Reply With QuoteThey are called grub screws in our industry?
mike
Hi guys,
After 3 years of door knobs constantly falling off, I have decided it is finally time to properly attach them. I can't get them anywhere locally, but have no idea what they are called which makes googling a little bit tricky.
Here is a picture. They are screwed into the threaded hole in the door knob with the bottom bit going into a hole in the spindle. I presume they are fairly old since not easily available (doors are original 1930s in our house, no idea if the handles are though).
They are called grub screws in our industry?
mike
Yep, grub screw.
If you still have them and are not looking to replace lost ones, some thread lock would secure them.
Check to see if the hole in the spindle is threaded. Grub screws aren't usually that shape.
it is not. only the hole in the actual knob is threaded.Originally Posted by PickleB
I would be surprised if you could buy any now, but a friendly engineer or model maker could easily make some.
Or a watchmaker, thinking about it. Anyone with a small lathe.
Alternatively, if you find a couple of screws with the same thread ( looks like one eighth whitworth to me) you could bodge some with a cordless drill and a file.
OK...next question. Can the threaded portion fit into the hole? If not, then it seems you'll need to find someone with a lathe...as has already been suggested.
Just make one yourself, get a fully threaded brass grub and remove the threading to the required size with a file.
It's brass ,it won't take long.
mike
That should work
Bit of threaded brass bar of correct thread size, cut a bit off, turn down on lathe, file screwdriver slot. Easy for a modelmaker/engineer
failing this, a pillar drill or bench mount for your electric drill will do as a "lathe" and then careful use of a file to shape.
Buy a standard grub screw of the right length and thread, then either turn/file the end to fit in the hole, or even easier, use a drill to open up the hole in the bar to take the full threaded diameter of the screw.
Brighty
My old house had these - half of them held on with any old screw. I can't quite remember what I did now but I think I drilled into the handle or the bar so I could put a full length screw in there to retain the handle on the bar - probably after turning the first one down.
BTW you can turn down something like that by clamping in a drill and holding a file on it whilst spinning the drill as a sort of improptu lathe but if it is just the hole in the handle that needs enlarging that is what I would do - and as has been mentioned before loctite.
I just bought some imperial screws from here - very helpful gentleman who had relocated to Greece, they came in about a week.
http://www.stainlessautomotivefastenings.co.uk/
Yup - I agree - a grub screw with an end spigot.
B
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