10 inch Class 150 flange dimensions
ASME B16.5 Class 150 flange dimensions for 10 inch (DN 250) pipe. The same bolting dimensions apply to weld neck, slip-on, blind, socket weld, threaded and lap joint flanges of this size and class.
| Nominal size | 10" (DN 250) |
| Pipe OD (bore end) | 273.1 mm |
| Flange outside diameter | 405 mm (15.94 in) |
| Minimum thickness (incl. 1.6 mm RF) | 28.6 mm (1.13 in) |
| Bolt circle diameter (PCD) | 362.0 mm (14.25 in) |
| Number of bolt holes | 12 |
| Bolt hole diameter | 1.00 in (25.4 mm) |
| Stud bolt diameter | 7/8" UNC |
| Raised face height | 1.6 mm (1/16 in) |
A complete 10" Class 150 joint needs 12 stud bolts of 7/8" diameter with 24 heavy hex nuts and one gasket.
Class 150 vs Class 300 — 10"
| Dimension | Class 150 | Class 300 |
|---|---|---|
| OD | 405 mm | 445 mm |
| Thickness | 28.6 mm | 46.1 mm |
| Bolt circle | 362.0 mm | 387.4 mm |
| Bolts | 12 × 7/8" | 16 × 1" |
Class 150 and Class 300 flanges do not bolt together — see 10" Class 300.
Frequently asked questions
What is the OD of a 10 inch Class 150 flange?
405 mm (15.94 in) per ASME B16.5.
How many bolts does a 10 inch Class 150 flange have?
12 bolts of 7/8 inch diameter in 1.00 inch holes on a 362.0 mm bolt circle.
What is the thickness of a 10 inch Class 150 flange?
The minimum flange thickness is 28.6 mm, including the 1.6 mm raised face.
Last updated 2026-11-02