Carriage Bolts DIN 603 – Galvanised & Stainless Steel Coach Bolts
DIN 603 carriage bolts, also commonly known as coach bolts in the UK, feature a smooth round head with a square section directly beneath the head. The square neck helps prevent the bolt from turning while the nut is tightened, making these bolts suitable for a range of timber connections and construction applications.
At Intergard you can choose between galvanised DIN 603 carriage bolts and stainless steel DIN 603 carriage bolts in a range of sizes.
The galvanised versions are made from grade 4.6 steel and are available with an electro-galvanised or hot-dip galvanised finish. A matching DIN 934 hex nut is included with these versions. The stainless steel versions are manufactured from A2 stainless steel and are supplied without a nut.
Prices in this category are per 100 pieces. Select the required material and finish below, followed by the diameter and length suitable for your application.
DIN 603 carriage bolts for timber connections and construction
DIN 603 carriage bolts are bolts with a smooth, rounded head and a square neck directly beneath the head. In the UK, this type of fastener is also commonly referred to as a coach bolt.
The square section beneath the head is designed to engage with the material and help prevent the bolt from rotating when the nut is tightened. This allows the connection to be tightened from the nut side while leaving a smooth rounded head on the opposite side.
DIN 603 carriage bolts can be used for suitable timber constructions and applications such as roofs, conservatories and gates. The correct diameter, length and material should always be selected according to the particular connection and its intended use.
What is a DIN 603 carriage bolt?
A DIN 603 carriage bolt consists of a threaded shank, a square neck and a smooth round head. The square section beneath the head is one of the defining features of this type of bolt.
When the nut is tightened, the square neck helps prevent the bolt from turning, provided that it is properly seated in a suitable material. This makes it possible to tighten the connection from the threaded side.
Carriage bolts or coach bolts – what is the difference?
Carriage bolt and coach bolt are commonly used names for this type of round-head bolt with a square neck. In the UK, the term coach bolt is particularly familiar, while DIN 603 is useful when identifying the standard and bolt design.
For this reason, you may encounter descriptions such as DIN 603 carriage bolt, DIN 603 coach bolt, round-head square-neck bolt or simply coach bolt when looking for this type of fastener.
Galvanised DIN 603 carriage bolts
Intergard's galvanised DIN 603 carriage bolts are manufactured from grade 4.6 steel. They are available in electro-galvanised and hot-dip galvanised versions.
The zinc coating provides corrosion protection for the underlying steel. The most appropriate finish depends on the application and the conditions in which the fastener will be used.
According to the product specifications, the galvanised versions are supplied with a matching DIN 934 hex nut.
Browse our galvanised DIN 603 carriage bolts to find the required size.
DIN 603 carriage bolts in A2 stainless steel
Intergard also supplies DIN 603 carriage bolts manufactured from A2 stainless steel. These provide an alternative to the galvanised steel versions where stainless steel is required for the application.
The A2 stainless steel versions are supplied without a nut. A suitable nut must therefore be selected separately, taking into account the thread, dimensions, material and requirements of the connection.
View our available stainless steel DIN 603 carriage bolts.
Galvanised or stainless steel carriage bolts?
The choice between galvanised steel and A2 stainless steel depends on the application, environment and other materials used in the connection. Intergard offers the following DIN 603 versions:
- Grade 4.6 steel, electro-galvanised
- Grade 4.6 steel, hot-dip galvanised
- A2 stainless steel
Always check the specifications and supplied components of the individual product, as the material, finish and whether a nut is included differ between versions.
What does the square neck on a carriage bolt do?
The square neck beneath the round head helps prevent the carriage bolt from rotating while the nut is tightened. For this to work correctly, the square section needs to engage properly with a suitable material.
This design allows the nut to be tightened from one side while leaving the characteristic smooth round bolt head visible on the other.
Carriage bolts for timber construction
DIN 603 carriage bolts can be used for a variety of suitable timber connections. Applications identified for these bolts include timber structures, roofs, conservatories and gates.
The correct bolt dimensions depend on the thickness of the materials being joined and the requirements of the particular construction. The nut and any other components required for the connection should also be taken into account.
Coach bolts for gates
DIN 603 coach bolts can be used for suitable connections in gates and similar timber constructions. Their rounded head provides a smooth finish on the head side of the connection.
The required bolt diameter and length depend on the components being joined. Measure the combined material thickness before selecting the appropriate bolt size.
Which size carriage bolt do I need?
The correct carriage bolt size is determined by both its thread diameter and its length. These dimensions must be suitable for the materials and connection being assembled.
When choosing a DIN 603 carriage bolt, consider:
- the thickness of the components being joined
- the required thread diameter
- the required bolt length
- the space required for the nut and connection
- the bolt material and finish
- the conditions in which the connection will be used
Select a length that allows the complete connection to be assembled correctly with the intended nut.
How do you fit a DIN 603 carriage bolt?
A carriage bolt is inserted through a suitable hole in the components being joined and tightened with a nut from the threaded side. The square neck beneath the head should engage correctly with the material to help prevent rotation.
- Select the correct bolt diameter and length.
- Prepare a suitable hole through the components to be joined.
- Insert the carriage bolt through the hole.
- Make sure the square neck beneath the head seats correctly in the suitable material.
- Fit the appropriate nut to the threaded end.
- Tighten the connection correctly for the application.
- Check that the complete connection is properly seated.
DIN 603 and DIN 934 – what is the difference?
DIN 603 refers here to the carriage bolt with its characteristic round head and square neck, while DIN 934 refers to the hex nut specified with the galvanised versions.
The galvanised DIN 603 carriage bolts in this range are supplied with a matching DIN 934 hex nut. The A2 stainless steel versions are supplied without a nut, so always check the contents of the selected product before ordering.
Carriage bolts and other fasteners
Carriage bolts are one of several types of fastener used to create mechanical connections in timber and other suitable construction materials. The correct fastener depends on the materials, construction, application and installation method.
Browse our wider range of fasteners if you need to compare DIN 603 carriage bolts with other fastening products.
Buy DIN 603 carriage bolts
At Intergard you can buy DIN 603 carriage bolts in galvanised grade 4.6 steel or A2 stainless steel. The bolts are available in different dimensions, with prices in this category shown per 100 pieces.
Choose between galvanised DIN 603 carriage bolts and stainless steel DIN 603 carriage bolts, then select the dimensions required for your project.
For questions or larger trade enquiries, please contact Intergard.
DIN 603 Carriage Bolts by Material
Frequently Asked Questions About DIN 603 Carriage Bolts
What is a DIN 603 carriage bolt?
A DIN 603 carriage bolt is a bolt with a smooth round head and a square neck beneath the head. The square neck helps prevent the bolt from rotating while the nut is tightened.
Is a carriage bolt the same as a coach bolt?
In UK usage, coach bolt is a common name for this type of round-head, square-neck bolt. Carriage bolt is also widely used, particularly in product and standards-based descriptions.
What does DIN 603 mean?
DIN 603 identifies the standard associated with this type of round-head bolt with a square neck. It is useful when identifying the required bolt design.
What is the square section beneath a carriage bolt head for?
The square neck helps stop the bolt from turning while the nut is being tightened. It must engage correctly with a suitable material to perform this function.
What DIN 603 carriage bolts does Intergard offer?
Intergard offers DIN 603 carriage bolts in galvanised grade 4.6 steel and A2 stainless steel. Different sizes are available within these versions.
What grade are the galvanised DIN 603 carriage bolts?
The galvanised DIN 603 carriage bolts are specified as grade 4.6 steel. This specification should not automatically be applied to the A2 stainless steel versions.
Are the carriage bolts galvanised?
The steel versions are available electro-galvanised or hot-dip galvanised. A separate A2 stainless steel version is also available.
Are DIN 603 carriage bolts available in stainless steel?
Yes, Intergard supplies DIN 603 carriage bolts in A2 stainless steel. These versions are supplied without a nut.
Is a nut included with the galvanised carriage bolts?
Yes, the described galvanised DIN 603 carriage bolts are supplied with a matching DIN 934 hex nut.
Is a nut included with the A2 stainless steel carriage bolts?
No, the A2 stainless steel DIN 603 carriage bolts are supplied without a nut. A suitable nut must therefore be ordered separately.
What is DIN 934?
DIN 934 refers to the hex nut specified with the galvanised DIN 603 carriage bolts in this range. The matching nut is included with those versions.
What are carriage bolts used for?
DIN 603 carriage bolts can be used for suitable timber connections and construction applications. Examples given for this range include roofs, conservatories and gates.
Can carriage bolts be used in timber?
Yes, DIN 603 carriage bolts can be used for suitable timber connections. The square neck beneath the head needs to engage correctly with the material.
Can coach bolts be used for garden gates?
DIN 603 coach bolts can be used for suitable gate connections. Select the diameter, length and material according to the particular gate construction.
How do I choose the correct carriage bolt length?
Choose the bolt length according to the combined thickness of the materials being joined and the space required to form the connection with the nut. Measure the construction before selecting the bolt.
Which carriage bolt diameter do I need?
The required diameter depends on the design and requirements of the connection. The diameter should therefore be selected according to the application rather than simply according to bolt length.
How do you install a carriage bolt?
Insert the carriage bolt through a suitable hole and tighten it from the threaded side using an appropriate nut. Ensure that the square neck is correctly seated so that it can help prevent the bolt from rotating.
Are galvanised carriage bolts rustproof?
No, galvanised steel should not be described as completely rustproof. The zinc coating provides corrosion protection to the underlying steel, but its performance depends on the coating, environment and exposure conditions.
What is the difference between electro-galvanised and hot-dip galvanised carriage bolts?
They are two different galvanised finishes available within the described DIN 603 steel range. When choosing between them, check the specification of the individual product and its suitability for the intended environment.
How are the DIN 603 carriage bolts priced?
Prices in this category are stated per 100 pieces. Check the individual product for its specific dimensions, finish and supplied components.
Can I order DIN 603 carriage bolts in bulk?
Yes, larger trade enquiries can be submitted directly to Intergard. Include the required material, dimensions and quantity so that an appropriate quotation can be prepared.