Is 1/4 inch the right length for my application?

A 1/4" (6.35mm) screw is typically suitable for fastening materials that are 1/8" to 3/16" thick, leaving adequate thread engagement in the mating material. For countersunk applications, account for the depth of the countersink so the head sits flush. If your material is thicker, a longer #2-56 screw may be needed.

2 - 56 UNC Phillips Flat Head Countersunk Machine Screws, 1/4" — Carbon Steel, Bright Nickel - HomeDIYer

Roll over image to zoom in Click on image to zoom

2-56 UNC Phillips Flat Head Countersunk Machine Screws, 1/4" — Carbon Steel, Bright Nickel

HomeDIYer

No reviews

By HomeDIYer®

Material: Carbon Steel / Bright Nickel

Thread Diameter x Length: 2-56 X 1/4"

Amount: 100 PCS

Price:

$4.94 USD

Stock:

In stock (500 units), ready to be shipped

Quantity:

Share this product

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

DIY Expert Support

Get fitment advice & recommendations

Mon–Fri 8:30 AM – 8:00 PM

WhatsApp Email Us

24-Hour Fast Ship

Arrives in 3–14 Days

Worldwide Shipping

30-Day Returns

1 tree planted with every purchase

2-56 UNC Phillips Flat Head Countersunk Machine Screws — Bright Nickel Carbon Steel for Electronics, Models & Precision Builds

When you need small-diameter inch-standard fasteners that sit flush with the surface and won’t strip under a precision screwdriver, the options at most hardware stores fall short. Electronics assemblers, RC hobbyists, model builders, and instrument technicians who work with #2-56 UNC hardware regularly know how hard it is to find 2-56 UNC Phillips countersunk machine screws in bulk quantities with a clean, consistent finish. These 1/4" carbon steel bright nickel flat head screws are stocked in packs from 100 to 500 pieces, ready for production runs or workshop replenishment.

Each pack contains 2-56 UNC Phillips flat head (countersunk) machine screws in carbon steel with a bright nickel finish. Thread size is #2-56 UNC (approximately 0.086" / 2.18mm diameter, 56 threads per inch). Length is 1/4" (6.35mm / ≈6.4mm). The flat countersunk head profile allows the screw to sit flush with or below the mating surface. Packs are available in 100, 200, 300, 400, or 500 pieces.

Typical use cases include electronics enclosure assembly where #2-56 flat head screws are used to mount PCBs, panels, or covers flush without protruding heads; RC car and drone chassis builds where small UNC countersunk screws secure body panels and battery trays; and precision instrument repair and model making where the bright nickel finish provides a clean, reflective appearance on visible fastener locations.

ℹ️ Compatibility: 2-56 UNC thread standard (56 TPI) — fits standard #2-56 UNC tapped holes, threaded inserts, and nuts. Not compatible with metric M2 threads. Countersunk head angle is typically 82° (UNC standard) — verify your countersink angle before ordering.

✅ Key Features of These 2-56 UNC Phillips Countersunk Machine Screws

🔩Flush-Mount Flat Head Profile — The countersunk head sits flush with or below the mating surface, eliminating snag points on panels, enclosures, and chassis where protruding fastener heads are not acceptable in electronics or model builds.
✨Bright Nickel Finish — The electroplated bright nickel coating provides a shiny, decorative appearance and moderate corrosion resistance for indoor use — well-suited for visible fastener locations in precision instruments, hobby models, and electronics enclosures.
🇺🇸UNC Inch-Standard Thread — 2-56 UNC (56 threads per inch) is the standard thread for #2 machine screws in the United States, ensuring direct compatibility with existing #2-56 tapped holes, threaded inserts, and nuts without adapters or re-tapping.
📦Bulk Packs Up to 500 Pieces — Available in 100, 200, 300, 400, or 500-piece packs, making these #2-56 countersunk screws practical for production assembly, workshop stock, and repair kits without the cost premium of small retail packaging.
🔧Phillips Drive for Wide Tool Compatibility — The Phillips (cross) drive recess works with standard PH0 and PH1 screwdrivers and bits, which are universally available in electronics toolkits, making these screws easy to install in field repairs and bench assembly alike.
📏Consistent 1/4" Length Across All Pack Sizes — A single, well-defined length (1/4" / 6.35mm) simplifies inventory management and BOM sourcing for engineers and hobbyists who standardize on one screw specification across a product or build.

📐 Technical Specifications — 2-56 UNC Phillips Flat Head Countersunk Machine Screws

Thread Standard	2-56 UNC (Unified National Coarse, 56 threads per inch)
Nominal Diameter	#2 — approximately 0.086" (2.18mm)
Length	1/4" (6.35mm)
Head Style	Flat Head (Countersunk), Phillips Drive
Drive Type	Phillips — typically PH0 or PH1
Countersink Angle	Typically 82° (UNC standard) — contact us to confirm
Material	Carbon Steel
Finish	Bright Nickel Electroplating
Corrosion Resistance	Moderate — suitable for indoor / dry environments
Tensile Strength	Typically 60,000–74,000 psi (approx. 415–510 MPa) — contact us to confirm exact grade
Pack Quantities	100 / 200 / 300 / 400 / 500 pieces — see variant options
Country of Origin	Contact us to confirm

⚠️ Note: 2-56 UNC and metric M2 threads are not interchangeable. Verify your existing hardware uses #2-56 UNC before ordering. The countersink angle for UNC flat head screws is typically 82° — confirm your countersink matches before installation.

❓ Frequently Asked Questions

What does 2-56 UNC mean on a machine screw?

2-56 UNC refers to the Unified National Coarse thread standard. The “2” indicates the screw diameter (“#2”, approximately 0.086" or 2.18mm), and “56” means 56 threads per inch. UNC is the most common coarse thread series used in the United States for general-purpose fastening. It is the standard thread for #2 machine screws in American-made electronics, instruments, and equipment.

Is 1/4" the right length for my application?

A 1/4" (6.35mm) screw is typically suitable for fastening materials that are 1/8" to 3/16" thick, leaving adequate thread engagement in the mating material or nut. For countersunk applications, account for the depth of the countersink so the head sits flush with the surface. If your material is thicker than about 3/16", a longer #2-56 screw may be needed to achieve sufficient thread engagement.

What Phillips bit size do I need for a #2-56 screw?

A #2-56 machine screw typically uses a PH0 (Phillips #0) or PH1 (Phillips #1) driver bit, depending on the specific head size. Always test-fit the bit before applying torque — a loose-fitting bit will cam out and damage the drive recess. Using a precision screwdriver with a well-fitting PH0 bit is generally recommended for small screws like #2-56 to avoid stripping.

Are these screws compatible with standard #2-56 nuts and tapped holes?

Yes. These screws use the standard 2-56 UNC thread (56 threads per inch), which is compatible with standard #2-56 UNC nuts, threaded inserts, and tapped holes. They are not compatible with metric M2 threads, which have a different pitch (0.4mm) and a slightly different nominal diameter. If you are unsure which thread your existing hardware uses, check with a thread gauge before ordering.

How corrosion-resistant is bright nickel plating on carbon steel screws?

Bright nickel plating provides a decorative, shiny finish and moderate corrosion resistance for indoor use. It is generally suitable for dry or low-humidity environments such as electronics enclosures, hobby models, and indoor fixtures. The nickel layer protects the underlying carbon steel from light oxidation and surface rust in normal indoor conditions. For outdoor, marine, or high-humidity applications, stainless steel fasteners are generally a better choice.

How strong are #2-56 carbon steel machine screws?

Carbon steel #2-56 machine screws are generally rated to SAE Grade 2 or equivalent, with a tensile strength typically in the range of 60,000–74,000 psi (approximately 415–510 MPa). For small-diameter screws like #2, the actual load capacity is limited by the minor thread cross-section. These screws are suitable for light-duty fastening in electronics, models, and precision instruments — not for structural or high-load applications. Contact us to confirm the exact property class if your application has specific strength requirements.

Should I choose carbon steel or stainless steel for #2-56 countersunk screws?

Carbon steel with bright nickel plating (this product) is a good choice for indoor applications where a shiny, decorative finish is desired and corrosion is not a primary concern. Stainless steel is generally preferred for outdoor, humid, or corrosive environments. For most electronics, RC, and hobby applications in dry conditions, carbon steel bright nickel is typically sufficient and offers a cost advantage over stainless for bulk purchases.

🛒 Select your quantity above, then add to cart — ships from our US warehouse.