What is DIN?
The DIN flange standards — principally DIN 2631 through DIN 2638 — are the older German dimensional series for PN-rated flanges, still widely specified on installed plant and on machinery built to German practice.
Key Takeaways
- DIN scope: Weld neck, slip on, blind, threaded and lap joint flanges across the PN range, with dimensions that in many sizes align with the EN 1092-1 series that superseded them.
- Size range: DN 10 to DN 1000 across the common series.
- Ratings: PN6 (DIN 2631), PN10 (DIN 2632), PN16 (DIN 2633), PN25 (DIN 2634), PN40 (DIN 2635), PN64 (DIN 2637) and higher.
- Material grades: Carbon steel to P250GH and equivalent, and stainless to 1.4301, 1.4401 and 1.4404.
- Kalp Alloys manufactures to DIN in Ahmedabad, India, with EN 10204 3.1 and 3.2 certification issued in its own name.
- Third-party inspection by SGS, BV, TUV or Lloyds can be witnessed at our plant before dispatch.
What DIN governs
The DIN flange standards — principally DIN 2631 through DIN 2638 — are the older German dimensional series for PN-rated flanges, still widely specified on installed plant and on machinery built to German practice.
Weld neck, slip on, blind, threaded and lap joint flanges across the PN range, with dimensions that in many sizes align with the EN 1092-1 series that superseded them.
Scope, sizes and ratings at a glance
The envelope below is the practical reference: what to state on a purchase order so the item that arrives is the item the line needs.
| Parameter | Detail |
|---|---|
| Size range | DN 10 to DN 1000 across the common series |
| Ratings | PN6 (DIN 2631), PN10 (DIN 2632), PN16 (DIN 2633), PN25 (DIN 2634), PN40 (DIN 2635), PN64 (DIN 2637) and higher |
| Material grades | Carbon steel to P250GH and equivalent, and stainless to 1.4301, 1.4401 and 1.4404 |
| DIN 2631 | PN6 weld neck |
| DIN 2632 | PN10 weld neck |
| DIN 2633 | PN16 weld neck |
| DIN 2634 | PN25 weld neck |
| DIN 2635 | PN40 weld neck |
| DIN 2637 | PN64 weld neck |
| Superseded by | EN 1092-1 |
The point buyers most often get wrong
DIN standards have been formally superseded by EN 1092-1, but the DIN number is still what appears on drawings for existing plant, and buyers replacing a flange on a twenty-year-old line reasonably order by the DIN number they can read on the isometric. We manufacture to both, and where a DIN number and an EN equivalent are dimensionally identical we state that on the quotation so the buyer knows the part will fit.
What Kalp Alloys manufactures to DIN
Kalp Alloys is a manufacturer, not a stockist. Production runs at our own facility at 5, Jay Vijay Industrial Estate, B/h. Akash Vikas Estate, Keval Kanta Road, Rakhial, Ahmedabad, which means the heat number stamped on the part traces to our own melt record and the mill test certificate is issued in the name of Kalp Alloys.
That matters on standard-led purchasing more than anywhere else, because an approved-vendor submission or a code-governed line has to show who made the part. A certificate passed down a trading chain names a mill the buyer has no relationship with and cannot query.
Grades supplied against DIN cover Carbon steel to P250GH and equivalent, and stainless to 1.4301, 1.4401 and 1.4404. Non-standard bores, thicknesses, drilling patterns and facing finishes are produced to customer drawing.
Ordering against DIN
State the dimensional standard, the size or NPS range, the rating or schedule, the facing where applicable, the material specification and grade, the quantity, and the certification level required. A quotation is typically returned within 24 hours.
Drawings for non-standard items can be sent by email or on WhatsApp at +91 81608 73937 and are reviewed by the technical team. Stock sizes dispatch in three to seven days; made-to-drawing items carry a firm lead time quoted at order confirmation. There is no minimum order on stock sizes and trial quantities are accepted.
Frequently Asked Questions
The DIN flange standards — principally DIN 2631 through DIN 2638 — are the older German dimensional series for PN-rated flanges, still widely specified on installed plant and on machinery built to German practice.
DN 10 to DN 1000 across the common series. Ratings covered are PN6 (DIN 2631), PN10 (DIN 2632), PN16 (DIN 2633), PN25 (DIN 2634), PN40 (DIN 2635), PN64 (DIN 2637) and higher.
Carbon steel to P250GH and equivalent, and stainless to 1.4301, 1.4401 and 1.4404.
Yes. Although EN 1092-1 has formally superseded the DIN series, we manufacture to DIN dimensions because replacement work on installed plant is still specified by DIN number.
In most common sizes the dimensions align, but this should be confirmed size by size rather than assumed. State both the DIN number and the mating flange on the enquiry and we will confirm before manufacture.
Yes. Kalp Alloys manufactures to DIN at its own facility at 5, Jay Vijay Industrial Estate, B/h. Akash Vikas Estate, Keval Kanta Road, Rakhial, Ahmedabad, and issues the EN 10204 3.1 or 3.2 mill test certificate in its own name rather than passing through a third-party mill certificate.
An EN 10204 3.1 mill test certificate as standard, stating the ordered standard, grade and heat number, with chemical and mechanical results and a dimensional inspection report. EN 10204 3.2 with third-party inspection by SGS, BV, TUV or Lloyds is arranged where the project requires it.