Free UK Mainland Delivery

On Orders Over £75.00

5 Star Rating From Our Customers. See Reviews >
International Delivery

We Deliver All Over The World!

Home > Blog > The Comprehensive Guide To Door Bolts

The Comprehensive Guide To Door Bolts


We hope this Door Bolts Guide will help you choose the right bolt for the job! The type of door bolt that you may need will usually be determined by what is to be used for.

There are three main categories:

  • Surface Bolts
  • Flush Bolts
  • Rack Bolts

Surface Bolts

These are commonly used to provide extra security, or to keep Stable Doors together and Slave Doors in place.

Surface Bolts are usually available as ‘Straight’ or ‘Cranked’. Sometimes a Cranked Bolt is called a ‘Necked’ Bolt.

Straight Bolts are used where the surfaces to be secured are flush. Most often used on the door and frame of a pair of inward opening French Doors. They can also be used on the top and bottom of a Stable Door. The bolt is usually fitted to the door with the keep being fitted to the frame.

Cranked Bolts are used where the surface receiving the bolt is at right angles to the door. This typically happens on outward opening doors where the bolt would shoot up into the frame or down in to the floor. These bolts are supplied with a strike plate to provide a neat finish to the hole.

Surface Bolts come in a variety of sizes. The size you need will depend on why it is being used. You also need to take account of the size and weight of the door it is being used on. It is usual for a 4″ (100mm) bolt to be used when securing Stable Doors together. It will also be used on smaller internal doors when the purpose is to keep a door in place rather than for security. On external, large or heavy doors we receommend a 6″ (150mm) or even an 8″ (200mm) bolt. Of course you need to consider the amount of space you have and the dimensions of your chosen bolt.

Flush Bolts

This type of bolt is most commonly used to keep the slave door of a pair of doors in place.

They are usually morticed into the side edge of the door and the bolt shoots up or down into the frame. Operated by either a slide or lever action mechanism that throws and withdraws the bolt. A strike plate is used to provide a neat finish to the bolt hole.

As with Surface Bolts, they come in a variety of sizes and the size and weight of the door is the key factor when choosing the right size. The smaller 4″ (100mm) flush bolt would be used on lighter weight internal doors, a pair of airing cupboard, pantry or wardrobe doors for example. For larger, heavier external doors we would always recommend at least a 6″ (150mm) flush bolt. As always you need to measure carefully to ensure you have a door thick enough to accommodate the size of bolt.

Rack Bolts

Rack Bolts provide added security to external doors. They are usually morticed in to the top and/or bottom edge of the door and the bolt extends up or down in to the frame. Rack Bolts are usually supplied with an Escutcheon to provide a neat cover to the hole made on the face of the door which accepts the Rack Bolt Key. For high use areas you can fit a Rack Bolt Turn. This is a small knob that has the key spindle attached and fits into the bolt and is secured to the face of the door with screws (similar to a Bathroom Privacy Turn).

We hope you have found our Door Bolts Guide useful, but if you need any further information, just give us a call on 01630 647748 or contact us.