ASME B18.3 Cup Point Socket Set Screw
ASME B18.3 cup point socket set screws feature a concave tip with a circular contact edge and an internal hex drive for installation in threaded holes. The cup-shaped end is designed to grip the mating surface, helping resist loosening and movement under suitable installation conditions. These screws are commonly used to secure components on shafts, hold parts in position, and maintain alignment in mechanical assemblies.
We supply cup point socket set screws in alloy steel and other available materials, with different thread sizes, lengths, and surface finishes to meet various application requirements. Our production processes include cold heading, thread rolling, and dimensional inspection to support consistent thread accuracy and product quality.


Specification:
| Item | Specification |
|---|---|
| Standard | ASME B18.3 |
| Product Type | Cup Point Socket Set Screw |
| Drive Type | Hex Socket |
| Point Tppe | Cup Point |
| Thread Standard | ASME B1.1 Unified Inch Screw Threads |
| Thread | UNC,UNF |
| Thread Tolerance | 2A |
| Size Range | #0-2" |
| Surface Treatment | Black Oxidation,Zinc Plated,Bright Finish,Passivation |
| Mechanical Property(Steel) | ASTM F912 |
| Mechanical Property(Stainless Steel) | ASTM F880 |
- RELATED SCREWS:
- SET SCREWS
- ASME B18.3 Flat Point Set Screws
- ASME B18.3 Oval Point Socket Set Screws
- ASME B18.3 Cone Point Set Socket Screws
- ASME B18.3 Half Dog Point Spline Socket Set Screws
- DIN913 Flat Point Set Screws
- DIN914 Cone Point Set Screws
- DIN915 Dog Point Set Screws
- DIN916 Cup point Socket Set Screws
Dimension Chart of ASME B18.3 Cup Point Socket Set Screw:

| Mon | #0 | #1 | #2 | #3 | #4 | #5 | #6 | #8 | #10 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 | 7/8 | 1 | 1-1/8 | 1-1/4 | 1-3/8 | 1-1/2 | 1-3/4 | 2 |
| P | 80 | 64 | 56 | 48 | 40 | 40 | 32 | 32 | 24 | 20 | 18 | 16 | 14 | 13 | 11 | 10 | 9 | 8 | 7 | 7 | 6|8 | 6|8 | 5|8 | 4.5 |
| s | 0.028 | 0.035 | 0.035 | 0.05 | 0.05 | 0.062 | 0.062 | 0.078 | 0.094 | 0.125 | 0.156 | 0.188 | 0.219 | 0.25 | 0.312 | 0.375 | 0.5 | 0.562 | 0.562 | 0.625 | 0.625 | 0.75 | 1 | 1 |
| t min | 0.05 | 0.06 | 0.06 | 0.07 | 0.07 | 0.08 | 0.08 | 0.09 | 0.1 | 0.125 | 0.156 | 0.188 | 0.219 | 0.25 | 0.312 | 0.375 | 0.5 | 0.562 | 0.562 | 0.625 | 0.625 | 0.75 | 1 | 1 |
| dz max | 0.033 | 0.04 | 0.047 | 0.054 | 0.061 | 0.067 | 0.074 | 0.087 | 0.102 | 0.132 | 0.172 | 0.212 | 0.252 | 0.291 | 0.371 | 0.45 | 0.53 | 0.609 | 0.689 | 0.767 | 0.848 | 0.926 | 1.086 | 1.244 |
| dz min | 0.027 | 0.033 | 0.039 | 0.045 | 0.051 | 0.057 | 0.064 | 0.076 | 0.088 | 0.118 | 0.156 | 0.194 | 0.232 | 0.27 | 0.347 | 0.425 | 0.502 | 0.579 | 0.655 | 0.733 | 0.808 | 0.886 | 1.039 | 1.193 |
Mechanical Property:
ASTM F912 — Alloy Steel Cup Point Socket Set Screws
ASTM F912 specifies quenched and tempered alloy steel socket set screws with a hardness of 45–53 HRC, corresponding to property class 45H under ISO 898-5. The specification is intended for set screws used in compression applications and includes requirements for material analysis, torsional strength, and surface quality. These criteria provide a basis for checking the consistency of heat-treated alloy steel screws and their suitability for the intended loading conditions.
ASTM F880 — Stainless Steel Cup Point Socket Set Screws
ASTM F880 covers austenitic stainless steel socket set screws. Unlike the alloy steel specification, its requirements include verification of stainless steel composition, torque performance, Vickers hardness, and corrosion resistance. The screws are supplied in solution-annealed or cold-worked conditions, as applicable, with the selected material and condition determining the relevant requirements.
