ASME B18.6.3 Slotted 80° Countersunk Head Self Tapping Screw

ASME B18.6.3 sets dimensional standards for inch-series slotted 80° countersunk self-tapping screws. This standard defines all critical geometric controls such as head diameter, slot width and depth, thread pitch, shank diameter and 45° point angle. The 80-degree countersunk head sits flush with the workpiece surface after installation, ideal for applications where a low-profile, smooth finish is required.

These slotted countersunk tapping screws create mating threads directly in pre-drilled materials during driving. They are widely specified across automotive, electrical equipment and general fabrication projects. Our technical page provides engineering drawings and size tolerance data to support part selection, inspection and quality verification for your fastener sourcing.

ASME B18.6.3 Slotted 80° Countersunk Head Self Tapping Screw Stainless Steel

ASME B18.6.3 Slotted 80° Countersunk Head Self Tapping Screw Steel

Specification:

Item	Specification
Standard	ASME B18.6.3
Product Type	Slotted 80° Countersunk Head Self Tapping Screw
Thread Diameter	#0-5/16"
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 Slotted 80° Countersunk Head Self Tapping Screw

Mon	#0	#1	#2	#3	#4	#5	#6	#7	#8	#10	#12	1/4	5/16
P	48	42	32	28	24	20	20	19	18	16	14	14	12
dk max	0.112	0.137	0.162	0.187	0.212	0.237	0.262	0.287	0.312	0.362	0.412	0.477	0.597
dk min	0.096	0.12	0.144	0.167	0.191	0.215	0.238	0.262	0.285	0.333	0.38	0.442	0.556
k	0.035	0.043	0.051	0.059	0.067	0.075	0.083	0.091	0.1	0.116	0.132	0.153	0.191
n max	0.023	0.026	0.031	0.035	0.039	0.043	0.048	0.048	0.054	0.06	0.067	0.075	0.084
n min	0.016	0.019	0.023	0.027	0.031	0.035	0.039	0.039	0.045	0.05	0.056	0.064	0.072
t max	0.015	0.019	0.023	0.027	0.03	0.034	0.038	0.041	0.045	0.053	0.06	0.07	0.088
t min	0.01	0.012	0.015	0.017	0.02	0.022	0.024	0.027	0.029	0.034	0.039	0.046	0.058
d max	0.06	0.075	0.088	0.101	0.114	0.13	0.139	0.154	0.166	0.189	0.215	0.246	0.315
d min	0.054	0.069	0.082	0.095	0.108	0.123	0.132	0.147	0.159	0.182	0.208	0.237	0.306
d1 max	0.036	0.049	0.064	0.075	0.086	0.094	0.104	0.115	0.122	0.141	0.164	0.192	0.244
d1 min	0.033	0.046	0.06	0.071	0.082	0.09	0.099	0.109	0.116	0.135	0.157	0.185	0.236

Mechanical Property:

SAE J933 Carbon Steel Self-Tapping Screws

For carbon steel slotted 80° countersunk self-tapping screws to ASME B18.6.3, mechanical performance shall comply with SAE J933. This standard regulates material chemical composition, temper surface hardness, core hardness, microstructure and minimum torsional failure torque. Controlled hardenability ensures the tapping screw can form internal threads without stripping or fracturing under specified installation torque. SAE J933 explicitly excludes stainless steel fasteners.

ISO 3506-4 Stainless Steel Self-Tapping Screws

When this same 80° countersunk slotted tapping screw is manufactured from corrosion-resistant stainless steel, mechanical acceptance follows ISO 3506-4. It specifies hardness limits and minimum torsional strength for austenitic, ferritic and martensitic stainless grades. ISO 3506-4 is the globally recognized performance standard for stainless tapping screws, paired with ASME B18.6.3 for inch-series dimensional requirements.

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