Clamp Identification Guide
The standard par excellence for hygiene and quick disassembly: pharmaceutical, brewing, food and beverage.
Principle
Clamp system
The Clamp system consists of two ferrules (tube ends with a flange), a gasket in the middle, and a clamp that holds everything together.
Measuring
How to measure a Clamp?
Forget about threads! For Clamp, two caliper measurements are enough:
1
Flange outside diameter
Measure the full width of the flat disc (collar) at the end. This defines the size of the clamp and the gasket.
2
Inside diameter (bore)
Measure the inside of the hole. This defines the standard (DIN or SMS) and avoids internal “steps”.
💡 The Clamp trap: The same flange diameter can correspond to several tube diameters. Example: a 50.5 mm flange is used for SMS 25, SMS 38, DIN 25, DIN 32 and DIN 40. Measuring the bore diameter is mandatory.
Small sizes
Micro-Clamps & Mini-Clamps
Used for small installations (laboratories, micro-breweries, fine dosing). Recognisable by their small flange.
Micro Clamp
25.2 mm
Flange outer ⌀
Mini Clamp
34.0 mm
Flange outer ⌀
SMS Clamp
SMS 3008 / ISO 2852
Very common in the dairy industry, breweries and cosmetics. Tube dimensions are often derived from inch measurements converted to millimetres.
| Size | ⌀ Flange | ⌀ Tube | ⌀ Bore | Clamp |
|---|---|---|---|---|
| SMS 13 (1/2″) | 25.2 mm | 12.7 mm | ~ 9.4 mm | Micro |
| SMS 19 (3/4″) | 25.2 mm | 19.05 mm | ~ 15.8 mm | Micro |
| SMS 25 (1″) | 50.5 mm | 25.0 / 25.4 mm | ~ 22.6 mm | Standard |
| SMS 38 (1.5″) | 50.5 mm | 38.0 / 38.1 mm | ~ 35.6 mm | Standard |
| SMS 51 (2″) | 64.0 mm | 51.0 mm | ~ 48.6 mm | Standard |
| SMS 63.5 (2.5″) | 77.5 mm | 63.5 mm | ~ 60.3 mm | Standard |
| SMS 76.1 (3″) | 91.0 mm | 76.1 mm | ~ 72.9 mm | Standard |
| SMS 104 (4″) | 119.0 mm | 104.0 mm | ~ 100.0 mm | Standard |
DIN Clamp
DIN 32676 — Series A
The European metric standard. Tube diameters fall on standardised millimetre sizes (DIN 11850 tubes).
| DN size | ⌀ Flange | ⌀ Tube | ⌀ Bore | Clamp |
|---|---|---|---|---|
| DN 15 | 34.0 mm | 19.0 mm | 16.0 mm | Mini |
| DN 20 | 34.0 mm | 23.0 mm | 20.0 mm | Mini |
| DN 25 | 50.5 mm | 29.0 mm | 26.0 mm | Standard |
| DN 32 | 50.5 mm | 35.0 mm | 32.0 mm | Standard |
| DN 40 | 50.5 mm | 41.0 mm | 38.0 mm | Standard |
| DN 50 | 64.0 mm | 53.0 mm | 50.0 mm | Standard |
| DN 65 | 91.0 mm | 70.0 mm | 66.0 mm | Standard |
| DN 80 | 106.0 mm | 85.0 mm | 81.0 mm | Standard |
| DN 100 | 119.0 mm | 104.0 mm | 100.0 mm | Standard |