Patio lock - 13mm vs 12.7mm

[OldKettle]

Hi,
I've just bough this lock to fit to an aluminium patio door.

https://www.screwfix.com/p/era-100-...te/2430t#product_additional_details_container

The online instructions say you need a 13mm bit, so I bought one of these

https://www.amazon.co.uk/gp/product/B005KH8AF0/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

The lock has now arrived, and it says that I need a 12.7mm bit.

Looking at the online instructions again, they do say 13mm bit, but then say to drill a 12.7mm hole and fit the ferrule.

http://www.free-instruction-manuals.com/pdf/pa_1758547.pdf

Is the bit I bought any good for this job?

Any thoughts would be much appreciated.

EDIT: This is the back of packet

 

[SFK]

OldKettle
"12.7mm" is a "half inch" drill bit.
Guess that the item is from USA (or can be used in USA) and someone converting from "half inch" drill bit used good and found it is 12.7mm.
But did not consider that that does not exist.

I would use your 13mm drill but, once hole is made pull it out quickly so it does note make hole bigger through friction, and expect ferrule to be a tiny bit loose but perfectly okay.

If worried and wish to convince yourself, drill 13mm hole in a bit of wood and see how well ferrule fits.

In this case wouldn't bother, but if perfectionist go to ebay and search for "Imperial Drill Bit".

SFK

 

[OldKettle]

Thanks SFK.

It turns out that the ferrule fits perfectly in the 13mm hole.

Unfortunately, my drilling was slightly off, so the lock works fine without the ferrule, but doesn't quite slot into place with it.

Is the ferrule purely cosmetic? Does leaving it out affect the integrity of the lock at all?

 

[SFK]

Glad it worked.
Plastic feel is to make hole look pretty and to hide rust if your door is steel, and perhaps to distribute load of lock if door aluminium.
No effect on strength of lock itself.

To test if lock fitted well and incorrect place, unlock door at handle and try and open door by (careful) sliding and lifting of f door from outside. If all firm you have fitted well.

Sfk

 

[crank39]

Purely cosmetic

 

[OldKettle]

Thanks to both of you.

Checked it with handle undone, and all seems firm.

and perhaps to distribute load of lock if door aluminium.

The frame is aluminium. Is the hole at any significant risk of deforming, if forced without the ferrule in place?

Bit frustrated that I didn't get the hole perfect. Put paint on the end of the lock to mark the frame, drilled an initial 3mm hole and then used the 13mm, but still managed to muck it up. Need more practice I guess.

 

[SFK]

Old,
To your "will hole deform if forced without the ferrule in place", depends how forced. But should be okay.
And regarding centering your hole, good that wish to be such a perfectionist, but 'exactly' centering a drill into a pen marked circle is more luck than skill.

If you are truly worried and hole is slightly off (and I would not bother in this case as a bit of a bodge, damaging to bit and a bit unsafe method) put 13mm drill bit back into hole, turn on drill and slightly/carefully push drill bit towards side of hole you wish to make a bit bigger. Drill but will remove a bit of the metal. Do a tiny bit at a time, testing each time. Of course now Ferrule might be a bit loose and need a bit of glue to hold in place.

SFK