Property Class 8.8 Steel Socket Set Screws, UNC (Flat, Cone, Dog and Cup Point) combine the dimensional form of ASME B18.3 with the material properties of grade ISO 898-1 property class 8.8: requires plating (zinc) for corrosion protection, magnetic, service range commonly limited to approx. +300 °C; confirm against the coating and the load. This page summarizes the grade data, its corrosion behavior in service, the comparable grades, and the sizes supplied.
Why Choose Property Class 8.8 Steel for Socket Set Screws, UNC (Flat, Cone, Dog and Cup Point)
The workhorse medium-carbon alloy class for structural joints. For socket set screws, unc (flat, cone, dog and cup point), this matters when requires plating (zinc) for corrosion protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 898-1 property class 8.8 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | commonly limited to approx. +300 °C; confirm against the coating and the load |
| Corrosion characteristic | Requires plating (zinc) for corrosion protection |
Galvanic & Galling Considerations
For socket set screws, unc (flat, cone, dog and cup point) in steel, the dominant compatibility issue is hydrogen embrittlement at high property classes (10.9 and above) when electroplated. Plating must be followed by an appropriate baking treatment, or a non-electroplated finish (mechanical zinc, zinc flake) should be substituted.
Comparable Grades
For Socket Set Screws, UNC (Flat, Cone, Dog and Cup Point), 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, UNC (Flat, Cone, Dog and Cup Point) Available in Property Class 8.8 Steel
| Size | Type | Pitch P (mm) | t (mm) | dp (mm) | dt (mm) | df (mm) | Hex socket s (mm) | z (mm) | Length range l (in) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|
| #0 | Hexagon socket set screws with flat point | 0.318 | 1.27 | 0.762 | 0.305 | 0.978 | 0.711 | 0.381 | 1/16"~1 1/2" | ASME B18.3 |
| #0 | Hexagon socket set screws with cone point | 0.318 | 1.27 | 0.762 | 0.305 | 0.978 | 0.711 | 0.381 | 1/16"~1 1/2" | ASME B18.3 |
| #0 | Hexagon socket set screws with dog point | 0.318 | 1.27 | 0.762 | 0.305 | 0.978 | 0.711 | 0.381 | 1/16"~1 1/2" | ASME B18.3 |
| #0 | Hexagon socket set screws with cup point | 0.318 | 1.27 | 0.762 | 0.305 | 0.978 | 0.711 | 0.381 | 1/16"~1 1/2" | ASME B18.3 |
| #1 | Hexagon socket set screws with flat point | 0.397 | 1.524 | 0.927 | 0.371 | 1.194 | 0.889 | 0.483 | 1/16"~1 1/2" | ASME B18.3 |
| #1 | Hexagon socket set screws with cone point | 0.397 | 1.524 | 0.927 | 0.371 | 1.194 | 0.889 | 0.483 | 1/16"~1 1/2" | ASME B18.3 |
| #1 | Hexagon socket set screws with dog point | 0.397 | 1.524 | 0.927 | 0.371 | 1.194 | 0.889 | 0.483 | 1/16"~1 1/2" | ASME B18.3 |
| #1 | Hexagon socket set screws with cup point | 0.397 | 1.524 | 0.927 | 0.371 | 1.194 | 0.889 | 0.483 | 1/16"~1 1/2" | ASME B18.3 |
| #2 | Hexagon socket set screws with flat point | 0.454 | 1.524 | 1.092 | 0.437 | 1.397 | 0.889 | 0.559 | 1/16"~2 1/2" | ASME B18.3 |
| #2 | Hexagon socket set screws with cone point | 0.454 | 1.524 | 1.092 | 0.437 | 1.397 | 0.889 | 0.559 | 1/16"~2 1/2" | ASME B18.3 |
| #2 | Hexagon socket set screws with dog point | 0.454 | 1.524 | 1.092 | 0.437 | 1.397 | 0.889 | 0.559 | 1/16"~2 1/2" | ASME B18.3 |
| #2 | Hexagon socket set screws with cup point | 0.454 | 1.524 | 1.092 | 0.437 | 1.397 | 0.889 | 0.559 | 1/16"~2 1/2" | ASME B18.3 |
| #3 | Hexagon socket set screws with flat point | 0.529 | 1.778 | 1.257 | 0.503 | 1.626 | 1.27 | 0.635 | 1/8"~2 1/2" | ASME B18.3 |
| #3 | Hexagon socket set screws with cone point | 0.529 | 1.778 | 1.257 | 0.503 | 1.626 | 1.27 | 0.635 | 1/8"~2 1/2" | ASME B18.3 |
| #3 | Hexagon socket set screws with dog point | 0.529 | 1.778 | 1.257 | 0.503 | 1.626 | 1.27 | 0.635 | 1/8"~2 1/2" | ASME B18.3 |
| #3 | Hexagon socket set screws with cup point | 0.529 | 1.778 | 1.257 | 0.503 | 1.626 | 1.27 | 0.635 | 1/8"~2 1/2" | ASME B18.3 |
| #4 | Hexagon socket set screws with flat point | 0.635 | 1.778 | 1.422 | 0.569 | 1.841 | 1.27 | 0.711 | 1/8"~4" | ASME B18.3 |
| #4 | Hexagon socket set screws with cone point | 0.635 | 1.778 | 1.422 | 0.569 | 1.841 | 1.27 | 0.711 | 1/8"~4" | ASME B18.3 |
| #4 | Hexagon socket set screws with dog point | 0.635 | 1.778 | 1.422 | 0.569 | 1.841 | 1.27 | 0.711 | 1/8"~4" | ASME B18.3 |
| #4 | Hexagon socket set screws with cup point | 0.635 | 1.778 | 1.422 | 0.569 | 1.841 | 1.27 | 0.711 | 1/8"~4" | ASME B18.3 |
| #5 | Hexagon socket set screws with flat point | 0.635 | 2.032 | 1.575 | 0.635 | 2.045 | 1.575 | 0.762 | 3/16"~4" | ASME B18.3 |
| #5 | Hexagon socket set screws with cone point | 0.635 | 2.032 | 1.575 | 0.635 | 2.045 | 1.575 | 0.762 | 3/16"~4" | ASME B18.3 |
| #5 | Hexagon socket set screws with dog point | 0.635 | 2.032 | 1.575 | 0.635 | 2.045 | 1.575 | 0.762 | 3/16"~4" | ASME B18.3 |
| #5 | Hexagon socket set screws with cup point | 0.635 | 2.032 | 1.575 | 0.635 | 2.045 | 1.575 | 0.762 | 3/16"~4" | ASME B18.3 |
| #6 | Hexagon socket set screws with flat point | 0.794 | 2.032 | 1.753 | 0.701 | 2.273 | 1.575 | 0.889 | 1/8"~4" | ASME B18.3 |
| #6 | Hexagon socket set screws with cone point | 0.794 | 2.032 | 1.753 | 0.701 | 2.273 | 1.575 | 0.889 | 1/8"~4" | ASME B18.3 |
| #6 | Hexagon socket set screws with dog point | 0.794 | 2.032 | 1.753 | 0.701 | 2.273 | 1.575 | 0.889 | 1/8"~4" | ASME B18.3 |
| #6 | Hexagon socket set screws with cup point | 0.794 | 2.032 | 1.753 | 0.701 | 2.273 | 1.575 | 0.889 | 1/8"~4" | ASME B18.3 |
| #8 | Hexagon socket set screws with flat point | 0.794 | 2.286 | 2.07 | 0.833 | 2.692 | 1.981 | 1.016 | 1/8"~5" | ASME B18.3 |
| #8 | Hexagon socket set screws with cone point | 0.794 | 2.286 | 2.07 | 0.833 | 2.692 | 1.981 | 1.016 | 1/8"~5" | ASME B18.3 |
Dimensions are independent of the material: every size above is available in Property Class 8.8 Steel.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
Grade 8 8 Steel is one of the grades the catalog describes. Where the standard stops, the drawing takes over: fine pitches, left-hand threads, partial threading, and property classes above the catalogued grade where material and heat treatment allow. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

