Zinc Coated Phillips
Flat Head Wood Screws

Perfectly Flush. No Proud Heads.

Installs Clean. Stops Wood Splitting.

Engineered for Faster, Cleaner Countersinks.

Sinsun Flat Head Wood Screws: The Flush Finish Experts

Achieve a perfect flush finish with Sinsun flat head wood screws. Expertly engineered for strength & a seamless look in furniture, trim, and fine woodworking. Explore professional-grade options.

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flat wood screws Introduction The Art of
the Invisible Fastener

Sinsun Flat Head Wood Screws are engineered for a perfect flush finish.

Their 82-degree head angle matches standard countersinks for seamless integration into wood surfaces.

Made from heat-treated steel, they provide reliable fastening for cabinetry, flooring, and furniture assembly.

These screws reduce installation time with their self-starting point, minimizing pre-drilling and wood splitting.

Corrosion-resistant coatings offer over 1,000 hours of salt spray protection, ensuring long-term durability for interior and exterior applications.

Sinsun Flat Head Wood Screws: A Comprehensive Material & Drive Solution for Every Finish Requirement

Brass Wood Screws Flat Head

Sinsun brass screws are made from a high-copper alloy, typically CuZn39Pb3, which makes them very resistant to corrosion. This makes them great for marine hardware and decorative joinery. The flat head is cut with great care so that it fits perfectly in a countersunk hole. Our work-hardened brass is softer than steel but still strong enough for most non-structural uses in wood. It is also great for places where it needs to be non-magnetic or non-sparking.

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Black Flat Head Wood Screws

The black oxide or epoxy-polyester coating on these screws is strong and long-lasting. It is applied using electrochemical or spray-and-bake methods. The coating gives the zinc plating a smooth, matte finish that looks good and is less likely to corrode than regular zinc plating. In neutral salt spray tests, it usually lasts 96 to 120 hours. The black finish on Sinsun's products is designed to not chip during installation.

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Flat Head Stainless Steel Wood Screws

These screws are made of Austenitic A2-304 or marine-grade A4-316 stainless steel, which makes them the most resistant to rust. They are necessary for outdoor furniture, coastal uses, or chemical environments where rust stains are not acceptable. Sinsun's stainless flat heads are completely non-magnetic and have a consistent tensile strength of at least 500 MPa for 304.

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White Flat Head Wood Screws

These are regular steel screws with a white powder coat of polyester or epoxy that adheres to them. The coating provides appliances, white furniture, or trim work a clean, color-matched finish.As a result of Sinsun's process, the coating adheres well enough to last for a long time without chipping.

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Flat Head Square Drive Screws

These screws have a Robertson/square recess drive, which gives them much better torque transfer and less cam-out than Phillips drives. The square drive stops the bit from slipping and wearing down. In North America, Sinsun offers this type of drive on many of its flat head screws, where it is preferred for its reliability and efficiency.

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Large Flat Head Wood Screws

This category includes screws with diameters from #14 (6.3mm) up to 1/4" (6.35mm) and lengths exceeding 3". Designed for structural joinery, such as attaching heavy timber or large hardware. Sinsun manufactures these with a reinforced shank and deep-cut threads to achieve high withdrawal values, often replacing lag bolts where a flush finish is needed.

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Why Choose Sinsun Flat Head Screws?

Aesthetic Excellence

The 82° counter-sunk head sits flush in the pre-drilled pilot hole, creating a smooth, snag-free surface ready for filling or leaving bare.

Superior Holding Power

The sharp point and aggressive coarse threads bite deeply into wood, providing excellent pull-out resistance and shear strength for durable joints.

Material & Finish Variety

Available in Steel (with Zinc, Brass, or Black Oxide finish), Stainless Steel (304/316), and Solid Brass to match your project's functional needs and aesthetic style, from indoor furniture to outdoor applications.

Driving Efficiency

Offered with Phillips (PH), Pozidriv (PZ), and Torx (T) drives. In order to ensure a clean installation every time, we recommend Torx for superior torque transfer and cam-out prevention.

Sinsun flat head timber screws: Technical Specifications & Product Models

Technical Parameters

Parameter	Specification	Standard / Detail
Drive Type	Phillips (PH)	PH2 (#6, #7, #8), PH3 (#10)
Head Angle	82° Included Angle	Matches standard countersink bits.
Thread Type	Coarse Thread, Partial/Full	Sharp, deep-cutting threads for fast engagement in wood.
Point Type	Type 17 (Auger Point)	Sharp, self-starting point minimizes wood splitting.
Material	Low-Carbon Steel / Stainless Steel (AISI 304)	Heat-treated for optimal strength and ductility.
Surface Finish	Bright Zinc Plated / Electro-Brass / Black Oxide	Corrosion-resistant coating; Salt spray resistance ≥ 1000 hours (Zn).
Tensile Strength	≥ 1000 N/mm² (Steel)	Grade 4.8 or higher.
Standard Compliance	DIN 7997 / ANSI / Relevant Industry Standards

Product Model Specifications

Standard Series - Zinc Plated

Screw Gauge	Diameter (mm)	Length (mm) - Available Sizes	Thread Length	Packaging (Qty)
#6	3.5	13, 16, 19, 22, 25, 30, 38	Full Thread	100, 200, 500 pcs/box
#7	3.9	16, 19, 22, 25, 30, 38, 50	Full Thread	100, 200 pcs/box
#8	4.2	19, 22, 25, 30, 38, 50, 64	Full Thread	100, 200 pcs/box
#10	4.8	25, 30, 38, 50, 64, 76, 89, 100	Partial Thread (approx. 2/3 of length)	50, 100 pcs/box

Note:
Length Tolerance: ±0.5mm (for lengths ≤ 50mm), ±1.0mm (for lengths > 50mm).

Pilot Hole Recommendation:
Softwood: Typically not required with Type 17 point.
Hardwood/Edges: Use a pilot hole slightly smaller than the screw's core diameter.
Custom lengths, finishes (e.g., stainless steel 304/316), and packaging are available upon request.

Sinsun flat head wood screws make clean, flush joints easy. They stay tight in furniture, flooring, and decks, so your projects look polished and last.

Application Spotlight: Flat Head vs. Other Common Heads

Not sure which screw head is right for your job? This comparison highlights where Flat Head excels.

Feature	Flat Head (Countersunk)	Pan Head	Round Head	Hex Head
Primary Goal	Flush, invisible finish	Wider bearing surface, slightly domed	Decorative, high-profile dome	High-torque driving with wrench
Best For	Furniture, cabinets, trim, flooring	Attaching metal brackets/parts to wood	Vintage/decorative hardware, electrical boxes	Heavy framing, decking, where head visibility is okay
Installation	Requires pilot hole & countersink	Often used with washer; may sit above surface	Sits above surface; pilot hole usually needed	No countersink; driven with socket/wrench
Finish	Can be filled & sanded for seamless look	Functional, industrial look	Ornamental look	Utilitarian, very strong appearance

Customer Projects & Feedback

As a custom furniture maker, I rely on Sinsun's brass flat head screws for attaching tabletop brackets. They disappear into the wood, and the quality is consistently superb—no stripped drives or poorly formed heads.”

— Elena M., Artisan Woodshop

“We use the #8 x 1-1/4" stainless steel flat heads for all our outdoor teak furniture assembly. They resist corrosion beautifully and give us that high-end, clean look clients expect.”

— David L., Outdoor Furniture Co.

“The Torx drive flat heads have sped up our cabinet installation significantly. No more frustrating cam-out when driving screws into hardwood frames.”

— Precision Kitchen Installers Team

FAQ

What are ‘large flat head wood screws’ typically used for?

Large flat head wood screws are ideal for heavy timber construction where a strong, flush finish is needed, such as in deck posts, beams, or large outdoor furniture.

What makes a ‘flat head timber screw’ different from a regular wood screw?

A flat head timber screw often has a sharper point, coarser threads, and a stronger hardened steel construction specifically designed for fast and secure driving into hardwoods and structural timber.

Why would I buy ‘2 flat head wood screws’?

Purchasing 2 flat head wood screws is perfect for a small repair job or a DIY project where you only need a couple of fasteners to complete the task, avoiding buying a full box.

When should I use ‘flat head cabinet screws’?

Use flat head cabinet screws for assembling cabinets and fine furniture, as their flat heads can be countersunk cleanly below the wood surface and concealed with a plug or filler for a smooth finish.

What does ‘5/16’ refer to in a ‘5 16 flat head wood screw’?

In a 5 16 flat head wood screw, ‘5/16’ usually refers to the major diameter of the screw’s shank, which is approximately 5/16 of an inch or about 7.9mm.

What are ‘flat screws for wood’ called?

Flat screws for wood are commonly called flat head wood screws or countersunk wood screws, designed to sit flush with or below the wood surface.

What is a common use for a ‘1 inch flat head screw’?

A 1 inch flat head screw is commonly used for attaching thin materials like drawer slides, hardware, or trim pieces where a short, flush fastener is required.

Where would I need ‘2 inch flat head screws’?

2 inch flat head screws are versatile for medium-duty projects like building frames for small furniture, assembling porch railings, or securing 1x lumber where substantial holding power is needed.

How strong is a ‘14 flat head wood screw’?

A 14 flat head wood screw refers to a #14 gauge screw, which has a shank diameter of about 6.3mm, offering significantly higher shear and tensile strength than smaller gauges for robust connections.

Your Next Steps to a Flawless Finish

Identify Your Need:

Determine the material (hardwood, softwood, outdoor?), thickness, and desired finish.

Select Your Screw:

Use the table above to choose the correct gauge, length, and material/finish.

Perfect the Installation:

Remember the two-step pre-drill (pilot + countersink) for a perfect result.

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