Bolts & Coach Screws – DIN 571, DIN 603, DIN 931 & DIN 933
Bolts and wood screws for timber construction, fencing, building and garden projects, available from Intergard in a range of sizes, materials and finishes. The range includes carriage bolts DIN 603, wood screws DIN 571 and hexagon bolts DIN 931 and DIN 933. Depending on the product, galvanised and stainless steel versions are available.
The right fixing depends on the materials being joined, the type of connection and the conditions in which it will be used. Carriage bolts DIN 603 are commonly used for through-bolted timber connections. Wood screws DIN 571, also commonly known as coach screws in the UK, are screwed directly into suitable timber. Hexagon bolts DIN 931 and DIN 933 are used for a wide range of bolted connections in construction and assembly work.
Browse our carriage bolts DIN 603, wood screws DIN 571, hexagon bolts DIN 931 and hexagon bolts DIN 933 to find the right fixing for your project.
Bolts and Wood Screws for Timber, Building and Garden Projects
Bolts and wood screws are used to create different types of connections in timber, metal and other suitable construction materials. Depending on the fixing, the connection may be made with a nut and washer, into a suitable threaded component or directly into timber.
Within our bolts range, Intergard offers four main types of DIN fastener: carriage bolts DIN 603, wood screws DIN 571, hexagon bolts DIN 931 and hexagon bolts DIN 933. They are suitable for different applications in timber construction, fencing, garden structures, building and general assembly work.
Which Bolt or Wood Screw Do You Need?
Choose your fixing according to the materials being joined, the type of connection, diameter, length, thread and conditions of use. DIN 603, DIN 571, DIN 931 and DIN 933 fasteners have different designs and are not interchangeable.
- DIN 603: carriage bolt with a rounded head and square neck, commonly used for through-bolted connections.
- DIN 571: hexagon-head wood screw, commonly called a coach screw in the UK, for certain direct fixings into timber.
- DIN 931: hexagon bolt with a partially threaded shank according to the relevant standard.
- DIN 933: hexagon bolt with thread extending over the length defined by the relevant standard.
Carriage Bolts DIN 603
DIN 603 carriage bolts have a rounded head and a square neck immediately below the head. When fitted into a suitable material, the square neck can help prevent the bolt from turning while the nut is tightened.
This makes carriage bolts useful for many through-bolted timber connections, including fencing, gates and other timber structures. The rounded head also provides a relatively smooth surface on the visible side of the connection.
View all carriage bolts DIN 603.
Galvanised Carriage Bolts DIN 603
Galvanised DIN 603 carriage bolts have a zinc coating that helps delay corrosion of the underlying steel. Suitability for a particular application depends on the finish, environment and conditions of exposure.
View our galvanised carriage bolts DIN 603.
Stainless Steel Carriage Bolts DIN 603
Stainless steel DIN 603 carriage bolts provide a high level of corrosion resistance. The stainless steel grade should always be checked against the environment and intended application.
View our stainless steel carriage bolts DIN 603.
Wood Screws DIN 571 for Timber
DIN 571 wood screws are heavy-duty hexagon-head screws used for certain direct fixings into timber. In UK terminology they are also widely known as coach screws. Unlike a conventional through-bolt and nut connection, a DIN 571 wood screw is driven directly into suitable timber or used as part of an appropriate fixing system.
DIN 571 wood screws can be used for various timber applications involving posts, beams, pergolas, fences and garden structures. The required diameter and length depend on the components being fixed and the requirements of the construction.
View all wood screws DIN 571.
Galvanised Wood Screws DIN 571
Galvanised DIN 571 wood screws have a protective zinc coating that helps delay premature corrosion of the steel. Galvanising does not make steel completely rust-proof, and suitability for outdoor use depends on the exposure conditions.
View our galvanised wood screws DIN 571.
Stainless Steel Wood Screws DIN 571
Stainless steel DIN 571 wood screws are often selected where corrosion resistance is an important consideration. Different stainless steel grades have different properties, so check the product specification for the intended application.
View our stainless steel wood screws DIN 571.
Hexagon Bolts DIN 931
DIN 931 hexagon bolts have a hexagonal head and a partially threaded shank according to the relevant standard. They are used for many types of bolted connection and are normally combined with a compatible nut and, where required, a washer.
When choosing a DIN 931 hexagon bolt, check the diameter, length, threaded section, material, finish and technical requirements of the connection.
View all hexagon bolts DIN 931, including galvanised DIN 931 hex bolts and stainless steel DIN 931 hex bolts.
Hexagon Bolts DIN 933
DIN 933 hexagon bolts have a hexagonal head and thread extending over the length defined by the relevant standard. This is one of the main differences compared with DIN 931 hexagon bolts with a partially threaded shank.
DIN 933 bolts are used for a wide range of construction and assembly applications. Depending on the connection, they may be combined with a compatible nut and washer or screwed into a suitable internally threaded component.
View all hexagon bolts DIN 933, including galvanised DIN 933 hex bolts and stainless steel DIN 933 hex bolts.
What Is the Difference Between DIN 931 and DIN 933?
The main difference between DIN 931 and DIN 933 is the threaded section of the bolt. DIN 931 hexagon bolts have a partially threaded shank, whereas DIN 933 hexagon bolts have thread extending over the length defined by the relevant standard.
Diameter and overall length are therefore not the only considerations. The design and technical requirements of the connection also determine which type of hexagon bolt should be used.
What Is the Difference Between DIN 603 and DIN 571?
DIN 603 and DIN 571 are designed for different types of timber fixing. A DIN 603 carriage bolt passes through the materials being joined and is normally secured with a nut. A DIN 571 wood screw or coach screw has a wood thread and is driven directly into suitable timber.
For a through-bolted timber connection, a DIN 603 carriage bolt may be appropriate. For certain direct fixings into timber, a DIN 571 wood screw may be the appropriate choice, subject to the requirements of the construction.
Carriage Bolt or Coach Screw: What Is the Difference?
A carriage bolt and a coach screw are different types of fastener. A carriage bolt DIN 603 has a rounded head and square neck and is normally used with a nut. A coach screw DIN 571 has a hexagonal head and wood thread and is driven directly into timber.
In British English, DIN 571 is commonly referred to as a coach screw. The term coach bolt may also be used for a DIN 603-type fastener, so checking the DIN number and product design helps avoid confusion.
Galvanised or Stainless Steel Bolts?
The choice between galvanised and stainless steel fasteners depends primarily on the application and environmental conditions. Both provide corrosion resistance in different ways.
Galvanised Steel
Galvanised steel has a zinc coating that helps delay premature corrosion of the underlying steel. It does not make the steel completely rust-proof. Moisture, weather exposure and other environmental conditions should therefore be considered when selecting the fixing.
Stainless Steel
Stainless steel offers high corrosion resistance and is used for many applications where moisture is an important consideration. Not all stainless steel grades provide the same properties, so always check the individual product specification.
What Do DIN 571, DIN 603, DIN 931 and DIN 933 Mean?
DIN references identify standardised characteristics of different types of fastener. They help distinguish between the design and specification of bolts and screws.
- DIN 571: hexagon-head wood screw or coach screw for certain timber fixings.
- DIN 603: carriage bolt with a rounded head and square neck.
- DIN 931: hexagon bolt with a partially threaded shank according to the relevant standard.
- DIN 933: hexagon bolt with thread according to the relevant standard.
A DIN reference alone does not establish whether a fastener is suitable for a particular structure. Material, dimensions, mechanical properties and the technical requirements of the project must also be considered.
How Do You Choose the Correct Bolt Size?
The correct diameter and length depend on the type of connection, the thickness of the materials and the requirements of the structure. For a through-bolted connection, also allow for the nut, washer and any other components forming part of the assembly.
Before ordering, check:
- the type of bolt or wood screw;
- the DIN reference;
- diameter;
- length;
- thread type and threaded length;
- material and finish;
- compatible nuts and washers where required;
- indoor or outdoor use;
- the technical requirements of the connection.
How to Install a Bolted Connection
Before installation, make sure the bolt, nut, washer and materials being joined are compatible. The exact installation method depends on the type of fixing and the construction.
- Determine the type of fixing required.
- Select the correct diameter and length.
- Check the material and finish.
- Drill a suitable hole where required.
- Install the bolt or wood screw according to the connection design.
- Fit a compatible nut and washer where required.
- Tighten the fixing using suitable tools.
- Check the completed connection after installation.
For structural or safety-critical connections, always follow the relevant technical specifications, installation instructions and engineering requirements for the project.
Bolts for Timber Structures and Fencing
Timber structures, fencing, pergolas and other garden projects require different fasteners depending on the type of connection. DIN 603 carriage bolts can be used for various through-bolted connections, while DIN 571 wood screws are suitable for certain direct fixings into timber.
For outdoor applications, moisture, weather exposure, timber species and combinations of different materials should also be considered. The material and finish of the fixing should therefore be selected for the actual application.
Buy Bolts and Wood Screws from Intergard
At Intergard you can find bolts and wood screws for timber, building, fencing, assembly and garden projects. Go directly to the type of fixing you need:
For other fixing products, browse our complete fasteners range, including threaded rods and nuts, chipboard screws, wall plugs, hammer fixings and nails.
Frequently Asked Questions about Bolts and Wood Screws
Which types of bolts does Intergard supply?
Intergard supplies carriage bolts DIN 603, wood screws DIN 571 and hexagon bolts DIN 931 and DIN 933. Depending on the product, different sizes and galvanised or stainless steel versions are available.
What is a DIN 603 carriage bolt?
A DIN 603 carriage bolt has a rounded head with a square neck immediately beneath it. When fitted into a suitable material, the square neck can help prevent the bolt from rotating as the nut is tightened.
What is a DIN 571 wood screw?
A DIN 571 wood screw is a hexagon-head screw designed for certain direct fixings into timber. In the UK, this type of fixing is also commonly known as a coach screw.
Is a DIN 571 wood screw the same as a coach screw?
DIN 571 wood screws are commonly referred to as coach screws in British English. They have a hexagonal head and a wood thread for direct fixing into suitable timber.
What is the difference between a carriage bolt and a coach screw?
A carriage bolt normally passes through the materials and is secured with a nut, whereas a coach screw is driven directly into timber. DIN 603 is a carriage bolt and DIN 571 is a wood screw or coach screw.
What is the difference between DIN 931 and DIN 933?
DIN 931 hexagon bolts have a partially threaded shank, while DIN 933 hexagon bolts have thread extending over the length defined by the relevant standard. The correct choice depends on the design of the connection.
Which bolts and screws can be used for timber?
DIN 603 carriage bolts and DIN 571 wood screws are used for different types of timber connection. DIN 603 is suitable for various through-bolted connections, while DIN 571 can be used for certain direct fixings into timber.
Should I choose galvanised or stainless steel bolts?
The correct material depends on the application and environmental conditions. Galvanising provides a protective zinc coating, while stainless steel offers high corrosion resistance through its material composition.
Can galvanised bolts be used outdoors?
Suitability for outdoor use depends on the finish and exposure conditions. The zinc coating helps delay corrosion but does not make the underlying steel completely rust-proof.
Do I need a nut with a DIN 603 carriage bolt?
A DIN 603 carriage bolt is normally used as a through-bolt with a compatible nut. A suitable washer may also be required depending on the connection.
Do I need a nut with a DIN 571 wood screw?
A DIN 571 wood screw driven directly into timber does not normally require a nut. Its wood thread provides the fixing within the suitable timber substrate.
How do I choose the correct bolt length?
The required length depends on the thickness of the components and the design of the connection. For through-bolted connections, also allow for the nut, washer and other relevant components.
Does a DIN reference mean a bolt is suitable for any structural application?
No, a DIN reference alone does not establish suitability for a particular structural application. Material, dimensions, mechanical properties and the technical requirements of the project must also be checked.