Cold Headers
Cold Headers
5514 N. Elston Ave
Chicago, IL 60630
Phone: 1-773-775-7900
Fax: 1-773-775-0779
Email: sales@coldheaders.com
Website: www.coldheaders.com
Working Hours: Mon - Fri 8:00am - 4:30pm CST
Saturday - Sunday CLOSED If you have any questions, please call or email us.
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Alloy Steel Flat Head Socket Cap Screws

Alloy steel flat head socket cap screws are designed for countersunk assemblies where the screw head must sit flush with, or close to, the surrounding mounting surface. Their 82° countersunk head geometry reduces surface projection while the internal hex socket provides controlled installation with a hex key.

These fasteners are commonly used in machine guarding, tooling plates, fixtures, access panels, robotics, automation equipment, conveyor systems, packaging machinery, equipment covers, brackets, enclosures, and precision mechanical assemblies. A flush-mounted head can help reduce interference with moving components, improve clearance around adjacent parts, limit snag points, and create a cleaner finished surface.

Cold Headers supplies alloy steel flat head socket cap screws in a broad range of inch thread sizes and lengths, including uncommon and difficult-to-source configurations. Individual product pages provide exact thread size, overall length, nominal body diameter, head diameter, hex socket size, key engagement, and other verified dimensional information where available. Review the listed dimensions carefully to confirm compatibility with the tapped hole, countersink, surrounding components, and installation tooling.

Why Use an Alloy Steel Flat Head Socket Cap Screw?

  • Flush installation: The countersunk head is intended to sit within a properly prepared 82° countersink.
  • Reduced surface projection: Helps improve clearance around panels, guards, covers, tooling, and moving assemblies.
  • Internal hex drive: Allows installation with a hex key where external wrench clearance is limited.
  • Broad industrial use: Suitable for machinery, fixtures, automation systems, brackets, enclosures, and maintenance repairs.
  • Exact-size selection: Product pages allow engineers and purchasers to compare thread, length, body, head, and socket dimensions.

Selecting the Correct Flat Head Socket Cap Screw

Begin by confirming the required thread size and overall screw length. Then review the head diameter and countersink requirements to ensure the head seats properly without excessive projection or over-travel. The hex socket size should match the intended installation tool, while body diameter and key engagement can help confirm fit and drive access. Flat head socket cap screws should be selected for assemblies specifically designed with the appropriate countersunk geometry.

Cold Headers Inc. has supplied specialty industrial socket fasteners since 1962. Our catalog is structured to help engineers, distributors, maintenance teams, and purchasing professionals locate exact sizes, uncommon lengths, and difficult-to-find socket products without unsupported inventory claims.

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.

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Unit of Measure
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Item #

Item Name

Diameter

Length

Material

Quantity

List Price (per 100 pieces)

Basic Diameter

Maximum Head Diameter

Minimum Head Diameter

Hex Socket Size

Minimum Key Engagement

FHCS-AS 4-48 x 1 N/A 4-48 x 1 Alloy Steel Flat Head Socket Cap Screw N/A 4-48 N/A 1 in N/A Alloy Steel N/A 100 $19.00 N/A 0.112 in N/A 0.255 in N/A 0.218 in N/A 1/16 in N/A 0.055 in
FHCS-AS 4-48 x 1 1/4 N/A 4-48 x 1 1/4 Alloy Steel Flat Head Socket Cap Screw N/A 4-48 N/A 1 1/4 in N/A Alloy Steel N/A 100 Call or Email for Pricing N/A 0.112 in N/A 0.255 in N/A 0.218 in N/A 1/16 in N/A 0.055 in
FHCS-AS 4-48 x 1 1/2 N/A 4-48 x 1 1/2 Alloy Steel Flat Head Socket Cap Screw N/A 4-48 N/A 1 1/2 in N/A Alloy Steel N/A 100 Call or Email for Pricing N/A 0.112 in N/A 0.255 in N/A 0.218 in N/A 1/16 in N/A 0.055 in
FHCS-AS 5-40 x 1/8 N/A 5-40 x 1/8 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 1/8 in N/A Alloy Steel N/A 100 $24.00 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 3/16 N/A 5-40 x 3/16 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 3/16 in N/A Alloy Steel N/A 100 $10.00 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 1/4 N/A 5-40 x 1/4 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 1/4 in N/A Alloy Steel N/A 100 $3.43 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 5/16 N/A 5-40 x 5/16 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 5/16 in N/A Alloy Steel N/A 100 $5.50 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 3/8 N/A 5-40 x 3/8 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 3/8 in N/A Alloy Steel N/A 100 $3.55 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 7/16 N/A 5-40 x 7/16 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 7/16 in N/A Alloy Steel N/A 100 $10.00 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 1/2 N/A 5-40 x 1/2 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 1/2 in N/A Alloy Steel N/A 100 $3.66 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 5/8 N/A 5-40 x 5/8 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 5/8 in N/A Alloy Steel N/A 100 $3.76 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 3/4 N/A 5-40 x 3/4 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 3/4 in N/A Alloy Steel N/A 100 $3.87 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 7/8 N/A 5-40 x 7/8 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 7/8 in N/A Alloy Steel N/A 100 $12.00 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 1 N/A 5-40 x 1 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 1 in N/A Alloy Steel N/A 100 $12.50 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 1 1/4 N/A 5-40 x 1 1/4 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 1 1/4 in N/A Alloy Steel N/A 100 $15.00 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 5-40 x 1 1/2 N/A 5-40 x 1 1/2 Alloy Steel Flat Head Socket Cap Screw N/A 5-40 N/A 1 1/2 in N/A Alloy Steel N/A 100 $20.00 N/A 0.125 in N/A 0.281 in N/A 0.240 in N/A 5/64 in N/A
FHCS-AS 6-32 x 1/8 N/A 6-32 x 1/8 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 1/8 in N/A Alloy Steel N/A 100 $59.00 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
FHCS-AS 6-32 x 3/16 N/A 6-32 x 3/16 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 3/16 in N/A Alloy Steel N/A 100 $12.00 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
FHCS-AS 6-32 x 1/4 N/A 6-32 x 1/4 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 1/4 in N/A Alloy Steel N/A 100 $2.45 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
FHCS-AS 6-32 x 5/16 N/A 6-32 x 5/16 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 5/16 in N/A Alloy Steel N/A 100 $3.50 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
FHCS-AS 6-32 x 3/8 N/A 6-32 x 3/8 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 3/8 in N/A Alloy Steel N/A 100 $2.50 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
FHCS-AS 6-32 x 7/16 N/A 6-32 x 7/16 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 7/16 in N/A Alloy Steel N/A 100 $4.00 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
FHCS-AS 6-32 x 1/2 N/A 6-32 x 1/2 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 1/2 in N/A Alloy Steel N/A 100 $2.55 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
FHCS-AS 6-32 x 5/8 N/A 6-32 x 5/8 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 5/8 in N/A Alloy Steel N/A 100 $2.60 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
FHCS-AS 6-32 x 3/4 N/A 6-32 x 3/4 Alloy Steel Flat Head Socket Cap Screw N/A 6-32 N/A 3/4 in N/A Alloy Steel N/A 100 $2.77 N/A 0.138 in N/A 0.307 in N/A 0.263 in N/A 5/64 in N/A 0.066 in
Unit of Measure
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