Door Bolts

Black PVD Stainless Steel 6" Flush Bolt, from our current range.

What is a door bolt?

A door bolt is a simple mechanical bolt that slides into a keep or hole to secure a door, used either as extra security alongside a main lock, or to hold the inactive leaf of a pair of doors closed and immovable. Bolts are generally split into two types: flush bolts, which recess into the edge of the door for a neat, unobtrusive finish, and surface bolts, which are fixed to the face of the door and are quicker to fit.

Flush bolts are the more common choice on the inactive leaf of French or double doors, since they sit hidden in the door edge, top and bottom, and hold that leaf rigid while the active leaf is used day to day.

Where door bolts are used

• French and double doors – flush bolts, top and bottom, secure the inactive leaf so the active leaf can be locked normally
• External doors – surface-mounted bolts add extra security alongside a main lock, often specified by insurers
• Fire doors – flush bolts are used on fire door pairs to secure the leaf that is not normally opened, working alongside a door coordinator
• Sheds and outbuildings – simple barrel bolts are a low-cost way to secure a door, often paired with a padlock

Choosing the right door bolt

A few practical points are worth checking before you buy:

• Flush or surface fixing – flush bolts need a mortice cut into the door edge, while surface bolts fix directly to the face and are quicker to fit
• Length – longer bolts give a deeper throw into the frame or floor, generally offering better security
• Fire door certification – if fitting to a fire door, check the bolt is approved for that use
• Finish – see our Hardware Finishes Guide to match existing door furniture

Related products

Browse our current range of Bolts, or see the related categories in our Locks & Security Guide and Door Furniture Guide.

Frequently asked questions

What's the difference between a flush bolt and a surface bolt?

A flush bolt is recessed into the edge of the door for a neat finish. A surface bolt is fixed to the face of the door, which is quicker to fit but more visible.

Do I need bolts on a pair of French doors?

Yes, in most cases. One leaf of a pair of doors is usually fixed shut using flush bolts top and bottom, so the other leaf can be locked normally without both leaves moving independently.

Are door bolts fire door compliant?

Only bolts specifically tested and approved as part of a fire door specification should be used on fire doors. Check with us before fitting bolts to a certified fire door.

Back to the Door Furniture Guide, or explore the full Knowledge Centre.