Gasket dimensions for flat ring and full face applications
ASME B16.21 class 150
Nominal bore |
Flat ring and full face gasket |
Flat ring gasket |
Full face gasket |
Nominal bore |
Inner diameter |
Outer diameter |
Outer diameter |
Bolt circle diameter |
Diameter of holes |
Number of bolt holes |
Inches |
mm |
Inches |
mm |
Inches |
mm |
Inches |
mm |
Inches |
mm |
1/2 |
27/32 |
21.4 |
1 7/8 |
47.6 |
3 1/2 |
88.9 |
2 3/8 |
60.3 |
5/8 |
15.9 |
4 |
1/2 |
3/4 |
1 1/16 |
27.0 |
2 1/4 |
57.2 |
3 3/4 |
95.3 |
2 3/4 |
69.9 |
5/8 |
15.9 |
4 |
3/4 |
1 |
1 5/16 |
33.3 |
2 5/8 |
66.7 |
4 1/4 |
108.0 |
3 1/8 |
79.4 |
5/8 |
15.9 |
4 |
1 |
1 1/4 |
1 21/32 |
42.1 |
3 |
76.2 |
4 5/8 |
117.5 |
3 1/2 |
88.9 |
5/8 |
15.9 |
4 |
1 1/4 |
1 1/2 |
1 29/32 |
48.4 |
3 3/8 |
85.7 |
5 |
127.0 |
3 7/8 |
98.4 |
5/8 |
15.9 |
4 |
1 1/2 |
2 |
2 3/8 |
60.3 |
4 1/8 |
104.8 |
6 |
152.4 |
4 3/4 |
120.7 |
3/4 |
19.1 |
4 |
2 |
2 1/2 |
2 7/8 |
73.0 |
4 7/8 |
123.8 |
7 |
177.8 |
5 1/2 |
139.7 |
3/4 |
19.1 |
4 |
2 1/2 |
3 |
3 1/2 |
88.9 |
5 3/8 |
136.5 |
7 1/2 |
190.5 |
6 |
152.4 |
3/4 |
19.1 |
4 |
3 |
3 1/2 |
4 |
101.6 |
6 3/8 |
161.9 |
8 1/2 |
215.9 |
7 |
177.8 |
3/4 |
19.1 |
8 |
3 1/2 |
4 |
4 1/2 |
114.3 |
6 7/8 |
174.6 |
9 |
228.6 |
7 1/2 |
190.5 |
3/4 |
19.1 |
8 |
4 |
5 |
5 9/16 |
141.3 |
7 3/4 |
196.9 |
10 |
254.0 |
8 1/2 |
215.9 |
7/8 |
22.2 |
8 |
5 |
6 |
6 5/8 |
168.3 |
8 3/4 |
222.3 |
11 |
279.4 |
9 1/2 |
241.3 |
7/8 |
22.2 |
8 |
6 |
8 |
8 5/8 |
219.1 |
11 |
279.4 |
13 1/2 |
342.9 |
11 3/4 |
298.5 |
7/8 |
22.2 |
8 |
8 |
10 |
10 3/4 |
273.1 |
13 3/8 |
339.7 |
16 |
406.4 |
14 1/4 |
362.0 |
1 |
25.4 |
12 |
10 |
12 |
12 3/4 |
323.9 |
16 1/8 |
409.6 |
19 |
482.6 |
17 |
431.8 |
1 |
25.4 |
12 |
12 |
14 |
14 |
355.6 |
17 3/4 |
450.9 |
21 |
533.4 |
18 3/4 |
476.3 |
1 1/8 |
28.6 |
12 |
14 |
16 |
16 |
406.4 |
20 1/4 |
514.4 |
23 1/2 |
596.9 |
21 1/4 |
539.8 |
1 1/8 |
28.6 |
16 |
16 |
18 |
18 |
457.2 |
21 5/8 |
549.3 |
25 |
635.0 |
22 3/4 |
577.9 |
1 1/4 |
31.8 |
16 |
18 |
20 |
20 |
508.0 |
23 7/8 |
606.4 |
27 1/2 |
698.5 |
25 |
635.0 |
1 1/4 |
31.8 |
20 |
20 |
24 |
24 |
609.6 |
28 1/4 |
717.6 |
32 |
812.8 |
29 1/2 |
749.3 |
1 3/8 |
34.9 |
20 |
24 |