4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) 4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) (pack of 1)

Accu Product Code (APC): SSCA-4-40-1/2-A2-BL

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4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) 4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) (pack of 1)

Accu Product Code (APC): SSCA-4-40-1/2-A2-BL

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Certified Precision - Certificate of Conformity Supplied As Standard.
Manufactured in the UK.
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Accu Product Code (APC): SSCA-4-40-1/2-A2-BL
Thread Size: 4-40 UNC
Length (L): 1/2 inch
Head Diameter (D): 0.183 inch Tolerance: +0/-0.007 inch
Material: Stainless Steel - (A2)
Finish: Matte Black
Captive Diameter (C): 0.077 inch
Captive Length: 0.276 inch
Head Height (H): 0.112 inch Tolerance: +0/-0.004 inch
Hexagon Depth (P): 0.051 inch
Manufacturing Standard: ASME B18.3
Material Family: Stainless Steel
Socket Size (J): 3/32 inch
System of Measurement: Imperial
Thread Length (E): 0.224 inch
Thread Pitch: 40 TPI
Weight per 100 Units: 75 g

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4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) Description

The 4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) has the following features:

Captive Diameter (C): 0.077 inch
Captive Length: 0.276 inch
Matte Black Finish
Head Diameter (D): 0.183 inch
Head Diameter (D) Tolerance: +0/-0.007 inch
Head Height (H): 0.112 inch
Head Height (H) Tolerance: +0/-0.004 inch
Hexagon Depth (P): 0.051 inch
Length (L): 1/2 inch
Manufacturing Standard: ASME B18.3
Stainless Steel - (A2)
Stainless Steel Material Family
Socket Size (J): 3/32 inch
System of Measurement: Imperial
Thread Length (E): 0.224 inch
Thread Pitch: 40 TPI
Thread Size: 4-40 UNC

Discover more about the Imperial Socket Cap Head Captive Screws range.

Imperial socket cap head captive screws are precision fasteners designed according to imperial measurements. Featuring a cap head with a hexagonal socket drive, they allow for high torque and secure fastening. The captive screw design ensures the screw remains attached to a panel or assembly even when loosened, enhancing safety and preventing loss of components in sensitive environments. This is achieved through an unthreaded section beneath the head that meets industry standards for captive hardware.

How Imperial Socket Cap Head Captive Screws Work

These screws are essential in applications requiring frequent assembly and disassembly, such as machinery maintenance, aerospace equipment and electronics enclosures. For instance, in industrial machinery, captive screws prevent loss during maintenance, allowing personnel to access internal components without misplacing fasteners as they can be loosened yet still stay attached to the panel. The hex socket drive enables precise tightening with an Allen key, ensuring consistent torque and reducing the risk of over-tightening that could damage threads or components.

Materials Imperial Socket Cap Head Captive Screws Are Made From

Our imperial cap head captive screws are crafted from high-quality A2 and A4 stainless steel. A2 offers excellent corrosion resistance, ideal for general indoor applications. A4, or marine-grade stainless steel, provides superior resistance to chemicals and saltwater, making it perfect for marine, chemical processing and outdoor use. Selecting the appropriate material ensures longevity and reliability in specific environments.

Size and Type Imperial Socket Cap Head Captive Screws Available

Accu offers a wide range of sizes to meet various engineering needs, with thread sizes from 0-80 UNF to 1"-8 UNC and lengths from 1/4" to 12". Each screw features a cap head design with a hex socket drive for ease of use and consistent torque application. Along with the standard untreated finish, we also offer specialist finishes are available such as AccuBlack chemical blackeneing which provides a sleek matte black appearance for aesthetic purposes or to reduce reflections in sensetive equipment. We also offer AccuLock thread locking patches pre-appled which prevents loosening due to vibration, essential for machinery and automotive uses.

In addition to imperial sizes, we also offer metric socket cap head captive screws for projects requiring metric measurements.

Shipping Information

Shipping Destinations:

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Weight (100 items):

0.075kg

Component History

Product First Available:

Thursday, August 20, 2015

Stock Last Updated:

11:23 PMWednesday, June 3, 2026

Specification Last Updated:

Wednesday, June 3, 2026

Barcodes

APC (Accu Product Code):

SSCA-4-40-1/2-A2-BL

EAN13 (International Article No.):

5057196493135

ASIN (Amazon Stock Identification No.):

ASIN not defined.

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Thread Size

Length (L)

Head Diameter (D)

Material

Finish

Captive Diameter (C)

Captive Length

Head Height (H)

Hexagon Depth (P)

Manufacturing Standard

Material Family

Socket Size (J)

System of Measurement

Thread Length (E)

Thread Pitch

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4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) 4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) (pack of 1)

4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) 4-40 UNC x 1/2 Inch Imperial Socket Cap Head Captive Screws (ASME B18.3) - Black Stainless Steel - (A2) (pack of 1)

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