Cold heading Service

ASME B18.6.3 Phillips Hex Collar Self Tapping Screws

ASME B18.6.3 Phillips Hex Collar Self-Tapping Screws combine a hexagonal head with an integrated collar and a Phillips cross recess. The hex head allows tightening with a wrench or socket, while the Phillips drive provides an additional option for screwdriver or power-driver installation. The collar extends the bearing area beneath the head, helping distribute pressure around the mounting hole. This design is suitable for sheet metal assemblies, brackets, and equipment components where a hexagonal head and a cross-recessed drive are useful.

Our production process focuses on the dimensional consistency of the hex head, collar, Phillips recess, and tapping thread. Cold heading forms the head and collar, while thread rolling produces the specified thread profile. The cross recess is formed during cold heading rather than machined. We also control material selection, heat treatment, and surface finishing according to order requirements, with dimensional checks to verify critical features against the applicable specifications.

ASME B18.6.3 Phillips Hex Collar Self Tapping Screws Stainless Steel

Specification:

Item	Specification
Standard	ASME B18.6.3
Product Type	Phillips Hex Collar Self Tapping Screws
Thread Diameter	#4-3/8"
Point Type	Type AB Pointed Tip
Material	Carbon Steel, Stainless Steel
Steel Property	SAE J933
Stainless Steel Property	ISO 3506-4
Surface Treatment	Black Oxidation,Zinc Plated,Bright Finish
Inspection	Dimensions,Thread,Hardness,Coating

Dimension Chart:

Drawing of ASME B18.6.3 Phillips Hex Collar Self Tapping Screws

Mon	#4	#5	#7	#8	#10	#12	1/4	5/16	3/8
P	24	20	19	18	16	14	14	12	12
s max	0.188	0.188	0.25	0.25	0.312	0.312	0.375	0.5	0.562
s min	0.181	0.181	0.244	0.244	0.305	0.305	0.367	0.489	0.551
e min	0.202	0.202	0.272	0.272	0.34	0.34	0.409	0.545	0.614
k max	0.06	0.07	0.093	0.11	0.12	0.155	0.19	0.23	0.295
k min	0.049	0.058	0.08	0.096	0.105	0.139	0.172	0.208	0.27
dc max	0.243	0.26	0.328	0.348	0.414	0.432	0.52	0.676	0.78
dc min	0.225	0.24	0.302	0.322	0.384	0.398	0.48	0.624	0.72
h max	0.019	0.025	0.029	0.031	0.031	0.039	0.05	0.055	0.063
h min	0.011	0.015	0.017	0.019	0.019	0.022	0.03	0.035	0.037
M	0.097	0.105	0.148	0.168	0.178	0.247	0.277	0.358	0.386
No.	1	1	2	2	2	3	3	4	4
t max	0.067	0.076	0.089	0.115	0.127	0.152	0.186	0.234	0.267
t min	0.049	0.058	0.064	0.09	0.102	0.127	0.161	0.219	0.243
d max	0.114	0.13	0.154	0.166	0.189	0.215	0.246	0.315	0.38
d min	0.108	0.123	0.147	0.159	0.182	0.208	0.237	0.306	0.371
d1 max	0.086	0.094	0.115	0.122	0.141	0.164	0.192	0.244	0.309
d1 min	0.082	0.09	0.109	0.116	0.135	0.157	0.185	0.236	0.299

Mechanical Property:

ASME B18.6.3 Phillips hex collar self-tapping screws must withstand installation torque while maintaining the integrity of the Phillips recess, hex head, collar, and tapping thread. The hex head allows wrench or socket tightening, while the Phillips recess accommodates a matching driver. The collar provides a bearing surface beneath the head, and the tapping thread must remain intact as it forms a mating thread in the workpiece.

Carbon Steel – SAE J933

SAE J933 specifies mechanical and quality requirements for applicable steel tapping screws, including torsional strength. This property is important for preventing screw breakage during installation. The required performance depends on the screw type and size.

Stainless Steel – ISO 3506-4

ISO 3506-4 specifies mechanical and physical requirements for stainless steel tapping screws, including hardness, thread-forming ability, and torsional strength. These properties help ensure that the screw can form a mating thread without excessive thread deformation or breakage during installation. The applicable requirements depend on the stainless steel grade, hardness class, and screw size.

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