TABLE
1 PHYSICAL REQUIREMENTS FOR GENERAL PURPOSE
FELTS (Clause
6.1)
TYPE
THICKNESS
mm
DENSITY
gm/ccm
TENSILE
STRENGTH
kN/mm2
SPLITING
RESISTANCE
N/cm
LENTH
WIDTH
FINISH
Hard
As
agreed
(See
Note No.1)
0.60
4100
75
As declared
or agreed
(See Note.3)
As declared
or agreed
+/-2 Percent
Milled
Extra Hard
0.46
3400
65
Milled
Extra Firm
0.40
2900
55
Milled
Firm
0.34
2400
40
Milled
Medium Firm
0.27
1500
26
Milled
Medium
0.23
1400
22
Milled
Soft
0.18
900
(See Note.2)
Hardened
Extra Soft
0.15
(See Note.2)
(See Note.2)
Hardened
Method of Test
B-2
B-3
B-4
B-5
IS : 1954
Note
1
The
common thickness of felts are 1.5, 3, 6,10,13,16,19,22
& 25 mm
Note
2
The requirements
of tensile strength and splitting resistance
are recomandatory and shall be applicable, if
specifically agreed between the buyer and the
seller.
However,the splitting resistance shall not be
applicable incase of felts having thickness of
6mm and below and also in case of soft &
extra soft Felts. Tensile strength shall not
be applicable in case of extra soft felt.
Note
3
No negative
tolerance shall be permitted in length of felt.
TABLE
2 PHYSICAL REQUIREMENTS FOR PRECISION FELTS (Clause
6.1)
TYPE
THICKNESS
mm
DENSITY
gm/ccm3
TENSILE
STRENGTH
kN/mm2
SPLITING
RESISTANCE
N/cm
Oil
Retention
RESISTANCE
Percent
LENGTH
m
WIDTH
cm
Extra Hard
As
agreed
(See
Note No.1)
0.60
5500
100
80
As declared
or agreed
+/-2%
(See Note No.3)
Hard
0.46
4500
87
90
Extra firm
0.40
3800
70
100
Firm
0.34
3100
50
120
Medium firm
0.27
2000
35
140
Medium
0.23
1800
30
150
Soft
0.18
1200
25
160
Extra Soft
0.15
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Method of Test
B-2
B-3
B-4
B-5
IS : 1954
Note
1
The
common thickness of felts are 1.5, 3,
6,10,13,16,19,22,25 & 50 mm
Note
2
The
splitting resistance shall not be determined
in case of felts thickness of 6mm &
below.
Note
3
No
negative tolerance shall be permitted
in length of felt.
GENERAL
PURPOSES FELTS SHALL BE AS FOLLOWS
Felt
Thickness
Tolerance
on Nominal
& Density
Tolerance
on
Nominal & Density
4.0 mm and below
+/- 20 perce
+/- 25
(See Note)
4.1 mm to 10 mm
+/-
15 perce
+/- 20
(See Note)
Above
10 mm
+/- 10 perce
+/- 15
Note
- The minimum tolerance of +/- 0.5
mm shall be
permited on the individual value of
thickness.
TOLERANCE
OF PRECISION FELTS SHALL BE AS FOLLOWS
Felt
Thickness
ToleranceThickness
Tolerance Individual
of Thickness
Tolerance Nominal
Up
to 10 mm
+/- 7.5
+/- 12.5 (See
Note)
+/- 10 perce
Above
10 mm
+/- 5
+/- 10 perce(See
Note)
+/- 7.5
Note
- The minimum tolerance of +/- 0.5
mm shall be permited on the
individual value of thickness.
