Material specification page for socket set screws in Grade 8.8 Steel. Covers the grade designation (class 8.8), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to ISO 4026 / ISO 4029 / DIN 913-916.
Why Choose Grade 8.8 Steel for Socket Set Screws
The workhorse medium-carbon alloy grade for structural joints. For socket set screws, 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 socket set screws 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 Socket Set Screws, 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 Socket Set Screws Available in Grade 8.8 Steel
| Size | Pitch (mm) | Hex socket s (mm) | Engagement depth t min (mm) | Point diameter dp (mm) | End type | Reference standard |
|---|---|---|---|---|---|---|
| M1.6 | 0.35 | 0.7 | 0.7 | 0.8 | Flat point | ISO 4026 / DIN 913-916 |
| M1.6 | 0.35 | 0.7 | 0.7 | 0.8 | Cone point | ISO 4027 / DIN 913-916 |
| M1.6 | 0.35 | 0.7 | 0.7 | 0.8 | Dog point | ISO 4028 / DIN 913-916 |
| M1.6 | 0.35 | 0.7 | 0.7 | 0.8 | Cup point | ISO 4029 / DIN 913-916 |
| M2 | 0.4 | 0.9 | 0.9 | 1.0 | Flat point | ISO 4026 / DIN 913-916 |
| M2 | 0.4 | 0.9 | 0.9 | 1.0 | Cone point | ISO 4027 / DIN 913-916 |
| M2 | 0.4 | 0.9 | 0.9 | 1.0 | Dog point | ISO 4028 / DIN 913-916 |
| M2 | 0.4 | 0.9 | 0.9 | 1.0 | Cup point | ISO 4029 / DIN 913-916 |
| M2.5 | 0.45 | 1.3 | 1.1 | 1.5 | Flat point | ISO 4026 / DIN 913-916 |
| M2.5 | 0.45 | 1.3 | 1.1 | 1.5 | Cone point | ISO 4027 / DIN 913-916 |
| M2.5 | 0.45 | 1.3 | 1.1 | 1.5 | Dog point | ISO 4028 / DIN 913-916 |
| M2.5 | 0.45 | 1.3 | 1.1 | 1.5 | Cup point | ISO 4029 / DIN 913-916 |
| M3 | 0.5 | 1.5 | 1.4 | 2.0 | Flat point | ISO 4026 / DIN 913-916 |
| M3 | 0.5 | 1.5 | 1.4 | 2.0 | Cone point | ISO 4027 / DIN 913-916 |
| M3 | 0.5 | 1.5 | 1.4 | 2.0 | Dog point | ISO 4028 / DIN 913-916 |
| M3 | 0.5 | 1.5 | 1.4 | 2.0 | Cup point | ISO 4029 / DIN 913-916 |
| M4 | 0.7 | 2.0 | 2.0 | 2.5 | Flat point | ISO 4026 / DIN 913-916 |
| M4 | 0.7 | 2.0 | 2.0 | 2.5 | Cone point | ISO 4027 / DIN 913-916 |
| M4 | 0.7 | 2.0 | 2.0 | 2.5 | Dog point | ISO 4028 / DIN 913-916 |
| M4 | 0.7 | 2.0 | 2.0 | 2.5 | Cup point | ISO 4029 / DIN 913-916 |
| M5 | 0.8 | 2.5 | 2.5 | 3.5 | Flat point | ISO 4026 / DIN 913-916 |
| M5 | 0.8 | 2.5 | 2.5 | 3.5 | Cone point | ISO 4027 / DIN 913-916 |
| M5 | 0.8 | 2.5 | 2.5 | 3.5 | Dog point | ISO 4028 / DIN 913-916 |
| M5 | 0.8 | 2.5 | 2.5 | 3.5 | Cup point | ISO 4029 / DIN 913-916 |
| M6 | 1.0 | 3.0 | 3.0 | 4.0 | Flat point | ISO 4026 / DIN 913-916 |
| M6 | 1.0 | 3.0 | 3.0 | 4.0 | Cone point | ISO 4027 / DIN 913-916 |
| M6 | 1.0 | 3.0 | 3.0 | 4.0 | Dog point | ISO 4028 / DIN 913-916 |
| M6 | 1.0 | 3.0 | 3.0 | 4.0 | Cup point | ISO 4029 / DIN 913-916 |
| M8 | 1.25 | 4.0 | 4.0 | 5.5 | Flat point | ISO 4026 / DIN 913-916 |
| M8 | 1.25 | 4.0 | 4.0 | 5.5 | Cone point | ISO 4027 / DIN 913-916 |