Glossary Category:

316 stainless steel

316 stainless steel is a high carbon grade of the most commonly used austenitic class of stainless steels, with a high chromium and nickel content for superior resistance to corrosion. 316 SS has 18% chromium and 14% nickel for increased resistance to corrosion over 304 SS.  316 grade will resist …

360 stainless steel

360 stainless steel refers to the grade 360 molybdenum which is an alloy.  Stainless steel is a generic term which covers a large group of iron based alloys containing chromium, which provides a thin surface oxide for resistance to corrosion.  Stucchi offers Hydraulic check valves in 360 stainless steel.

630 stainless steel

Grade 630 stainless steel is in the martensitic class of stainless steels, with precipitation hardening often referred to as 17-4 PH.  This grade allows for excellent mechanical properties with a unique combination of high corrosion resistance with high strength.   Stucchi’s VUX Series Check Valve is available in AISI 630 stainless …


  BSP stands for British Standard Pipe Thread, also referred to as Whitworth thread and is common in the commonwealth countries and Australia.  The NPT is most common in the U.S. and Canada. The BSP comes in two types:       BSPP for parallel, or straight threads       BSPT for tapered threads BSPT …

carbon steel

Carbon steel is an alloy made of iron and carbon, with a higher carbon content than stainless steel.  Carbon steel has a lower melting point for more malleability, durability and improved heat distribution.  Carbon steel has a dull finish compared to stainless and is preferred in many manufacturing applications. Steel …

Crack Pressure

Crack pressure is the amount of pressure required on the upstream side of hydraulic valves to overcome the spring tension. If the crack pressure is reached, the check valve will open.  Pressure passing through below the crack pressure will close the spring to prevent back-flow.


  DIN (Deutsches Institut für Normung) is a port option found extensively in Germany and Europe.  Stucchi offers many hydraulic couplers available with international port options including DIN.

Flat Face Couplers

Flat face couplers describes flat end quick couplings designed to connect hydraulic lines with no fluid loss during quick disconnect.  Flat face, or flush face couplings, are considered environmentally friendly due to the zero leak performance even in applications with high pressure or high pressure impulses.

ISO 16028

ISO 16028 refers to the International Standards which detail requirements for performance of flat face (flush-face) type of hydraulic quick couplers used within a pressure of 20 MPa to 31.5 MPa.  Download the PDF of our ISO 16028 Flat Face ID Chart. Source: International Organization for Standardization

ISO 7241-B

ISO 7241-B lays down the interface dimensions and specifies basic performance requirements for two series of general-purpose quick-action couplings. Both series are in widespread use and have similar technological advantages. The distinction in usage is mainly geographical. Series “A” (covering sizes 6,3 to 50) is used predominantly in Europe and …