Socket Set Screws: Sizes - Dimensions & Specifications

Name: AFT Fasteners
Telephone: 877-844-8595

Labeled Diagrams of Socket Set Screws

Socket Set Screw Dimensions (Alloy Steel) ASME B18.3-2003
Nominal Size** Click on the size to shop products	Key Engage-ment (K)	Cup & Flat Point Diameter (F)		Oval Point Radius (R)	*Cone Point Angle (A)**	Half Dog Point
	Key Engage-ment (K)	Cup & Flat Point Diameter (F)		Oval Point Radius (R)		Diameter (D)		Length (H)
	Min	Max	Min	Basic		Max	Min	Max	Min
0	0.050	0.033	0.027	0.045	0.09	0.040	0.037	0.017	0.013
1	0.060	0.040	0.033	0.055	0.09	0.049	0.045	0.021	0.017
2	0.060	0.047	0.039	0.064	0.13	0.057	0.053	0.024	0.020
3	0.070	0.054	0.045	0.074	0.13	0.066	0.062	0.027	0.023
4	0.070	0.061	0.051	0.084	0.19	0.075	0.070	0.030	0.026
5	0.080	0.067	0.057	0.094	0.19	0.083	0.078	0.033	0.027
6	0.080	0.074	0.064	0.104	0.19	0.092	0.087	0.038	0.032
8	0.090	0.087	0.076	0.123	0.25	0.109	0.103	0.043	0.037
10	0.100	0.102	0.088	0.142	0.25	0.127	0.120	0.049	0.041
1/4	0.125	0.132	0.118	0.188	0.31	0.156	0.149	0.067	0.059
5/16	0.156	0.172	0.156	0.234	0.38	0.203	0.195	0.082	0.074
3/8	0.188	0.212	0.194	0.281	0.44	0.250	0.241	0.099	0.089
7/16	0.219	0.252	0.232	0.328	0.50	0.297	0.287	0.114	0.104
1/2	0.250	0.291	0.270	0.375	0.57	0.344	0.334	0.130	0.120
5/8	0.312	0.371	0.347	0.469	0.75	0.469	0.456	0.164	0.148
3/4	0.375	0.450	0.425	0.562	0.88	0.562	0.549	0.196	0.180
7/8	0.500	0.530	0.502	0.656	1.00	0.656	0.642	0.227	0.211
1	0.562	0.609	0.579	0.750	1.13	0.750	0.734	0.260	0.240

*Angle is 90-degrees (+/-2 degrees) for these lengths and over, and it is 118-degress (+/-2 degrees) for shorter lengths.

** Click on the Nominal Size to shop for products.

Socket Set Screws : Nominal Screw Length
Tolerance on Length	Nominal Screw Length
	Up to 0.63" (Inclusive)	Over 0.63" - 2" (Inclusive)	Over 2" - 6"
	+/-0.01	+/-0.02	+/-0.03

Socket Set Screws (Alloy Steel)ASME B18.3-2003
Nominal Size Click on the size to shop products	Shortest Nominal Length to Which Column A Applies			Hex Key Size (S)	Tightening Torque (inch/lbs.)
Nominal Size Click on the size to shop products	Cup & Flat Point	Cone & Oval Point	Half Dog Point	Hex Key Size (S)	Tightening Torque (inch/lbs.)
0	0.13	0.13	0.13	0.028	0.86
1	0.13	0.19	0.13	0.028	0.86
2	0.13	0.19	0.19	0.035	1.8
3	0.19	0.19	0.19	0.050	5
4	0.19	0.19	0.19	0.050	5
5	0.19	0.19	0.19	1/16	9.5
6	0.19	0.25	0.19	1/16	9.5
8	0.19	0.25	0.25	5/64	19.4
10	0.19	0.25	0.25	3/32	33.5
1/4	0.25	0.31	0.31	1/8	77.9
5/16	0.31	0.44	0.38	5/32	156
3/8	0.38	0.44	0.44	3/16	273
7/16	0.44	0.63	0.50	7/32	428
1/2	0.50	0.63	0.63	1/4	615
5/8	0.63	0.88	0.88	5/16	1315
3/4	0.75	1.00	1.00	3/8	2150
7/8	0.8	1.00	1.00	1/2	5130
1	1.00	1.25	1.25	9/16	7010

Socket Set Screws Mechanical Properties ASME B18.3-2003
	Cup Point	Half-Dog Point	Oval Point	Flat Point	Cone Point
Description	Fully threaded, headless screw with a hexagonal drive at one end and a cup-shaped indentation at the other.	Fully-threaded, headless screw with a hex drive at one end and a protruding tip with a flat surface at the opposing end.	Possesses an oval-shaped point on the end opposing the flush hex drive.	Possesses a flat surface at the end opposing the hexagonal drive.	Has a short conical-shaped point at the opposite end from the hexagonal drive.
Applications/ Advantages	Most used style Designed for fast, permanent and semi-permanent location of parts on shafts with a hardness differential of 10-15 Rockwell C points and where cutting in of the cup edge on the shaft is acceptable.	For permanent setting - often used instead of a dowel pin. The point should closely fit the diameter of the drilled hole, or alternatively, against the flat.	The preferred style for frequent re-set on soft or hard shafts with minimum deforming. Often used for permanent setting on shafts that are spotted, splined or grooved, and for applications where the point meets the shaft on an angle. Sometimes substituted for the cup point style.	Designed for frequent re-setting or re-locating on hard steel shafts and where minimal damage is shafts is essential. Ground flats on the shaft improves the contacts.	Designed for permanent setting on soft or hardened shafts. Deep penetration gives this style of screw the highest torsional and axial holding power. Can be used as a hangar or pivot. For shafts of Rockwell hardness C15 or more, spot point half its depth.
Material	Made from alloy steel with a chemical composition of: 0.28 to 0.50% Carbon, 0.040% (max) Phosphorus, and 0.045% (max) Sulfur. Also, chromium, nickel, molybdenum or vanadium should be present in a quantity sufficient to meet the strength requirements outlined below.
Heat Treatment	Set screws should be heat treated via oil quenching from above the transformation temperature and then tempered at a temperature that is conducive to meeting the hardness requirements.
Hardness	Rockwell C45 - 53
Torsional Strength	Socket set screws of sufficient length should be tested to determine if that can withstand the application of the test torque outlined in the above table without evidence of the socket reaming or the screw bursting.
Finish	Black Thermal Finish