1/4-20 Button Head Screw Dimensions & 1/4-20 Socket Head | Supplier

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🔩 Precision-Driven 1/4-20 Button Head & Socket Head Screws: Standardized Dimensions, Uncompromising Quality

Are you tired of inconsistent 1/4-20 button head screw dimensions causing assembly failures and costly downtime? As a global supplier, Boen Fastener delivers ASME B18.3-compliant 1/4-20 socket head cap screws and button heads with factory-direct pricing, rigorous quality control, and high-speed delivery to the USA, Europe, and beyond.

🚀 Get Free Quote & Sample Kit in 24 Hours

✓ No minimum order restrictions for first trial

⚠️ The Hidden Cost of Inconsistent Fastener Specifications

📐 The “1/4-20 Headache”

A 0.005-inch variance in head height or hex socket depth can cause tool slip, cam-out, and joint failure. Many suppliers fail to provide certified 1/4-20 button head screw dimensions, leading to rework and rejected shipments.

💰 Budget vs. Reliability

High shipping costs + low-quality materials = inflated TCO. Industry data shows that 37% of mechanical failures in assembly are linked to substandard fasteners. “Cheap” often leads to expensive production line stoppages.

🌍 Global Supply Chain Risks

Unreliable lead times and poor communication from offshore suppliers create bottlenecks. You need a partner with documented quality control, real-time inventory visibility, and fast logistics.

🔧 Tooling Incompatibility

Non-standard 1/4-20 socket head screw dimensions or button head profiles can strip tooling. This increases maintenance costs and slows down your assembly lines.

✅ Precision Engineering: Decoding 1/4-20 Button Head & Socket Head Dimensions

At Boen Fastener, we manufacture every 1/4-20 button head screw and 1/4-20 socket head cap screw to strict ASME B18.3 / ISO 898 standards. Our in-house lab ensures 100% dimensional consistency across every batch.

📏 1/4-20 Button Head Screw Dimensions (ASME B18.3)

Specification	Imperial	Metric
Thread Size	1/4-20 UNC	M6 x 1.27
Head Diameter (A)	0.437 in	11.1 mm
Head Height (H)	0.132 in	3.35 mm
Key Hex Size (Socket Depth)	1/8 in	3.18 mm
Tensile Strength (Grade 8)	150,000 psi	1034 MPa
Available Materials	Alloy Steel (8.8/10.9/12.9), 304 SS, 316 SS, Brass
Standard Finishes	Plain, Black Oxide, Zinc Plated (RoHS), HDG, Dacromet

✅ Available in custom lengths from 1/4″ to 4″.

🔩 1/4-20 Socket Head Cap Screw Dimensions (ASME B18.3)

Specification	Imperial	Metric
Thread Size	1/4-20 UNC	M6 x 1.27
Head Diameter (A)	0.375 in	9.53 mm
Head Height (H)	0.250 in	6.35 mm
Key Hex Size	3/16 in	4.76 mm
Tensile Strength (Grade 8)	150,000 psi	1034 MPa
Available Materials	Alloy Steel (8.8/10.9/12.9), 304 SS, 316 SS, 17-4 PH
Standard Finishes	Plain, Black Oxide, Phosphate, Zinc Nickel, PTFE

✅ Custom heat treatment and surface coating available for extreme environments.

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Powerful Factory

30+ production lines, 5000+ tons annual output. Full in-house R&D and tooling.

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Quality Assurance

ISO 9001 certified. 100% dimensional inspection, hardness testing, and salt spray testing.

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High-Speed Delivery

Stock program for standard sizes. Ship within 7 days. Air freight and sea freight options.

🔍 Need custom lengths or special coatings for your 1/4-20 button head screws or socket head screws? Our OEM/ODM team provides tailored solutions with fast turnaround. Request a custom quote

🌍 Trusted by Global OEMs & Industrial Leaders

+ 26 other global partners

“We switched to Boen for our 1/4-20 socket head cap screws. The dimensional consistency is perfect. We eliminated 98% of our cam-out issues. Their quality control is world-class.”

– John M. Purchasing Manager, US Automotive Tier 1

“Excellent supplier for 1/4-20 button head screws. Fast delivery, great pricing, and they provide full material certifications. Highly recommended for European MRO operations.”

– Anna K. Operations Director, German Industrial Equipment

❓ Frequently Asked Questions About 1/4-20 Fasteners

❔ What is the difference between a button head and a socket head cap screw?

A button head screw has a lower profile (0.132 in height) and a larger diameter head (0.437 in), making it ideal for limited clearance applications. A socket head cap screw has a taller cylindrical head (0.250 in height) designed for higher torque applications and deeper socket engagement.

❔ What are the exact 1/4-20 button head screw dimensions?

Per ASME B18.3: Head Diameter = 0.437 in (11.1 mm), Head Height = 0.132 in (3.35 mm), Hex Socket Size = 1/8 in (3.18 mm). We provide a full dimensional inspection report with every shipment.

❔ What are the exact 1/4-20 socket head screw dimensions?

Per ASME B18.3: Head Diameter = 0.375 in (9.53 mm), Head Height = 0.250 in (6.35 mm), Hex Socket Size = 3/16 in (4.76 mm). All dimensions are held to tight tolerances for reliable tooling fit.

❔ What grade of steel is best for high-stress applications?

For high-stress environments, we recommend Grade 8 (12.9) alloy steel with a tensile strength of 150,000 psi. For corrosive environments, 316 stainless steel offers excellent resistance. Our team can help you select the optimal material.

❔ Can you provide custom lengths or coatings for 1/4-20 screws?

Absolutely. Our OEM/ODM service supports custom lengths from 1/4″ to 4″, special head markings, and coatings like Xylan, PTFE, Dacromet, and Zinc Nickel. Minimum order quantity is flexible for trial orders.

❔ How do you ensure quality and consistency?

We follow a 3-stage QC process: incoming raw material testing (chemical composition & hardness), in-process dimensional inspection, and final random sampling (ANSI/ASQ Z1.4). We also provide full traceability with heat numbers and mill certificates.

❔ What are your shipping terms and lead times to the USA/Europe?

We offer EXW, FOB, CIF, and DDP terms. Standard lead time is 15-25 days for bulk orders. Express shipping (DHL/FedEx) takes 3-5 days. We have dedicated logistics partners for smooth customs clearance.

✍️ About the Author

Ethan Chen – Senior Mechanical Engineer & Fastening Specialist

🔧 15+ years in industrial fastener manufacturing and export. Specializing in ASME/ISO standard fasteners, material science, and supply chain optimization for global OEMs.

“We sourced 1/4-20 button head screws from Boen for a critical aerospace jig. The tolerances were spot on, and the documentation was impeccable. A reliable partner.”