Glassware Catalog

3.5mm O-Rings - Sigma-Aldrich Glassware Catalog


1.78mm Wall  •  2.6mm Wall  •  3.5mm Wall  •  5.3mm Wall


Viton A linear copolymer of vinylidene fluoride and hexafluoro-propylene;
good chemical resistance
Silicone Elastomer with high-temperature and ozone resistance
FETFE Fluoroelastomer with TFE additives and high chemical resistance
CAPFE A resilient rubber core encapsulated in non-porous FEP

O-ring measurement
  1. Measure the i.d. and wall thickness (mm)
    of the existing O-ring.
  2. Locate a replacement in the tables that follow.
  3. Ace Glass part numbers are provided for convenience.


Wall 3.5mm

I.d. (mm)
Viton
Catalog Number
Ace #
Silicone
Catalog Number
Ace #
18.6
7855-30
7855-230
20.2
7855-32
7855-232
21.8
7855-34
7855-234
23.3
7855-36
7855-236
25.0
7855-38
7855-238
28.2
7855-39
7855-239
29.7
7855-40
7855-240
34.5
7855-42
7855-242
40.9
7855-74
7855-274
47.2
7855-44
7855-244
50.4
7855-46
7855-246
53.6
7855-45
7855-245
56.7
7855-47
7855-247
59.9
7855-48
7855-248
63.1
7855-75
7855-275
78.9
7855-64
7855-264

I.d. (mm)
FETFE
Catalog Number
Ace #
CAPFE
Catalog Number
Ace #
18.6
7855-730
7855-830
20.2
7855-732
7855-832
21.8
7855-734
7855-834
23.3
7855-736
7855-836
25.0
7855-738
7855-838
28.2
7855-739
-
-
29.7
7855-740
7855-840
34.5
7855-742
7855-842
40.9
7855-774
7855-874
47.2
7855-744
7855-844
50.4
7855-746
7855-846
53.6
7855-745
7855-845
56.7
7855-747
7855-847
59.9
7855-748
7855-848
63.1
7855-775
7855-875
69.4
-
-
7855-877
72.6
7855-778
-
-
78.9
7855-764
-
-
134.4
-
-
7855-885


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