Datasheet

© Freudenberg Simrit GmbH & Co. KG | Technical Manual 2007568
Technical Principles | O-Rings and Static Seals
Grade attributes according to DIN 3771
ISC O-Rings are supplied in two different design imple-
mentation qualities to cover all requirement situations
that arise with practical applications.
Grade attribute N (Normal quality), quality limit
range AQL 1.0 or by agreement.
These ISC O-Rings fulfil very high quality demands and
are suitable for all conventional application situations.
It is irrelevant whether these involve static or dynamic
seals.
ISC O-Rings in standard quality are kept in stock.
Grade attribute S (Special quality), quality limit
range AQL 0.65 or by agreement.
These ISC O-Rings are only considered for application
situations in which the highest demands for design
implementation and sealing effectiveness are made.
■
■
ISC O-Ring in special quality grades require significant-
ly greater manufacturing and quality assurance efforts
than ISC O-Rings in normal quality. Thus, they are also
significantly more expensive. They must be ordered with
the note "ISC O-Rings according to grade attribute S"
while at the same time specifying the intended applica-
tion. ISC O-Rings in special quality grades are not kept
in stock. Normal quality grade ISC O-Rings and the
special quality grades are distinguished by their permis-
sible attribute designations. The permissible tolerance
levels are the same for both design implementation
grades. The listed attribute designations are to be con-
sidered as recommended values for both manufacturers
and users. Visual inspection is made of the attribute
designations for the different grade attributes as a part
of the manufacturing and control processes. Limit sam-
ples serve as the basis for this test, which is established
according to → Tbl. 15. Special arrangements are
possible for special applications.
Type of
deviation
Diagrammatic
presentation
Dimen-
sions
Grade attribute N Grade attribute S
d2 according to DIN 3771,
Part 1
d2 according to DIN 3771,
Part 10
1,80 2,65 3,55 5,30 7,00 1,80 2,65 3,55 5,30 7,00
Largest size
Offset and shape
deviations
e
e
e
e 0,08 0,10 0,13 0,15 0,15 0,08 0,08 0,10 0,12 0,13
Bead, burs, offset
combined
f
f
f 0,10 0,12 0,14 0,16 0,18 0,10 0,10 0,13 0,16 0,15
Notch
g
h
g 0,18 0,27 0,36 0,53 0,70 0,10 0,15 0,20 0,20 0,30
h 0,08 0,08 0,10 0,10 0,13 0,08 0,08 0,10 0,10 0,13
Deburred area
–
Deviations from round cross-sections are permissible if the flattened area goes
seamlessly into the curvature and lies within the permissible tolerance levels.
Flow marks (radial
expansion is not
permissible)
k
j
j
0,05 x d
1
or
1)
0,03 x d
1
or
1)
1,5 1,5 6,5 6,5 6,5 1,5 1,5 5 5 5
k 0,08 0,05
Pits, indentations
m
l
l
l 0,60 0,80 1,00 1,30 1,70 0,15 0,25 0,40 0,63 1,00
Depth 0,08 0,08 0,10 0,10 0,13 0,08 0,08 0,10 0,10 0,13
Foreign material – – Not permissible
1)
Depending on which number is larger
Tbl. 15 Grade attributes according to DIN 3771 – Part 4