I need to buy these in chrome but what are they called and where can I find them please?

[NotDonna]

These are currently brass door lock type knobs at the top and bottom of patio doors. I want to change them to chrome ones but don’t know where to go to find them nor what to ask for. I thought I’d try screw fix or somewhere online first but don’t know what to search for. Please point me in the right direction. Thanks!

Thumb locks?

Are they just door knobs? Or are they locks?

Is there anything outside, or do they just operate from indoors?

Can you paint them?

The nearest thing I can find is a bathroom door deadbolt, like this:

www.ironmongerydirect.co.uk/product/british-pattern-door-rack-bolt-and-oval-turn-polished-chrome-137930

Door stoppers but place at the top?

I’ve bought knobs from a place called Period House Group before and they have loads of different ones. I imagine if you email them they could tell you.

@Ifailed yes, I think your bathroom bolt is good. The other bathroom bolts I’ve seen have a safety catch on the exterior (so you can open with a coin if someone gets stuck inside). There’s nothing on the exterior with these. You twist them and a bolt goes up into the frame (or down fir the bottom ones). Your photo looks more like it. Thank you.
They are probably a bit bigger than a thumb but nothing like a door knob.

I'd be tempted to try some spray paint such as this if you can't find exactly what you have already.

Looks like a thumb turn/thumb latch. Have a look at ironmongery direct

It’s exactly your link! The bolt goes in at a right angle so not actually a bathroom bolt that goes straight through but this ‘rack bolt and thumb turn’ you’ve managed to find! Huge thanks. I’ve now ordered them.