Hastelloy B3 threaded flanges, manufactured strictly to ASME B16.5, combine precise dimensional accuracy with exceptional resistance to hydrochloric acid, sulfuric acid, and other reducing media.
Threaded (screwed) flanges feature internal NPT threads that allow direct connection to threaded pipe without welding. This design is ideal for low-to-moderate pressure systems, small-bore piping, and maintenance-prone installations in chemical plants, pharmaceutical facilities, and acid-handling operations. Our Hastelloy B3 versions meet or exceed ASTM B564, ASME B16.5, and international equivalents, including BS, DIN, and GOST.
Hastelloy B3 Material Advantages
Hastelloy B3 offers superior thermal stability compared to its predecessor, B2, minimizing carbide precipitation during welding or heating. Key composition (weight %):
Nickel: Balance (≥65 %)
Molybdenum: 28.0–30.0 %
Chromium: 1.0–3.0 %
Iron: ≤2.0 %
Cobalt: ≤3.0 %
Manganese: ≤3.0 %
Tungsten: ≤3.0 %
Minimum mechanical properties (annealed, per ASTM B564):
Yield strength: 45 ksi (310 MPa)
Tensile strength: 110 ksi (760 MPa)
Elongation: 40 %
Hardness: ≤100 HRB
Density is approximately 9.22 g/cm³. These properties ensure the flanges retain strength and ductility across a wide temperature range while resisting pitting, crevice corrosion, and stress-corrosion cracking far better than 316L stainless or other nickel alloys in pure reducing acids.
ASME B16.5 Threaded Flange Dimensions
ASME B16.5 defines dimensions, tolerances, and pressure-temperature ratings for threaded flanges NPS ½ through 24 in Classes 150 through 2500.
Below are the complete specification tables for the two most commonly specified classes. All dimensions are in inches. Raised face height is 1/16 in unless otherwise noted. Threads are NPT.
Class 150 Hastelloy B3 Threaded Flange Dimensions
|
NPS |
OD (O) |
Thickness (T) |
Raised Face (R) |
Bolt Circle (C) |
No. Holes |
Bolt Hole Dia |
Approx. Weight (lb) |
|
½ |
3.50 |
0.44 |
1.38 |
2.38 |
4 |
0.63 |
1 |
|
¾ |
3.88 |
0.50 |
1.69 |
2.75 |
4 |
0.63 |
2 |
|
1 |
4.25 |
0.56 |
2.00 |
3.13 |
4 |
0.63 |
2 |
|
1¼ |
4.63 |
0.63 |
2.50 |
3.50 |
4 |
0.63 |
3 |
|
1½ |
5.00 |
0.69 |
2.88 |
3.88 |
4 |
0.63 |
4 |
|
2 |
6.00 |
0.75 |
3.63 |
4.75 |
4 |
0.75 |
5 |
|
2½ |
7.00 |
0.88 |
4.13 |
5.50 |
4 |
0.75 |
7 |
|
3 |
7.50 |
0.94 |
5.00 |
6.00 |
4 |
0.75 |
9 |
|
3½ |
8.50 |
0.94 |
5.50 |
7.00 |
8 |
0.75 |
13 |
|
4 |
9.00 |
0.94 |
6.19 |
7.50 |
8 |
0.75 |
17 |
|
5 |
10.00 |
0.94 |
7.31 |
8.50 |
8 |
0.88 |
20 |
|
6 |
11.00 |
1.00 |
8.50 |
9.50 |
8 |
0.88 |
26 |
|
8 |
13.50 |
1.13 |
10.63 |
11.75 |
8 |
0.88 |
45 |
|
10 |
16.00 |
1.19 |
12.75 |
14.25 |
12 |
1.00 |
70 |
|
12 |
19.00 |
1.25 |
15.00 |
17.00 |
12 |
1.00 |
110 |
|
14 |
21.00 |
1.38 |
16.25 |
18.75 |
12 |
1.13 |
140 |
|
16 |
23.50 |
1.44 |
18.50 |
21.25 |
16 |
1.13 |
180 |
|
18 |
25.00 |
1.56 |
21.00 |
22.75 |
16 |
1.25 |
220 |
|
20 |
27.50 |
1.69 |
23.00 |
25.00 |
20 |
1.25 |
285 |
|
22 |
29.50 |
1.81 |
25.25 |
27.25 |
20 |
1.38 |
355 |
|
24 |
32.00 |
1.88 |
27.25 |
29.50 |
20 |
1.38 |
|
Class 300 Hastelloy B3 Threaded Flange Dimensions
|
NPS |
OD (O) |
Thickness (T) |
Raised Face (R) |
Bolt Circle (C) |
No. Holes |
Bolt Hole Dia |
Approx. Weight (lb) |
|
½ |
3.75 |
0.56 |
1.38 |
2.63 |
4 |
0.63 |
2 |
|
¾ |
4.63 |
0.63 |
1.69 |
3.25 |
4 |
0.75 |
3 |
|
1 |
4.88 |
0.69 |
2.00 |
3.50 |
4 |
0.75 |
3 |
|
1¼ |
5.25 |
0.75 |
2.50 |
3.88 |
4 |
0.75 |
4 |
|
1½ |
6.13 |
0.81 |
2.88 |
4.50 |
4 |
0.88 |
6 |
|
2 |
6.50 |
0.88 |
3.63 |
5.00 |
8 |
0.75 |
8 |
|
2½ |
7.50 |
1.00 |
4.13 |
5.88 |
8 |
0.88 |
12 |
|
3 |
8.25 |
1.13 |
5.00 |
6.63 |
8 |
0.88 |
16 |
|
3½ |
9.00 |
1.19 |
5.50 |
7.25 |
8 |
0.88 |
21 |
|
4 |
10.00 |
1.25 |
6.19 |
7.88 |
8 |
0.88 |
27 |
|
5 |
11.00 |
1.38 |
7.31 |
9.25 |
8 |
0.88 |
35 |
|
6 |
12.50 |
1.44 |
8.50 |
10.63 |
12 |
0.88 |
50 |
|
8 |
15.00 |
1.63 |
10.63 |
13.00 |
12 |
1.00 |
81 |
|
10 |
17.50 |
1.88 |
12.75 |
15.25 |
16 |
1.13 |
124 |
|
12 |
20.50 |
2.00 |
15.00 |
17.75 |
16 |
1.25 |
185 |
|
14 |
23.00 |
2.13 |
16.25 |
20.25 |
20 |
1.25 |
250 |
|
16 |
25.50 |
2.25 |
18.50 |
22.50 |
20 |
1.38 |
295 |
|
18 |
28.00 |
2.38 |
21.00 |
24.75 |
24 |
1.38 |
395 |
|
20 |
30.50 |
2.50 |
23.00 |
27.00 |
24 |
1.38 |
505 |
|
22 |
33.00 |
2.63 |
25.25 |
29.25 |
24 |
1.63 |
640 |
|
24 |
36.00 |
2.75 |
27.25 |
32.00 |
24 |
1.63 |
790 |
Notes:
Tolerances: OD ±0.06 in (up to 24 in); bolt hole location ±0.03 in.
Class 150 flanges have no counterbore; Class 300 and higher include a counterbore for thread relief.
Weights shown are approximate for reference. Actual Hastelloy B3 weights are ~17% higher due to alloy density.
Pressure ratings at ambient temperature: Class 150 ≈ 285 psi; Class 300 ≈ 740 psi.
Classes 600, 900, 1500, and 2500 are available for NPS ½–2½. Contact us for those detailed dimensions.
