coach screws
Made from High Tensile Grade 8.8 Steel Conforms to DIN571 standards High-Temperature Quenching Treatment, High Hardness, Wear Resistance
Advantages of Sinsun Coach Screw
Sinsun Coach Screw is a high strength 8.8 grade carbon steel heavy gauge self tapping wood screw (also known as a “lag screw”) designed for heavy duty structural connections. Our Coach Screw are your go-to solution for fastening wood to wood, machine foot to wood flooring.
♦Uniform size and arrangement ensure tool compatibility, reducing the risk of staple jams or misalignment
♦Surface treatment: Sinsun’s lag screw can be hot-dip galvanized, Dacromet or phosphating, which can effectively prevent rust and corrosion.
♦Thread design: Sinsun’s coach screw is a self-tapping pointed design with a hexagonal flange head, which is convenient for tool installation and enhances anti-loosening
♦Strict quality control system:Sinsun’s carriage screws have passed ISO 9001 quality management certification and full-process testing (hardness test, salt spray test, etc.)
Expert In The Production Of Carriage Screws
Sinsun’s mastery in coach screw engineering. For 19 years, we have been constantly improving the technology of connecting heavy wood and metal under load – each screw is cold-forged from 8.8 and 10.9 grade steel, and the threads are precision rolled to firmly grasp the wood fibers and prevent cracking.
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Sinsun Coach Screw Series
Sinsun offers a range of Hexagon Head Coach Screws made of A2(304) stainless steel or A4 (316) marine grade stainless
Galvanised Coach Screw
Sinsun’s galvanized Coach screws are very strong. This is because Sinsun reiterates that the raw materials of the coach
Long Coach Screws
Another common surface treatment for Sinsun’s Lag screws is Zinc Plated, which complies with DIN 571. Our Bright Zinc
Black Coach Screws
Sinsun offers a range of Hexagon Head Coach Screws made of A2(304) stainless steel or A4 (316) marine grade stainless
Square Head Coach Screws
Sinsun’s galvanized Coach screws are very strong. This is because Sinsun reiterates that the raw materials of the coach
Hex Coach Screw
Sinsun offers a range of Hexagon Head Coach Screws made of A2(304) stainless steel or A4 (316) marine grade stainless
Exterior Coach Bolts
Sinsun’s galvanized Coach screws are very strong. This is because Sinsun reiterates that the raw materials of the coach
Countersunk Coach Screws
Another common surface treatment for Sinsun’s Lag screws is Zinc Plated, which complies with DIN 571. Our Bright Zinc
Sinsun Brings For You
Coach Screw Details
Galvanised Carriage Bolts
Stainless Steel Coach Screw
⇒ Coach Screws, the secret of solid construction
⇒ rust-resistant coating, guarding the mission of every screw
Common Coach Screw Sizes
M8 Coach Bolts
M10 Coach Screw
M12 Coach Screws
M5 Coach Bolts
M6 Coach Screw
M16 Coach Screws
100mm Coach Screws
200mm Coach Screws
150mm Coach Screws
300mm Coach Bolts
250mm Coach Screws
8mm Coach Bolts
| SKU | Description | Head | Surface Treatment |
| SS202504234 | m8 coach bolts | Hex Head | GAL |
| SS202504234 | m10 coach screw | Hex Head | GAL |
| SS202504234 | m12 coach screws | Hex Head | GAL |
| SS202504234 | 200mm coach screws | Hex Head | GAL |
| SS202504234 | 150mm coach screws | Hex Head | GAL |
| SS202504234 | 200mm coach bolts | Hex Head | GAL |
| SS202504234 | 150mm coach bolts | Hex Head | GAL |
| SS202504234 | 100mm coach screws | Hex Head | GAL |
| SS202504234 | 300mm coach bolts | Hex Head | GAL |
| SS202504234 | 10mm coach bolts | Hex Head | GAL |
| SS202504234 | 8mm coach screws | Hex Head | GAL |
| SS202504234 | 250mm coach screws | Hex Head | GAL |
| SS202504234 | 8mm coach bolts | Hex Head | GAL |
| SS202504234 | 6mm coach bolts | Hex Head | GAL |
| SS202504234 | 10mm coach screws | Hex Head | GAL |
| SS202504234 | coach bolts 6mm | Hex Head | GAL |
| SS202504234 | 300mm coach screws | Hex Head | GAL |
| SS202504234 | 100mm coach bolts | Hex Head | GAL |
| SS202504234 | 250mm coach bolts | Hex Head | GAL |
| SS202504234 | 120mm coach bolts | Hex Head | GAL |
| SS202504234 | 50mm coach screws | Hex Head | GAL |
| SKU | Nominal Dia. | Length | Hex (A/F) | Coating |
| SS20250511 | M8 | 30mm | 13mm | HDG、ZINC PLATED |
| SS20250512 | M8 | 40mm | 13mm | HDG、ZINC PLATED |
| SS20250513 | M8 | 50mm | 13mm | HDG、ZINC PLATED |
| SS20250514 | M8 | 65mm | 13mm | HDG、ZINC PLATED |
| SS20250515 | M8 | 75mm | 13mm | HDG、ZINC PLATED |
| SS20250516 | M8 | 100mm | 13mm | HDG、ZINC PLATED |
| SS20250517 | M10 | 40mm | 17mm | HDG、ZINC PLATED |
| SS20250518 | M10 | 50mm | 17mm | HDG、ZINC PLATED |
| SS20250519 | M10 | 65mm | 17mm | HDG、ZINC PLATED |
| SS20250520 | M10 | 75mm | 17mm | HDG、ZINC PLATED |
| SS20250521 | M10 | 90mm | 17mm | HDG、ZINC PLATED |
| SS20250522 | M10 | 100mm | 17mm | HDG、ZINC PLATED |
| SS20250523 | M10 | 120mm | 17mm | HDG、ZINC PLATED |
| SS20250524 | M10 | 130mm | 17mm | HDG、ZINC PLATED |
| SS20250525 | M10 | 150mm | 17mm | HDG、ZINC PLATED |
| SS20250526 | M12 | 40mm | 19mm | HDG、ZINC PLATED |
| SS20250527 | M12 | 50mm | 19mm | HDG、ZINC PLATED |
| SS20250528 | M12 | 65mm | 19mm | HDG、ZINC PLATED |
| SS20250529 | M12 | 75mm | 19mm | HDG、ZINC PLATED |
| SS20250530 | M12 | 90mm | 19mm | HDG、ZINC PLATED |
| SS20250531 | M12 | 100mm | 19mm | HDG、ZINC PLATED |
| SS20250532 | M12 | 120mm | 19mm | HDG、ZINC PLATED |
| SS20250533 | M12 | 130mm | 19mm | HDG、ZINC PLATED |
| SS20250534 | M12 | 150mm | 19mm | HDG、ZINC PLATED |
| SS20250535 | M12 | 180mm | 19mm | HDG、ZINC PLATED |
| SS20250536 | M12 | 200mm | 19mm | HDG、ZINC PLATED |
| SS20250537 | M16 | 50mm | 24mm | HDG、ZINC PLATED |
| SS20250538 | M16 | 75mm | 24mm | HDG、ZINC PLATED |
| SS20250539 | M16 | 100mm | 24mm | HDG、ZINC PLATED |
| SS20250540 | M16 | 130mm | 24mm | HDG、ZINC PLATED |
| SS20250541 | M16 | 150mm | 24mm | HDG、ZINC PLATED |
| SS20250542 | M16 | 200mm | 24mm | HDG、ZINC PLATED |
| SS20250543 | M20 | 100m | 24mm | HDG、ZINC PLATED |
Coach Screw Production Expert
If you are looking for a Coach screw manufacturer, Sinsun Fastener can definitely meet all your lag screw needs.
Sinsun specializes in the production of Coach screws, including high-strength carbon steel, 304 stainless steel, 316 stainless steel and surface treatments such as galvanizing to meet your various needs and budgets.
All Sinsun coach screws are manufactured in accordance with specific AS 1393, DIN 571 standards.
Over the past 19 years, Sinsun has accumulated rich experience in the design and manufacture of Coach screws, but most importantly, our understanding of the standards used and the ability to work with other suppliers to meet these standards.
Coach Screws of Application
Coach Bolts For Wood
Coach Bolts For Wood is a good partner for all-round woodworking.
Dome head bolts designed for wood, smooth round head does not scratch hands, suitable for exposed parts, square neck anti-rotation design, flat surface without protrusions after installation, rust-proof and pressure-resistant, the first choice for wood structure connection!
1️⃣ Solid wood furniture assembly：Bed frame, dining table leg reinforcement，Cabinet load-bearing beam connection
2️⃣ Outdoor wood structure Pavilion column fixing，Wooden fence beam splicing
3️⃣ Decoration project：Wooden wall installation
Reinforcement of retro wooden door hinges
Coach Screws For Decking
Coach Screws for Decking are rust-proof fasteners designed for anti-corrosion wood decks. They are made of 304 stainless steel/hot-dip galvanized material, resistant to moisture and salt spray, and will not loosen for 10 years!
1️⃣ Deck floor fixing: Anti-corrosion wood board is connected to keel, square neck is embedded in keel to prevent wood board displacement, round head sinking design, flat foot feeling and no foot pain
2️⃣ Railing column installation: handrail column and ground beam reinforcement, M12 screws resist lateral force ≥200kg, 45° bevel drive, enhanced wind resistance
3️⃣ Edge closing reinforcement: deck edge anti-slip board, extension rod design (150-300mm) Coach Screws run through multi-layer structure
4️⃣ Step pedal connection: step and frame bearing point, coarse thread (3TPI) fast bite hardwood
Coach Bolts For Concrete
Sinsun’s Coach Bolts for Concreteis a reinforced fastener designed for concrete substrates, carbon steel quenching + galvanizing, pre-buried installation, vibration and corrosion resistance.
1️⃣ Steel structure base fixing: connection between factory steel columns, equipment and concrete foundation, M16 bolt shear strength ≥ 50kN, galvanized layer to prevent oil corrosion
2️⃣ Outdoor guardrail installation: ground fixing of fence railings and traffic isolation piles, 304 stainless steel material to prevent rainwater rust
3️⃣ Building curtain wall anchoring: connection between stone/metal curtain wall keel and concrete wall
4️⃣ Underground pipe gallery bracket: underground anchoring of cable trays and pipe brackets
Coach Bolts For Fence Posts
Coach Bolts for Fence Posts: The Cornerstone of Durable Enclosures
Coach Bolts, with their unique Square Neck anti-rotation design and low-visibility Dome Head, have become the preferred fastening solution for fence post installation
1️⃣ Wooden post-beam corner fixation: The 90° corner connection between the anticorrosive wood/carbonized wood post and the beam needs to resist lateral wind load (≥0.6kN/m²)
2️⃣Metal post and concrete base anchoring: When the steel post is embedded in the concrete foundation, it needs to overcome vibration
3️⃣ Decorative fence flexible connection: The artistic nodes of cast iron/aluminum art railings need to be concealed and fastened with slight elasticity
4️⃣High-strength livestock fence node reinforcement: Bear livestock impact load (cattle instantaneous impact force ≥3kN), need to prevent rust and loosening
Why is Sinsun's coach screw worth choosing?
Special Grade Steel
Made of high-quality stainless steel and high-carbon steel, 30% harder than standard screws for heavy-duty anchoring.
There are no industry pain points such as breakage, deformation, and rust! No need to pre-drill, one-shot penetration from concrete to hardwood
Zero-Rust Guarantee
Sinsun’s Coach Screws use 7 customized surface treatment technologies to protect each screw. The Dacromet coating can withstand 1000 hours of salt spray, the hot-dip galvanized layer builds a nano-defense line in acid and alkali, and the ceramic oxide film can withstand 800℃ high temperature. With a ten-year warranty
Exclusive Design
Coach Screws’ laser-calibrated threads (±0.02mm fatal accuracy) lock every nanometer bite! The vibration lasts for 72 hours, and the 0 thread slip rate still protects the safety of the seam; from the heart of precision instruments to the steel joints of shield machines, we use more stringent error standards than hair.
Global Trust
Sinsun’s Coach Screws comply with strict standards of 0.01mm settlement error and ISO/FSC dual certification. From extremely cold concrete to desert quicksand, from EU environmental directives to extreme climates in the Middle East, we use the “zero-compromise engineering philosophy” to cross borders.
FAQ
Q1: Do carriage screws need to be pre-drilled?
A: Must! Drill holes of 2/3 screw diameter in wood (such as 6-7mm for M10), and special impact drills are required for holes in concrete (1-2mm smaller in diameter).
Q2: Which anti-rust treatment should be selected for outdoor wooden floors?
A: 316 stainless steel is used in coastal/high humidity areas, and hot-dip galvanizing (85μm coating + sealer) is recommended inland, which is 30% cheaper and equally durable.
Q3: What should I do if the square neck cannot hold the wood?
A: ①Confirm that the hole diameter is ≤0.5mm of the square neck size ②Use a rubber hammer to knock into the square neck section ③Apply wood wax oil to lubricate hardwood first.
Q4: What should I do if the screw breaks halfway through the screwing?
A: Use a reverse thread extractor (specifications M6-M24) + WD-40 for lubrication. Do not force welding – it will destroy the strength of the substrate!
Q5: Can the carriage screws be reused?
A: Not recommended! After the threads are engaged, they will wear out, and the load-bearing capacity will drop by 40% after secondary use. Key structures must be replaced.
Q6: How to determine whether the screw length is appropriate?
A: Total length = board thickness + 1/3 anchor depth (e.g. 30mm board + concrete anchor → choose 120mm screws).
Q7: How to hide round head screws?
A: ① Use countersunk drill bits to make chamfers ② Fill with wood wax paste/epoxy resin ③ Apply wood grain patches to perfectly cover.
Q8: Which is better, carriage screws or expansion bolts?
A: Carriage screws (anti-crack) are selected for wood/composite materials, expansion bolts (higher pull-out force) are used for pure concrete, and nylon sleeves are required for transition of mixed substrates.
