For Hydraulic Compression Fittings in Grade 8.8 Steel, the controlling decisions are corrosion, strength and service temperature. This guide summarizes those three for Grade 8.8 Steel Hydraulic Compression Fittings and lists every size we supply.
Why Choose Grade 8.8 Steel for Hydraulic Compression Fittings
The workhorse medium-carbon alloy grade for structural joints. For hydraulic compression fittings, this matters when requires plating (zinc) for corrosion protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | class 8.8 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | up to approx. +300 °C |
| Corrosion characteristic | Requires plating (zinc) for corrosion protection |
Corrosion Behavior in Service
Carbon and alloy steel hydraulic compression fittings require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.
Comparable Grades
For Hydraulic Compression Fittings, class 10.9 or 12.9 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.
Sizes of Hydraulic Compression Fittings Available in Grade 8.8 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 |