A4 Stainless Steel Hydraulic Compression Fittings combine the dimensional form of DIN 2353 with the material properties of grade A4-80 (316): superior, including marine and chloride environments, largely non-magnetic, service range approx. -200 °C to +400 °C. This page summarizes the grade data, its corrosion behavior in service, the comparable grades, and the sizes supplied.
Why Choose A4 Stainless Steel for Hydraulic Compression Fittings
Specified for marine, coastal and chemical applications. For hydraulic compression fittings, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | A4-80 (316) |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C |
| Corrosion characteristic | Superior, including marine and chloride environments |
Galvanic & Galling Considerations
Two important notes for stainless hydraulic compression fittings: (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.
Comparable Grades
For Hydraulic Compression Fittings, the alternative stainless grade is A2 (304). A2 (304) suits general indoor and outdoor service; A4 (316) adds molybdenum for marine and chloride environments. Where higher strength matters more than corrosion, switch to plated alloy-steel class 8.8 or 10.9.
Sizes of Hydraulic Compression Fittings Available in A4 Stainless Steel
| Tube OD (mm) | Nut length L (mm) | Nut width across flats (mm) | Tube bore (mm) | Max working pressure (bar) | Mating thread | Reference standard | Notes |
|---|---|---|---|---|---|---|---|
| 4 | 22 | 13 | 8 | 400 | M10x1 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 5 | 24 | 14 | 9 | 400 | M12x1.5 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 6 | 27 | 17 | 11 | 400 | M14x1.5 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 8 | 30 | 19 | 13 | 400 | M16x1.5 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 10 | 33 | 22 | 16 | 400 | M18x1.5 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 12 | 36 | 24 | 18 | 315 | M22x1.5 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 14 | 39 | 27 | 20 | 315 | M26x1.5 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 15 | 39 | 27 | 20 | 315 | M26x1.5 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 16 | 42 | 30 | 22 | 315 | M26x1.5 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 18 | 45 | 32 | 25 | 250 | M30x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 20 | 48 | 36 | 27 | 250 | M30x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 22 | 51 | 38 | 30 | 250 | M36x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 25 | 55 | 41 | 32 | 250 | M36x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 28 | 58 | 46 | 36 | 160 | M42x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 30 | 60 | 48 | 38 | 160 | M42x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 35 | 66 | 55 | 44 | 160 | M52x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 38 | 69 | 58 | 47 | 160 | M52x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |
| 42 | 74 | 65 | 52 | 100 | M60x2 | DIN 2353 / ISO 8434-1 | Compression hydraulic fitting |