UKC

I know the thing I need, but not what it's called.

I have a bathroom door with a standard kind of bolt fitted on the bathroom-side surface. The protruding shaft of the bolt is round and, due to the profile of the door jamb, it fits into a hole that was drilled into the jamb (by a previous owner). Over time the hole has become worn and doesn't retain the bolt. I need a way to re-enforce the hole.

What I'm looking for (and I've seen in the past) is a short hollow metal cylinder that fits into the hole. It has a flange at one end that would be flush with the jamb and teeth to hold it in place when tapped-in with a hammer.

What's this thing called?

In reply to Andy Johnson:

Flanged metal parts like that for use with plastic, often with an inner thread on the protrusion, are called an “insert”.

In reply to Andy Johnson:

A flanged collar but I don't think that will get you much further.

Does it really need a flange or would a bit of metal tube do?

In reply to Andy Johnson:

Strike plate

In reply to Andy Johnson:

The part of a lock that the bolt or catch fits into is called a keep. You may find it hard to buy one alone without the rest of the lock so it could be easy to fabricate one yourself.

You could even do a little bodge, filling the hole with epoxy and drilling it out to the size you need.

In reply to wintertree:

Thanks for your suggestion! Using "insert" I found "four pronged tee nuts" on ebay.

They're like the item I remember seeing but the have an interior thread. The right diameter would probably do the job and/or I could drill out the thread I guess.

In reply to elsewhere:

That was another option but there isn't much space so i'd have to recess it. Fiddly.

In reply to Removed User:

Yes. Bit of tube and some filler would do, but I don't have any to suitable tube to hand.

tbh my question was mainly provoked by self-annoyance at not knowing the name of the thing I could picture in my head...

In reply to Andy Johnson:

On my electric guitar there are inserts in the body called ‘ferrules’ which are inserted into holes to hold the end of the strings. I think that’s the name you’re looking for.

Measure the o/d of the bolt and the I/d of the hole and get yourself a short length of aluminium tube off eBay. Cut to length with a hacksaw, and glue it in

In reply to paul_in_cumbria: Does anybody else find themselves sitting in pub toilet cubicles, and wanting to fix the broken locks which seem to be in so many of them?

In reply to paul_in_cumbria:

A ferrule is not quite the same thing. It is a metal ‘tube’ that is crimped onto a wire to typically form a joint between two wires. In the seventies I made a Deadman and used a ferrule to crimp a joint that formed the loop at each end.

In reply to Andy Johnson:

Strike plate / box.

In reply to Andy Johnson:

Could you use a screw in threaded socket?

In reply to Andy Johnson:

I seem to recall non-threaded inserts are called bushings.

If you look at 'insert nuts' which tend to be used for flat pack furniture you might find the right size (M6 or M8?) then drill out the thread? Be neater than a T nut.

In reply to Andy Johnson:

I've done it by cutting a little bit off the end of a 15mm copper pipe and gluing it in (it might have fit snug enough in a 15mm hole without glue but someone had lost all the 15mm drill bits so I had to drill a 16mm hole). You might not have any copper pipe to hand I guess.

In reply to Andy Johnson:

In Glasgow it’s called a “hingmy “

In reply to Andy Johnson:

I think you've found the "T-nut" fixing which is standard kit for fixing the holds on plywood panel climbing walls (ie most modern walls). Next time you can get to a wall (when they open....) take a look at a hole not currently used for a hold. It should have a T-nut in place ready to receive a bolt. All you'll see is the thread. The "four pronged" end is on the reverse side. It doesn't look too neat from that side, and, as you say, the thread is not what you need. It might work, but there may be better options.

Martin

In reply to Andy Johnson:

I like MeMeMe’s solution. But, depending on the diameter of the shaft, maybe a suitable helicoil, epoxy resined into place, would be more exact.

In reply to Mark Edwards:

I think if you were going to do that you may as well fill the hole with resin completely, and then when it's gone off drill a new hole.

The nearest thing I can name to what the OP is describing is a 'striking plate' btw, though I know that isn't quite right.  Here's an example of a bathroom door privacy bolt supplied with a choice of two such thingamabobs that they just refer to as a 'strike':
https://www.screwfix.com/p/union-chrome-plated-tubular-privacy-bolt-60mm-ca...

Given that it's just a privacy bolt, not a security thing, the hole doesn't really need to fit the bolt neatly to any real depth.  It's just there to stop someone opening the door accidentally, not booting it in on purpose. 

A rectangular plate with a circular hole would do, no need for the tubular 'insert' bit.  The maker of this bolt supplies the thing I'm describing here and calls it a 'flat keeper': https://www.screwfix.com/p/smith-locke-flush-bolt-polished-chrome-150mm/316...

Cutting a rebate to recess a rectangular plate neatly flush with the surface isn't difficult to do with a nice sharp chisel.  (All but impossible with a blunt one.)

If the plate is circular it's much more difficult.  In a virgin bit of wood you could drill the big shallow rebate to accept the plate first with a flat-blade bit, then drill the hole to accommodate the bolt using the spot where the point of the flat blade bit went as a pilot.  With the deeper hole already there probably the only neat way to cut a rebate around it to recess a circular plate into would be using a router and some sort of template clamped in place.

In reply to Martin Hore:

Yeah I agree. My memory was playing tricks on me.

A strike plate with a circular hole would probably be best.

Try these:

https://www.seaware.co.uk/products/12-galvanised-rowlock-plate

https://www.force4.co.uk/item/Force-4/Top-Mount-Rowlock-Socket-Chromed-Bras...

In reply to Andy Johnson:

I'd get a flat piece of metal (cut from a copper pipe, for example).  Drill a hole of the right size to take the bolt and two countersunk holes for screws and cut it to the right shape, chisel a little bit out of the frame so that it fits flush and put it in place.

In reply to Andy Johnson:

Since I get the impression you're not much of a maker by inclination I'd keep it simple, repair the hole by drilling out the worn bit and glueing in a piece of dowel, cut it flush and re-drill it for the latch. Or snap a picture of the problem and take it to a proper hardware shop so they can find you the right strike plate to just screw on.

Jk

In reply to Andy Johnson:

You need a keep,

Once you have the keep, mark out its position on the frame with a sharp pencil or even a utility knife(which is what I do) making sure every side including the inner part is marked, then chop out what you need to with a sharp chisel until the keep sits flush, to check for flush. 

In reply to Andy Johnson:

go to your local pub with a knackered door lock and nick the 'keep'

In reply to Andy Johnson:

What might be just the job is one of the round wedges you can get for fitting wooden tool handles - just hammer it into the existing hole, although be cautious of size and not splitting the frame:

https://www.uktoolcentre.co.uk/products/faithfull-hammer-wedges-and-timber-...

Edit - seems they are called French wedges or ring wedges:

In reply to Timmd:

The 13 likes reassures me that this isn't as strange as I thought it might be.

In reply to Andy Johnson:

Thanks for all the useful advice everyone.

In reply to Andy Johnson:

I couldn't find a strike plate with a round hole that matched the diameter of the bolt, so I made one from some two mill scrap metal. Chiseled out a recess for it. It does the job

In reply to jkarran:

Incorrect assumption.