Door Security Bolts

[MTbowels]

I need to secure an internal, sapele-effect hollow door of the type that is sold cheaply in DIY sheds for the purpose. The door has a solid block fitted on the edge internally to accept door handles etc with the rest of the door being hollow.

I'd like to fit a pair of security bolts to the door that engage into the door frame. The ones I'm looking at are like this:

http://www.screwfix.com/p/era-concealed-door-security-bolts-white-2-pack/4610g

I'd like to know how secure these bolts are: the key is splined and appears to be similar no matter what make bolts I buy. Does that mean that any splined key would fit? Does this splined key allow someone with some ingenuity to open the door with a suitably sized screwdriver if they didn't have the key or do the splines engage in more secure way? Is it feasible to fit these bolts in a door of this type positioned top and bottom as advised or would they better placed around the solid area on the centre edge?

The small holes for the splined key are about the maximum damage I could cause to the door so anything else seems out of the question. The door has to made secure from the outside.

Thank you.

[diddlydo]

The type of door you describe can never be secure! A hefty shoulder or knee will open it in no time at all. You need a proper solid wood door if you want to fit security bolts.

[MTbowels]

The intention is not to make the door resistant to shoulder or knee attacks. I just need a way to stop someone opening the door from the outside to poke around in the room.

Imagine grandparents trying to stop their visiting grandchildren poking around private stuff or a family who have taken in a lodger who need to keep stuff out of sight. This might give you a better picture of the need.

I'm well aware that the door wouldn't withstand attack from a burglar whatever type of lock was fitted.

[Togo]

I think I would just fit a sash lock with key in the door block provided. Or a hasp and padlock with bolts that go right through the door. Those little secret shoot bolts are ok for a sapele fire door but not much cop in a standard hollow construction door. And yes they can be opened with a screwdriver or duplicate splined key.

[The Builder]

Agree with the others, MT. Simplest way is to convert your existing latch set with one of these..........

http://www.handles4doors.co.uk/era-entrance-lock-door-knob-set-satin-chrome.html?gclid=CKbr1ZvswMsCFS8z0wodF_wJmw

You can hide the key then.

You could indeed fit the ones in your link, but I agree they are easily opened with the right screwdriver. If you did fit them, there's no entry available to anyone on the "wrong" side of the door. You simply put the key(splined thingy) hole in one side only.