#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"
#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"
#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"
#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"
#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"
#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"
#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"
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#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"

#2–5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket, Lengths 3/16"–2"

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$2.11 USD
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In stock (500 units), ready to be shipped

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Description

🔩 #2 to 5/16" UNC Allen Button Head Machine Screws – A2 Stainless Steel, Hex Socket Drive

You're building a custom motorcycle part, repairing a piece of outdoor furniture, or working on a marine project – and you need bolts that look clean, sit low, and won’t rust. These UNC button head socket screws are made from A2 stainless steel (304), so they stand up to salt spray, rain, and humidity. The low‑profile button head gives a smooth, finished look without sticking out, while the hex socket (Allen) drive lets you torque them down without slipping. Choose from #2 through #10, 1/4", or 5/16" UNC thread sizes, with lengths from 3/16" up to 2" (measured under the head). Keep a variety in your shop for machinery, automotive trim, electronics enclosures, or any project where you want strength and corrosion resistance in a compact package.

✨ Key Features – UNC Allen Button Head Stainless Steel Screws

  • 🔘 Low profile button head – Sits close to the surface with a smooth, rounded top. Great for applications where you don’t want a protruding head, like panel mounting or handrails.
  • 🛡️ A2 stainless steel (304) – Excellent corrosion resistance. Perfect for outdoor, marine, coastal, and food‑area use. Won’t rust or stain like plain steel.
  • 🔧 Hex socket (Allen) drive – Allows for high torque without cam‑out. Uses standard hex keys (Allen wrenches) in metric or imperial sizes depending on screw.
  • 📏 UNC coarse thread – Unified National Coarse standard, widely used in North America. Good for quick assembly and resistant to cross‑threading.
  • 📐 Wide size range – From tiny #2 UNC up to 5/16" UNC. Lengths from 3/16" to 2" (under head). Longer bolts may be partially threaded.
  • 💪 Durable & burr‑free – High‑quality A2 stainless with smooth threads and clean machining. No sharp edges.
  • 🧰 Versatile applications – Automotive, marine hardware, furniture, machinery guards, electronics chassis, and DIY projects.

📏 UNC Button Head Socket Screw Sizes – A2 Stainless Steel

Thread Size (UNC) Threads per Inch (TPI) Available Lengths (inches, under head)
#2 UNC 56 3/16" – 1" (varies by listing)
#4 UNC 40 3/16" – 1"
#6 UNC 32 3/16" – 1-1/2"
#8 UNC 32 3/16" – 2"
#10 UNC 24 3/16" – 2"
1/4" UNC 20 1/4" – 2"
5/16" UNC 18 3/8" – 2"

📐 Length is measured from under the button head to the tip. Longer bolts may have partial threads (unthreaded shank near the head).

📋 Technical Details – Allen Button Head Machine Screws

Parameter Details
Product name UNC Hex Socket Button Head Machine Screws / Bolts
Material A2 Stainless Steel (304 / 18-8)
Head style Button head (low profile, rounded)
Drive style Hex socket (Allen key)
Thread standard UNC (Unified National Coarse)
Thread sizes #2, #4, #6, #8, #10, 1/4", 5/16" UNC
Length range 3/16" to 2" (under head – does not include head height)
Grade Approx. Grade 4.8 (typical for A2 stainless)
Finish Natural / uncoated stainless (bright)

❓ Frequently Asked Questions – UNC Button Head Allen Screws

1. What does UNC mean? Are these threads compatible with standard nuts?

UNC stands for Unified National Coarse – the standard coarse thread system used in the US and Canada. These screws will mate perfectly with UNC nuts of the same size (e.g., #10‑24 nut, 1/4‑20 nut, 5/16‑18 nut). They will not fit metric nuts or fine thread (UNF) nuts.

2. How do I measure the length of a button head screw?

For button head screws, length is measured from the underside of the head (the flat bearing surface) to the tip of the screw. The button head itself is not included in the length. So a “1/4‑20 x 1” screw has a 1‑inch long threaded portion (or partially threaded shank) under the head.

3. Are these screws fully threaded?

Shorter lengths (typically up to 1") are usually fully threaded. Longer bolts may have a partial thread – meaning an unthreaded shank near the head. This is standard for longer socket screws. Check the product images or contact us if you need full thread for a specific length.

4. What hex key size do I need for each screw?

Hex key sizes vary by screw diameter. Typical sizes: #2 uses 0.035", #4 uses 0.05", #6 uses 1/16" (1.5mm), #8 uses 5/64" (2mm), #10 uses 3/32" (2.5mm), 1/4" uses 7/64" (2.5–3mm), 5/16" uses 1/8" (3mm). We recommend checking the screw head or using the key that fits snugly – most Allen key sets include these sizes.

5. Are these good for saltwater marine use?

A2 stainless (304) is suitable for freshwater and occasional saltwater exposure, but for continuous saltwater immersion (e.g., below deck, fittings on a boat that’s always in the water), we recommend A4 (316) stainless for better pitting resistance. For above‑deck hardware or coastal use, A2 is fine.

6. Can I get custom lengths or larger quantities?

Yes – we offer many lengths from the dropdown. If you need a length not listed or bulk packs, contact our customer service. We can custom order or provide volume pricing.

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