SMS: Stainless Metric Stock - The UK's leading distributer of metric stainless steel

The UK’s leading distributor of metric stainless steel

Image representing Data Sheets

Data Sheets

Stainless Steel   |   General Information

Metric DN/ND Tube and Fittings

What are Metric Tube and Fittings?
~ This is a lightweight range of welded tube, fittings and flanges with thin walls
~ An I/D based system
~ This range IS NOT to be confused with the ISO range of tube sizes which are sometimes INCORRECTLY called ‘ISO Metric’ – The ISO sizes are a thin walled, lower cost alternative to ANSI Pipe and are not very popular in the UK.
~ Note that an ‘Isometric’ is a pipe-work plan used by engineers and defined as follows: Isometric is a mathematical method of constructing a 3 dimensional object without using perspective. Isometric was an attempt to make drawing 3-D images easy and more realistic. The mathematics involved mean that all lengths when drawn at 30 degrees can be drawn using their true length (in other words lines aren't shortened as with oblique drawings). An isometric drawing shows two sides of the object and the top or bottom of the object. All vertical lines are drawn vertically, but all horizontal lines are drawn at 30 degrees to the horizontal.

Where is this range used?
~ Water and Waste Water Treatment
~ Pulp and Paper Industry
~ Food and Drink (Pre-Process)
~ Pharmaceutical (Bulk Handling)
~ Chemicals
~ Construction
~ Semi Conductor and other Clean Room Facilities

What are the advantages?
~ Lightweight
~ Demountable and re-usable
~ Simple to fabricate and erect
~ Quick and easy to commission
~ Easy to alter the system, make additions, etc.
~ Low footprint, handling weight and transport cost
~ Flexibility of fit-up with option of ‘spinning’/backing flanges

What is in the range?
~ Tube
~ Elbows, Tees, Reducers, End Caps
~ Collars and Flanges
~ Clips and Clamps

What is the size range?
~ 15mm to 900mm DN
~ 18mm to 910mm O/D
~ Wall Thickness 1.5mm to 5.0mm

What do DN/ND and O/D mean?
~ DN/ND = Nominal Diameter (I/D)
~ O/D = Outside/External Diameter
~ I/D = Internal Diameter

Backing Flanges may be:
~ Stainless Steel
~ Aluminium – These may have an epoxy coating
~ Mild Steel – These will have a coating such as PPA571 Grey Epoxy, Zinc Plating

What is the manufacturing specification?
~ Dimensional tolerances are to SS/EN/ISO 1127
~ Alloys are to BS EN 10088

What is the finish?
~ Sizes up to about 18mm DN may be bright annealed
~ Sizes up to about 70mm DN will be annealed and pickled
~ Larger sizes will be pickled but may be unannealed

For Further Information

Please download or request a hard copy of our Brochure on this product range

Download PDF


This Data is indicative only and as such is not to be relied upon in place of the full specification. In particular, mechanical property requirements vary widely with temper, product and product dimensions. All information is based on our present knowledge and is given in good faith. No liability will be accepted by the Company in respect of any action taken by any third party in reliance thereon.

Please note that the 'Datasheet Update' date shown above is no guarantee of accuracy or whether the datasheet is up to date.

The information provided in this datasheet has been drawn from various recognised sources, including EN Standards, recognised industry references (printed & online) and manufacturers’ data. No guarantee is given that the information is from the latest issue of those sources or about the accuracy of those sources.

Material supplied by the Company may vary significantly from this data, but will conform to all relevant and applicable standards.

As the products detailed may be used for a wide variety of purposes and as the Company has no control over their use; the Company specifically excludes all conditions or warranties expressed or implied by statute or otherwise as to dimensions, properties and/or fitness for any particular purpose, whether expressed or implied.

Advice given by the Company to any third party is given for that party’s assistance only and without liability on the part of the Company. All transactions are subject to the Company’s current Conditions of Sale. The extent of the Company’s liabilities to any customer is clearly set out in those Conditions; a copy of which is available on request.