Flange Identification & Size Check Tool
Two tools in one. Identify an unmarked flange and check its size from a measured OD and PCD, or look up the OD, PCD, thickness and bolt-hole count for any flange by type. A free flange identification and measurement tool covering BS 10, ASME B16.5, DIN 2527 and IS:6392.
What do you have?
Measure these two
OD is the full outside diameter, edge to edge.
PCD is the bolt-circle: measure from the centre of one bolt hole straight across to the centre of the hole opposite. Enter both and the tool finds the match — add the flange thickness (width) to confirm.
How to identify an unmarked flange
If you have a flange in hand with no markings, three measurements are enough to find what it is.
Measure the OD
Measure the full outside diameter of the flange face, edge to edge, in millimetres.
Measure the PCD
Measure the bolt-circle diameter — centre of one hole to the centre of the hole opposite. Enter both OD and PCD.
Confirm by thickness / holes
If two standards match, add the flange thickness or count the bolt holes to pin down the exact table.
Flange standards in this tool
Both modes work across the same verified dataset. Every result shows the governing standard.
Tables D, E, F, H, J, K
British Standard plain flange tables graded by working steam pressure, Table D (up to 50 lb/in²) to Table K (350–450 lb/in²). Sizes in inches.
Class 150, 300, 400, 600
American Standard pipe flange classes used across oil & gas, refinery and process piping. Sizes in inches (NPS).
ND-10, ND-16, ND-25, ND-40
German Standard plate-flange pressure nominals (PN10–PN40), common on pumps, valves and European-spec lines. Sizes in mm.
Table 17
Indian Standard plate flange, nominal pressure 1.6 N/mm². Sizes in mm.
OD, PCD, Thickness, Holes
The four dimensions that decide whether a flange fits and bolts up correctly to the mating flange, valve or pump.
Supply against any table
Vijay Sales Corporation stocks and supplies MS flanges across these standards. Send the tool's enquiry for net rates and availability.
Methodology & sources
The dimensional values were transcribed directly from the published plain-flange dimension tables for BS 10:1962 (Tables D, E, F, H, J and K), ASME B16.5-1988 (slip-on flanges, Class 150 / 300 / 400 / 600), DIN 2527 (ND-10, ND-16, ND-25 and ND-40 plate flanges) and IS:6392 (Table 17 plate flange). For each flange type and nominal size we record outside diameter (OD), pitch circle diameter (PCD), flange thickness and number of bolt holes — 369 entries across 15 references.
Each entry was cross-checked field by field against the source tables before publishing. Look-up mode returns the recorded dimensions for a chosen type and size. Identify mode compares your measured OD and PCD against every entry within a ±2.5 mm tolerance, scores each candidate by how closely it matches, and lists the closest first — because a flange measured by hand will not read the exact nominal figure.
This page is written and maintained by Punya Gupta, Chief Operating Officer of Vijay Sales Corporation, a third-generation Delhi-based distributor of industrial pipeline products established in 1961, and is reviewed for dimensional accuracy on each update. If you spot a discrepancy against your own approved standard, please contact us — corrections are welcome.
Flange identification & dimension questions
Common questions about identifying flanges, reading dimensions and using this tool.
How do I identify an unmarked flange?
Measure the outside diameter (OD) and the bolt-circle diameter (PCD), enter both into Identify mode, and the tool returns the closest matching standard, table and size. Adding thickness or hole count narrows it further.
How do I check or measure a flange size?
Use a tape or vernier to measure the flange outside diameter (OD) edge to edge, then the bolt-circle (PCD) from the centre of one hole to the centre of the hole opposite. Enter both into the tool to check the flange size and find its matching standard. The flange thickness (width) and bolt-hole count help confirm the exact table.
What is the difference between OD and PCD?
OD is the outside diameter of the flange; PCD is the diameter of the circle through the centres of the bolt holes. Two flanges can share an OD but differ on PCD, so both are needed to identify a flange.
Why does it show more than one possible match?
Different standards sometimes use very similar OD and PCD at a given size. When your measurement is within tolerance of more than one flange, the tool lists all close matches, closest first, so you can confirm by thickness or bolt-hole count.
Are Table E and Class 150 the same?
No. Table E is a British Standard (BS 10:1962) drilling; Class 150 is American (ASME B16.5). Their OD, PCD and bolt patterns differ and they are not interchangeable. Confirm the standard before ordering.
Can I send the result as an enquiry?
Yes. Both modes build a WhatsApp message with the flange type, size and dimensions, ready to send to Vijay Sales Corporation for price and availability.
Need MS flanges supplied?
Vijay Sales Corporation stocks and supplies MS flanges across BS 10, ASME B16.5, DIN 2527 and IS:6392 standards. Identify or confirm your flange above, then send us the enquiry for net rates and availability.