8/9/2019 Is 2473-1975 - Norma Furos de Centro
1/8
Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to
information for citizens to secure access to information under the control of public authorities,in order to promote transparency and accountability in the working of every public authority,
and whereas the attached publication of the Bureau of Indian Standards is of particular interest
to the public, particularly disadvantaged communities and those engaged in the pursuit of
education and knowledge, the attached public safety standard is made available to promote the
timely dissemination of this information in an accurate manner to the public.
!"#$% '(%)
!"# $ %& #' (")* &" +#,-.Satyanarayan Gangaram Pitroda
Invent a New India Using Knowledge
/0)"1 &2 324 #' 5 *)6Jawaharlal Nehru
Step Out From the Old to the New
7"#1&"8+9&"), 7:1&"8+9&")Mazdoor Kisan Shakti Sangathan
The Right to Information, The Right to Live
!"# %& ;
8/9/2019 Is 2473-1975 - Norma Furos de Centro
2/8
8/9/2019 Is 2473-1975 - Norma Furos de Centro
3/8
8/9/2019 Is 2473-1975 - Norma Furos de Centro
4/8
:389-W
Fourth Reprint NOVEMBER 1991
( IncorPoratina
4s : 2413 -
mendment
r z
o.
1
1 (R-=-d
19781
Indan Sandard
DIMENSIONS FOR CENTRE HOLES
Frst Revision
Scope - Prescribes dimensions for the,following three types of centre holes:
Type A - Centre holes without protecting chamfers
Type I3 - Centre holes with protecting chamfers
Type R - Centre holes with radius form
Dimensions
l Cenfre Holes
Without Protecting Chamfers Type A
I-4
i-a-4
Ail dimensions in miiiimetres.
at
Nominal
Nominal
Refetence
_
(05)
I
106
10
I
2
I
063 )
132 I2
2
-__-
____
I70
I5
25
1 0
212
I
I9
I
3
t
125
)
265
23
I6
335
29
~-
20
425
)__ X7
2.5
530
46
3 15
670
I
59
9
_~ --_-- --
_/
4.0 850
74 11
( 50 1 1060
9.2 14
83 1320 II5 18
( 80 1 1700
14.8 22
_ _-.
100
2120
184
28
Note -
Sizes given within brackets are non-preferred and shall be avoided whenever possible.
*Dimensioin 1 depends upon length I of the centre drill according
to
IS : 6708-1972 Specification for &Me drills,
Type A .
it shall not, even in the case of drilling with re-sharpened centre drills, be less than the reference value f given
in the table to ensure that the point of the centre does not touch the bot tom of the centre hole.
tparting off dimension, if the centre hole is to be removedfrom the finished workpiece.
I
Adopted 27 November 1975
I
Q
July 1932, BIS
I
Gr2
BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 1 oo02
( Reaffirmed 2002 )
8/9/2019 Is 2473-1975 - Norma Furos de Centro
5/8
IS : 2473 191s
2.2 Centre HoIes With Protecting Chamfers Type B
All dimensions in millimetres.
NoL
1'0
(1.25)
16
20
95
315
40
( 50 1
63
(80)
100
__
-.
__
.-
._
-
-
NOIL
Refefence
at
315
22
35
4
27
45
5 36 56
53
43
66
8
54
83
10 63 100
125 86 127
18 108 156
13
12.9
-
164
__-
204
200
224
250
28
310
-
Noto-Sizes given within brackets are non-preferred and shall be avoided whenever possible.
*Dimension L depends u
It shall not, even
P
on length I of the centre drill according to IS : 6709-1972 Specification for centre drills,
Type B .
nthe case of drllllng with re-sharpened centre dri lls, be less than the reference value t given
In the table to ensure that the point of the centre does not touch the bottom of the centre hole.
tParting off dimension, If the centre hole is to be removed from the finished workpiece.
2
8/9/2019 Is 2473-1975 - Norma Furos de Centro
6/8
.
IS : 2473 1975
Centre Holes With Radius Form, Typ e R
All dimensions in millimetres.
No:lnal
I
D
Nominal
10 212
125 ) 265
16 335
-
20 425
2.5
53
315 87
40 66
( 50 1
106
3
I
132
(VO)
170
100
-1
212
.
_
_.
_
.-
Refetence
19
23
2.9
37
46
58
74
92
114
147
183
r
Max
yin
915
I
15
--_.-_ ---
40
315
50 40
63
50
80
65
100
/
80
I
125
100
180
125
200
160
25.0
200
315 250
d
8
I
4
I
5
I
6
7
9
11
14
18
22
28
Note -
Sizes
given within brackets are non-preferred and shall be avoided whenever possible.
*Dimension L depends upon length I of the centre drill according to IS : 8710-1972 Specification for centre drills,
Type D .
It shall not, even in the case of drilling with m-sharpened centre drills, be less than the referencevalue t given
in the table to ensure that the point of the centre does not touch the bottom of the centre hole.
I
TParting off dimension;if.the centre hole is to be removed rom the finished workpiece.
Dimensional deviations for untoleranced dimensions; Medium class according to IS : 2102-1969
Allowable deviations for dimensions without specified tolerances (first revision .
Inspection purposes, a centre drill which has not been repround shall be used.
For values of suitable limits of workpiece diameters for different sizes of centre holes, see
Designation -
A centre hole of Type A and diameter d = 16 mm shall be designated as:
Centre Hole A x
16
IS
: 2473
3
8/9/2019 Is 2473-1975 - Norma Furos de Centro
7/8
IS : 2473 - 1975
APPENDIX A
( Clause 2.6 )
LIMITS OF WORKPIECE DIAMETERS FOR DIFFERENT SIZES OF CENTRE HOLES
Nominal
.I
0.5
I
o-8
I
1'0
I
I
I.6
25
40
63
10.0
All dimensions in millimetres.
Diameter of Workpiece
Over
up to
-
4
4
6
6
IO
10
16
16
40
40 60
-
-
-
-
Weight of Manufactured
Workpiece, kg, ax
/ -
-
-
-
-
-
1600
~__ .~
4000
I
Note
-These values are for all types of centre holes (Types A, B and R) and are for information only.
EXPLANATORY NOTE
This standard was originally issued in the year 1963. The present revision has become
necessary as the standard on centre drills IS : 664-1963 has since een revised and published
splitting the original standard Into the following three sfandards:
IS :.6708-1972 Specification for centre drills, Type A
IS : 6709-1972 Specification for centre drills, Type 6
IS : 6710-1972 Specification for centre drills, Type D
This revision of IS :
2473 has also brought the standard
in line with the IS0 standard In
addition, suitable limits of workpiece diameters
for
different sizes of centre holes have been
included in an appendix far information.
8/9/2019 Is 2473-1975 - Norma Furos de Centro
8/8
AMENDMENT NO 2 J ANUARY 2 8
TO
IS 2 4 7 3 :1 9 7 5 DIMENSIONS FOR CENTRE HOLES
First Revision
Page 4, ExpIanatoty Note Substitute the following for the existing:
This standard was originally issued in the year 1963. The present revision has
become necessary as the standard on centre drills IS 664: 1963 has since been
revised and published splitting the original standard into the following three
standards:
IS 6708:1977 Specification for centre drills, Type A
K 6709:1977
Specification for centre drills, Type B
1S6710 :1977
Specification for centre drills, Type R
This revision of IS 2473 has also brought the standard in line with 1S0 866:
1975, 1S0 2540: 1973, and 1S0 2541 : 1972 for Type A, Type B and Type R
centre l+iolesrespectively. In addition, suitable limits of workpiece diameters for
different sizes of centre holes have been included in appendix for
information.
PG 20
ReprographyUnit,BIS,NewDelhi,India
Top Related