ASME B18.6.2-2020 pdf free.Square Head Set Screws and Slotted Headless Set Screws (Inch Series).
2.2 Length 2.2.1 Measurement. The length of square head set screws shall be measured parallel to the axis of the screw from the intersection of the side of the head with the undersurface to the extreme point. 2.2.2 Length Tolerance. The length tolerance for square head setscrews shall be as shown in Table 2.2.2-1. 2.3 Threads 2.3.1 Thread Series and Class. The threads on square head set screws shall be Unified Inch coarse, fine, or 8- thread series, Class 2A, in accordance with ASME B1.1. For threads with additive finish, the size limits of Class 2A apply before coating, and the thread after coating is subject to acceptance using a basic Class 3A size GO thread gage and a Class 2A thread gage for either minimum material or NO GO. 2.3.2 Thread Gaging. Unless otherwise specified, dimensional acceptabilityofscrewthreads shall be deter- mined based on System 21, ASME B1.3.
2.5 Points 2.5.1 Point Types. When unspecified, square head set screws shall be supplied with cup points. Cup points may beknurled(internallyorexternally) atthemanufacturer’s option. Specifications forcone, dog, half-dog, flat, and oval points are in Table 2.5.1-1. 2.5.2 PointAngles. The external pointangles specified shall apply only to the portions ofthe point that lie below the thread root diameter, as angles within the thread profile may vary due to manufacturing processes. 2.5.3 Dog Points. When the length ofusable (effective) thread is less than the basic screw diameter, dog points shall not be used. Half-dog points shall be used for such screw lengths. 2.5.3.1 Point True Position. The axis of the dog or half-dog points shall be at true position with respect to the axis of the thread within a tolerance zone having a diameter of 0.010 in. for sizes up to and including 3 ∕ 4 (0.750) in. and a diameter of 0.020 in. for larger sizes, regardless of feature size.
2.7 Finishes Unless otherwise specified, bolts and screws shall be supplied with a plain (as-processed) finish, unplated or uncoated. Light oil on the surface is permissible to avoid corrosion during transportation, packaging, and further handling. If square head set screws are electro- plated, they shall be suitably treated to minimize hydrogen embrittlement. 2.8 Workmanship Square head setscrews shall be free from burrs, seams, laps, loose scale, and any other defects that could affect their serviceability. 2.9 Quality Assurance Manufacturers shall provide screws in accordance with ASME B18.18, Category 2.
2.10 Designation Square head set screws shall be designated by the following data, preferably in the sequence shown: product name; nominal size (number, fraction, or decimal equivalent); threads per inch; screw length (frac- tion or decimal equivalent); point style; material; protec- tive finish, if required. EXAMPLES: (1) Square Head Set Screw, ASME B18.6.2, 1 ∕ 4 — 20 × 3 ∕ 4 , Flat Point, Case-Hardened Steel, Zinc plated per ASTM F1941/ F1941M Fe/Zn 5C (2) Square Head Set Screw, ASME B18.6.2, 0.250 — 20 × 0.75, Cup Point, Through Hardened Steel, Zinc plated per ASTM F1941/F1941M Fe/Zn 3AN (3) Square Head Set Screw, ASME B18.6.2, 0.500 — 13 × 1.25, Cone Point, 303 Corrosion ResistantSteel, Hardness 70 – 95 HRB, Passivated per ASTM A380/A380MASME B18.6.2 pdf download.