - Revised 2022) ------ R.T. for Ex. No.1.5.74-76