Wood Bolts Selection Guide | Hebei Wotu Fastener Manufacturing Co., Ltd.
Wood bolts are used to join timber members where the joint needs more controlled clamping than an ordinary wood screw can provide. The first decision is whether you need a through-bolt with a nut and washer, or a threaded wood fastener that anchors directly into the timber.
That distinction affects joint design, access to the rear of the assembly, hole preparation, washer support and resistance to loosening. Choosing the fastener around the actual timber connection prevents a common mistake: specifying a bolt by diameter alone while overlooking the load path and available installation space.
Brand: Wotu Surface: blue and white zinc plated Specifications: Chinese national standard 6#/8#/10#/12#/16#/20#, rod length 35mm~250mm full range of specifications in stock, supports nonstandard length customization Packaging: 25kg cartons, full pallets packed on wooden pallets, support neutral packaging, private-label customization
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Brand: Hengzuan Surface: color zinc plated, can be customizedblue-white zinc plated Specifications: in stock 4.8/5.5 common wire diameter, rod length 16~125mm full range of specifications, supports nonstandard customized Packaging: 25kg cartons, whole wooden pallets, support neutral packaging, private-label customization
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Brand: Wotu Surface: natural black oxide / hot-dip galvanized / blue-white zinc plated, multiple processes available Specifications: Based on common industry drawing parameters, suitable for pipe diameter 25mm~139.7mm, screw diameter M10~M24, total length can be nonstandard customized Matching: can be matched with nut, flat washer and spring washer of the same specifications for complete shipment Packaging: Bundling and packaging + 25kg export carton, full-container wooden pallet wrapped with film, supports private-label export packaging
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Brand: Hengzuan Surface: blue and white zinc plated, can be customized color zinc plated, black oxide plated Specifications: Comply with GB/T15856.2-2002 Chinese national standard, in stock ST4.2/ST4.8/ST5.5 full range of specifications, length 13mm~75mm optional, supports customized nonstandard rod lengths; drilling adaptation plate thickness 0.7~6mm Packaging: 25kg export cartons, full pallets wrapped with film, supports neutral export packaging, customer private-label customization
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Brand: Hengzuan Surface: blue and white zinc plated, can be customized color zinc plated, black oxide plated Specifications: in stock 3.5/3.9/4.2/4.8/5.5 mainstream wire diameter, rod length 13mm~75mm full size range, nonstandard length can be customized as needed Packaging: 25kg export cartons, full wooden pallets wrapped with film, supports neutral export packaging, private-label customization
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Brand: Hengzuan Surface: blue and white zinc plated, optional color zinc plated, black oxide treatment Specifications: Follow GB/T846-1985 Chinese national standard, in stock ST4.2/ST4.8/ST5.5 full range of specifications Packaging: 25kg export cartons, full pallets wrapped with film, supports neutral export packaging, private-label customization
Read MoreWood bolt selection
Compare wood-bolt options by connection type, thread engagement, usable length, head and nut arrangement, washer support, material or coating, timber condition and installation access. The correct choice depends on the complete joint assembly, not just the nominal fastener size.
| Criterion | What To Check | Why It Matters | Buyer Tip |
|---|---|---|---|
| Head style and bearing surface | Confirm whether the assembly needs a carriage-style square shoulder, a hex head, or another wood-bolt head pattern. | The head and shoulder determine how the fastener resists turning and how it seats against timber, plates, or brackets. | Ask which head and shoulder dimensions match your tool access and the joint detail. |
| Diameter, length, and usable thread | Compare the bolt diameter, overall length, unthreaded shank, and threaded engagement with the timber thickness and joint stack-up. | Too little thread reduces engagement; too much length can interfere with the opposite face, washer, or nut. | Provide the wood thickness, attached hardware thickness, washer space, and required nut engagement for confirmation. |
| Thread form for the wood joint | Verify whether the proposed wood bolt is intended for a pre-drilled timber joint and whether its thread length suits the clamped members. | A bolt normally passes through prepared holes and clamps the joint with a nut; it is not interchangeable with a wood screw that cuts its own thread. | Ask for a simple joint sketch showing which members are drilled and where the nut will sit. |
| Coating or material for the exposure | Match the finish or material to indoor, sheltered, outdoor, damp, or treated-timber use, then confirm compatibility with the surrounding hardware. | Moisture and chemical contact can accelerate corrosion, affecting service life and the ability to remove the nut later. | State the exposure conditions and timber treatment, and ask which finish or material is recommended for that environment. |
| Nut, washer, and hole fit | Check the matching nut thread, washer outside diameter, washer thickness, and clearance-hole size as one assembly. | A washer spreads clamping force on softer wood, while incorrect threads or a poorly sized hole can prevent proper tightening or damage the timber. | Ask for the complete bolt, nut, and washer combination and the recommended clearance-hole guidance for your timber. |
A through-bolt passes through the timber and is tightened with a nut, usually with washers to spread pressure across the wood. It suits joints where both sides are accessible and where the connection can be designed around a bolt, nut and washer assembly.
A lag-style or hexagonal wood fastener engages directly with the timber and is useful where the rear face cannot accept a nut. It may simplify assembly, but its holding performance depends more heavily on the timber condition, thread engagement and correct hole preparation. Confirm which type the drawing or engineer specifies before treating the terms as interchangeable.
Start with the joint, not the catalogue name. Record the timber thickness, the number and arrangement of members being joined, the direction of the expected load and whether the joint is structural or simply for positioning. A bolt that fits through the parts may still be unsuitable if its head, nut or washer cannot bear properly on the wood.
Choose the installation format. Through-bolts require access for the nut and enough space for washers and tightening. Direct-thread wood fasteners avoid a separate nut but need suitable thread engagement in sound timber. Do not substitute one for the other without checking the joint design, especially where movement, vibration or repeated loading is expected.
Match the finish to the environment. Interior dry timber, outdoor assemblies and damp or treated wood can place different demands on corrosion resistance and material compatibility. Confirm the required coating or material with the project specification, and check that the selected washer and nut finish will not create an avoidable compatibility problem.
Freeze the details before production. Confirm the bolt or fastener type, diameter, length, head style, thread form, washer and nut arrangement, finish, packaging and inspection requirements. If the request uses “wood bolts” broadly, send a joint sketch or a sample description showing whether the connection is through-bolted or threaded directly into timber. For applications that actually call for hexagonal wood screws, compare the specification points discussed in this guide to hexagonal wood screw specifications rather than assuming a bolt specification will transfer unchanged.
| Criteria | Importance | Description | Example Options |
|---|---|---|---|
| Connection format | This is the first decision because it determines access, tightening and how the load transfers through the timber. | Compare a through-bolt with nut and washers against a direct-thread wood fastener that anchors in the timber. | An accessible frame joint may allow a through-bolt, while an enclosed rear face may require a direct-thread option. |
| Installation access | Access can rule out an otherwise suitable fastener before size or finish is considered. | Check whether the installer can drill through the members, position washers and reach the nut or drive the fastener head. | A joint against a wall may not provide enough room for a nut and wrench. |
| Length and thread engagement | The fastener must fit the complete joint without leaving inadequate engagement or creating avoidable interference. | Account for the combined timber thickness, washer and head arrangement, plus the required threaded engagement for the selected format. | A direct-thread fastener needs sufficient embedment in sound timber; a through-bolt needs enough length for the nut and washers. |
| Bearing and washer arrangement | Wood can be compressed around the head or nut, so the bearing surfaces are part of the connection rather than an accessory detail. | Confirm washer presence, outside support and compatibility with the head, nut and timber surface. | A washer can spread clamping pressure across the timber instead of allowing a small head or nut surface to crush the wood. |
| Material or coating | The surrounding environment and timber treatment affect the corrosion-resistance decision and component compatibility. | Match the fastener finish or material to dry indoor, outdoor, damp or treated-timber conditions, and check the nut and washer arrangement at the same time. | An outdoor assembly may require a different finish from a dry interior joint; confirm the required system with the project specification. |
Related Options
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ost anchor bolt ordering errors come from incomplete drawings, unclear dimensions, unsuitable material or coating choices, undefined tolerances, and mismatched nuts or washers. These mistakes affect steel fabricators, EPC contractors, equipment installers, importers, and distributors because anchor bolts are usually embedded before the connected structure arrives on site. Once concrete has cured, even a small […]
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Direct answer: Choose a self-drilling screw when the fastener must create a hole through a verified metal stack before its threads engage. Choose a self-tapping screw when the assembly already has a correctly sized pilot hole or when the selected thread is intended to form or cut into the specified substrate. The decision must also […]
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DIN 931-style half-thread and DIN 933-style full-thread hex bolts should not be selected from diameter and overall length alone. The practical choice depends on the joint stack, required grip, location of the thread transition, available nut engagement, mating hardware, material or property requirement, coating system and governing product specification. A half-thread bolt is not automatically […]
Hot-dip galvanized bolts are widely used in daily life, especially due to their advantages, which have led to their rapid development in the market and widespread consumer appeal. So what are the specific advantages of hot-dip galvanized bolts in use? Today, Hebei Wotu Fastener Manufacturing Co., Ltd. will discuss this with you. 1. Due to […]
Choose a through-bolt when both sides of the timber joint are accessible and the design allows a nut and washers. A direct-thread fastener is more practical when the rear face is enclosed, but its suitability depends on sound timber, adequate thread engagement and the specified hole preparation.
A hexagonal wood screw can suit an assembly where the fastener must engage directly with the timber and no rear nut is possible. It is not an automatic substitute for a through-bolt; compare the load path, required embedment, head support and installation method against the joint design.
No. Joint performance also depends on fastener length, thread engagement, timber condition, edge and end distances, washer bearing and the direction of the load. An oversized fastener can create installation or splitting problems if the surrounding timber and joint layout are not designed for it.
Not normally, because tightening requires access for the nut and usually a washer. If the rear face is inaccessible, ask the designer to confirm whether a direct-thread wood fastener or another connection method is appropriate instead of changing the fastener type during ordering.
State the connection type, timber thickness and member arrangement, required diameter and length, head style, thread form, washer and nut arrangement, finish or material, quantity and packaging needs. A joint sketch or clear sample description is especially useful when “wood bolts” could refer to either a through-bolt assembly or a fastener threaded directly into timber.
Tell us the timber thickness and joint arrangement, whether the assembly allows a nut and washer on the rear side, and the intended environment or finish. Include the required quantity if you are planning a production order.
