Standards · Tool
Standards translator: what does that mean in the other world?
Enter nominal size, pressure rating, thread or material – the tool names the counterpart of the other standards world, the standard behind it and the point at which the translation is only an approximation. Because it almost always is: DN 50 is NPS 2, but PN 16 is not Class 150, and NPT is not R.
- Inputs
- nominal size DN/NPS · pressure rating PN/Class · thread · material
- Output
- counterpart with standard, approximation warning, link to the comparison page
- Basis
- stock data layer (dimension tables, thread tables, material comparison) – no standard tables
- Stage
- stage 1 without Class flange tables; bolt circle and bolt comparison follow with the ASME dimensional drawing
Standards translator
Bolt circles and bolts of the Class flanges follow with the ASME dimensional drawing.
Values from our stock tables with standard and edition – no standard tables reproduced.
How to read the output
Every line of the result carries three things: the counterpart, the standard with edition and a verdict – “fits”, “appears to fit” or “does not fit” as on Mixing standards worlds. The nominal size is the most harmless translation: DN 50 and NPS 2 name the same 60.3 mm pipe, but in four nominal sizes the outside diameters differ. The pressure rating is the most dangerous: PN 16 and Class 150 lie close together at room temperature, not at temperature – the tool names the counterpart only with a warning and refers to EN 1092-1 versus ASME B16.5.
The tool identifies the thread from designation or from outside diameter and pitch – and says whether the counterpart seals (flank angle 55° against 60°, sealing principle). For the material it shows UNS number and ASTM grades for the material number and beside them the limits of comparison; the whole table is on Materials between the worlds.
The master data of the tool
| Thread | Standard | Form | Flank angle | Taper | Sealing principle |
|---|---|---|---|---|---|
| R (taper external thread) | EN 10226-1 (ISO 7-1) | external, taper | 55° | 1:16 | sealing in the thread with sealant |
| Rp (parallel internal thread) | EN 10226-1 (ISO 7-1) | internal, parallel | 55° | – | sealing in the thread against a tapered R |
| Rc (taper internal thread) | EN 10226-2 (ISO 7-1) | internal, taper | 55° | 1:16 | sealing in the thread |
| G (parallel, not sealing in the thread) | ISO 228-1 | external and internal, parallel | 55° | – | sealing on a face with a gasket, not in the thread |
| NPT (National Pipe Taper) | ASME B1.20.1 | external and internal, taper | 60° | 1:16 | sealing in the thread with sealant (NPTF dry-seal without) |
Show full table · more than 20 rows
| Material | UNS | ASTM grades |
|---|---|---|
| 1.4301 X5CrNi18-10 | S30400 | ASTM A182 F304, ASTM A403 WP304 |
| 1.4306 X2CrNi19-11 | S30403 | ASTM A182 F304L, ASTM A403 WP304L |
| 1.4307 X2CrNi18-9 | S30403 | ASTM A182 F304L, ASTM A403 WP304L |
| 1.4401 X5CrNiMo17-12-2 | S31600 | ASTM A182 F316, ASTM A403 WP316 |
| 1.4404 X2CrNiMo17-12-2 | S31603 | ASTM A182 F316L, ASTM A403 WP316L |
| 1.4435 X2CrNiMo18-14-3 | S31603 | ASTM A182 F316L |
| 1.4436 X3CrNiMo17-13-3 | S31600 | ASTM A182 F316, ASTM A403 WP316 |
| 1.4541 X6CrNiTi18-10 | S32100 | ASTM A182 F321, ASTM A403 WP321 |
| 1.4550 X6CrNiNb18-10 | S34700 | ASTM A182 F347, ASTM A403 WP347 |
| 1.4571 X6CrNiMoTi17-12-2 | S31635 | ASTM A182 F316Ti |
| 1.0345 P235GH | K02501 | ASTM A106 Gr. A, ASTM A234 WPA |
| 1.0425 P265GH | K03006 | ASTM A106 Gr. B, ASTM A234 WPB |
| 1.0426 P280GH | K03504 | ASTM A105 |
| 1.0460 P250GH | K03504 | ASTM A105 |
| 1.4410 X2CrNiMoN25-7-4 | S32750 | ASTM A182 F53 |
| 1.4462 X2CrNiMoN22-5-3 | S31803 | ASTM A182 F51 |
| 1.0451 P215NL | K03008 | ASTM A333 Gr. 1 |
| 1.0453 P265NL | K03006 | ASTM A333 Gr. 6, ASTM A420 WPL6 |
| 1.0477 P285NH | K03011 | ASTM A350 LF2 Cl. 1, ASTM A350 LF2 Cl. 2 |
| 1.0478 P285QH | K03011 | ASTM A350 LF2 Cl. 1, ASTM A350 LF2 Cl. 2 |
| 1.0571 P355QH1 | K03011 | ASTM A350 LF2 Cl. 1 |
| 1.5637 12Ni14 | K31918 / K32025 | ASTM A333 Gr. 3, ASTM A350 LF3 Cl. 1, ASTM A420 WPL3 |
| 1.4903 X10CrMoVNb9-1 | K90901 | ASTM A182 F91, ASTM A234 WP91 |
| 1.5415 16Mo3 | K12821 / K12822 | ASTM A182 F1, ASTM A234 WP1 |
| 1.7335 13CrMo4-5 | K11562 / K11564 / K11572 / K11597 | ASTM A182 F11 Cl. 2, ASTM A182 F12 Cl. 2, ASTM A234 WP11 Cl. 1, ASTM A234 WP12 Cl. 2 |
| 1.7362 X11CrMo5 | K41545 | ASTM A182 F5, ASTM A234 WP5 |
| 1.7380 10CrMo9-10 | K21590 | ASTM A182 F22 Cl. 3, ASTM A234 WP22 Cl. 1 |
| 1.7383 11CrMo9-10 | K21590 | ASTM A182 F22 Cl. 3 |
| 1.7386 X11CrMo9-1 | K90941 | ASTM A234 WP9 |
| 1.5682 X10Ni9 | K81340 | ASTM A333 Gr. 8, ASTM A420 WPL8 |
What the tool cannot do
It replaces neither a specification nor a standard. It does not say whether a Class 150 flange may be bolted to a PN 16 flange – it says that the two are different. It knows no pressure-temperature curves, no approval under the Pressure Equipment Directive and no company standard of your operator. Bolt circles and numbers of bolts of the Class flanges come with the ASME dimensional drawing; until then the tool refers to the ASME dimension table.
Further reading
The standards-worlds topic: Why standards are replaced · How binding standards are · Standards worlds by region · EN and ASME compared · Mixing standards worlds · Materials between the worlds.
From our knowledge base: Standards guide · ASME and ASTM profiles · EN 1092-1 versus ASME B16.5 · ASME flange dimensions · Standards comparison · Inspection documents to EN 10204 · Reading markings · Identifying a component.
Frequently asked questions
Which ASME flange corresponds to a DN 100 PN 16 flange?
There is no interchangeable equivalent - NPS 4 class 150 is the nearest rating, bolt pattern and facing differ; the standards translator shows the differences per component.
Is DN 50 the same as NPS 2?
As a name yes – both designate the pipe with 60.3 mm outside diameter. DN is a dimension in no size, NPS from 14 inch the outside diameter in inches. The rule of thumb: DN is not NPS, PN is not Class.
Which Class corresponds to PN 16?
None exactly. Class 150 lies in a similar range at room temperature, the curves diverge with temperature, and the flanges are not dimensionally identical in most nominal sizes. The tool names Class 150 as the neighbour – with a warning.
Where do the values come from?
From our stock tables: dimension tables (EN 1092-1, ASME dimensions), thread tables (EN 10226-1, ISO 228-1, ASME B1.20.1), material comparison from the ASME/ASTM profiles. Every value carries its standard; we reproduce no standard tables.
Can I copy the result into my order?
As a hint, not as a specification. Order the counterpart with standard, edition, type and material – and tell us the destination country; we check the pairing.
Two worlds in one enquiry?
Tell us standard, edition and destination country – we tell you what fits from stock and what needs a counterpart.
Send an inquiryYour inquiry to Zickwolff
Send us what you have – designation, standard, quantity, date. We will clarify the rest with you.
One item or a question
Send inquiry
Not in stock? We procure it – single items too.
Designation, standard and quantity are enough.
Several items
Send bill of materials
200 items? One parts list is enough – we deliver complete.
Attach it as a file.
Helpful if already known: project and country, date needed, certificates, packaging and language of the packing lists. If anything is missing, we will ask.
It is urgent
Request express
When do you need it? Express delivery, to the site if required.
Tell us by when you need the material – we will tell you what is possible.
As of 2 October 2026. Statements taken from forewords and scopes of standards, legal texts (Pressure Equipment Directive, German Betriebssicherheitsverordnung), standards bodies, inspection bodies and technical articles; regional list approved 30 September 2026. No standard text reproduced. Not legal advice.