Key Cutting

The keys for my internal garage door (5 lever Yale) are very worn (brass keys, steel lock levers I assume). To the point where they barely operate the lock.

In the current circumstances getting out to get some new ones looks like a challenge and I am reluctant to send photos of the keys together with my address to the online services.

I can get suitable key blanks, and am planning to cut new keys on the mill. However the keys are badly worn, so simple measurement of the depth of cut is not likely to be a success. In extremis I will take the lock out, open it up and do some measurements of the lift needed on the levers.

As the locks are assembled from a limited number of levers I assume that "somewhere" there is a specification that gives the depth of cut needed for each lever in the set, from which I could deduce the original depth of cut in the key. However I can't find such a reference online.

Can anyone point me in the right direction for the specifications?

Thanks in advance.

Why not just buy a new cylinder and keys. If the keys are that worn the cylinder probably is just as worn.

£10.00 or thereabouts plenty of places on-line, this pic from ToolStation

(Of course I am assuming it is the type illustrated and not a mortice lock! In fact a new mortice lock is only £25 from ScrewFix, why compromise on security. )

John

Edited By Journeyman on 10/01/2021 16:58:55

Could be wrong but I get the impression it's a 5-Lever mortice lock or sash lock made by Yale

If so I don't know of the measurements but not too hard to measure the levers once they are apart

Edited By JasonB on 10/01/2021 16:54:57

Yes it's a sash lock (deadbolt plus handle). It works fine except for the worn keys. I could replace it for about £30, but on principle I would rather keep it in service rather than junking a perfectly useable item.

I just wondered if anyone had the data to save me disassembling it to measure.

Thanks.

It may be a lever lock, but to me looks more like a pin-type cylinder lock.

If so, there are two basic types.

In the first, as I think this is, when the key is inserted fully in the cylinder whose tail operates the bolt, each tooth and gap moves a pair of pins in a radial hole, to align the unconnected joint between them with the internal surfaces of the lock body and cylinder, allowing the latter to rotate with the key. The pin ends are rounded or chamfered to ease them across the edge of the hole.

When the key is withdrawn, a spring above each pin pair returns the pins so one of each pair straddles the boundary, keying (in a shaft and wheel sense) the cylinder rigidly to the body.

If I am right about the lock type here, examining the flat along the top of the lock may reveal the pressed-in sealing plugs that retain each spring and pin pair.

(Why a pair of pins, not just a single pin? A lock with single pins would need a key that simply puts the base of each in line with the lock wall - not secure against a fluted strip of constant width beyond the initial ramp. Using two pins ensures that over-height key teeth would make the lower pins straddle the boundary.)

'

In the second , as used to be used on cars , filing-cabinets and the like, the pins are replaced by thin plates; but I am not sure if they work as in the pin type or by emerging to pull an outer cylinder round with the inner, holding the key.

'

I would think if this one does use levers, the principle is essentially the same - but if so you need know the true lift of each lever, as with the pins. I am not surprised you can't find the dimensions on line - it's not something that reputable lock-makers and repairers are likely to publish, for obvious reasons.

You are better off simply buying a new lock and keys. The tolerances on locks and keys are close and though no doubt feasible for your milling, the combinations of dimensions make it hard to know the real dimensions from a badly-worn key, and if the lock is worn as well, the chances of success are even lower.

Places like Toolstation and Screwfix are probably open but by on-line or telephone order preference, and collection at doorway, as in Lock-down 1 last Spring.

'

I have made a key for a pin-in-cylinder padlock whose proper keys were long-lost, by filing a brass-sheet blank to shape (flutes as well). It was a right faff, and more a challenge than a serious proposition. I could do it thanks only to my having read a description of the principle, many years previously!

To measure the key, I polished the lock side (between the curved flanks) to see the brass sealing-plugs against the surrounding brass. The plugs were about 3-4mm diameter, so by very carefully drilling and tapping each M2 I could withdraw them by screw and spacer.

Once I'd laid out each pin pair, spring and plug in order, it was head-scratching time to work out what I had actually to measure and calculate for the pin travels, along with their pitch, cylinder diameter and fluting.

I had no milling-machine at the time. It was all file work. Having filed the flutes so the rectangular blank could enter the stripped cylinder, I profiled each hill and dale, starting I think at the inner end, to make its associated pin-pair rise to the correct altitude. This was with the lock all open so I could measure the depths in progress.

It took a long time, a bit at a time over days, but eventually I had the key work and I could re-seal the pins and springs into their bores.

Was it worth it?

Frankly, no; not least because the one, home-made key would be difficult if not impossible to copy properly on a standard blank in a commercial key-cutting machine. It was a good-quality lock, and I had originally asked a locksmith if he could make new keys. He replied that yes he could, but at a cost far above that of a new lock and pair of keys of similar type and quality. Hence my DIY attempt.

I still have it somewhere but dare not use it, with only one, hand-filed key!

= = =

I digression... One of the simplest but most secure locks I have encountered is a "special", on an equally special door. It consists of a large, stainless-steel screw with a head profiled to fit the unique set of 2 or 3 keys that were made, working inside a long steel tube to engage a hole in the frame; the lot being of welded steel. The lock is reached via a hand-hole in the door, and the screw-head is deep within the tube, so nothing is visible even as a clue from outside. I know it because I profiled the head to fit the key.

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What does, Nigel ?

... Peter hasn’t posted a photo of the lock in question.

MichaelG.

And he has also said it's a sash lock

Union and Chubb do sell keys with a set of new levers but I don't recall seeing them for Yale.

Why not make the first new key 0.010" longer and hand file it back if it turns out too tight. A thin coat of felt tip on the side would show up any tight parts. There is unlikely to be any specification. Check for wear on the stem of the key and the corresponding hole in the lock

Edited By old mart on 10/01/2021 21:18:22

Thanks, that sounds like a plan.

How about building up the worn key with soft solder until it works reliably and then measuring or getting a key cut from it?

Mike

Its many years since I cut keys but first I would take the lock to pieces first and clean it out, do not oil the levers but use graphite to lubricate the lock. The pin of the key come in different gauges, most mortice locks keys are around 5 or 5 1/2 gauge. the first thing we did when cutting keys for locks is to remove the levers (number them in order!) then put the top back on and fit the blank, making sure it shoots the bolt correctly. After that we filed the bit to the correct height, checking for fit.

I was only a 'key cutter' but learnt a few locksmithing skills, last year I master keyed a series of Eurocylinders to fit the house, garage, workshop, potting shed and summer house, keept me amused!

I still have my key cutting manual, if I can find it, there may be a 'proper' description of the proceedure.

Thanks everyone for the suggestions. Looks like it's either strip the lock and measure or a bit of trial and error.

I just assumed that as the steps in other (mostly Chubb) keys are fairly coarse (1.2-1.5mm), and there are firms out there that will cut a new key from a photograph of the old one, that there would be some documented relationship between the lever number and the cut depth. That would allow the key cutter to figure out which lever pattern a photographed key fitted and cut to that pattern.

Ah well the key blanks should be here later in the week so we shall see. The wear on the existing keys seems to be about 0.75mm and they do still (just ) work so I suspect the tolerances will be fairly loose.

Thanks again.

Michael -

Sorry, I mistook the location of the photo, and for some reason the newness of the lock photographed didn't make me look twice.

Jason -

That message, saying it's a sash lock, had not appeared when I posted mine.

Interestingly the concept proposed by the OP was how we used to cut car keys without an original in the 1970's.

Each series,FS, FV, FP etc etc had a set of masters each with a series of notches in set positions down the length of the key all the same depth, but different masters with notches if deeper depths.

The instructions to cut a particular key , say FS 258, were in a folder - cut positions 1, 3, 6 with the No1 master, position 2 with No2 master which was a bit deeper and so on until the key was formed - then repeat fit the other side, different for a 'double safe' key.

Edited By Nick Clarke 3 on 10/01/2021 22:52:40

No problem, Nigel

... as the man said: “All’s well that ends well”

MichaelG.

I found my 1958 copy of the Encyclopaedia of Locksand Builders Hardware Published by Josiah Parkes & Sons Ltd, Union Works, Willenhall, England, and this is how to do it! I don't think I break any copyright laws by pasting a small section for private use, if I do, mods please delete it!

I worked on Chubb 5-lever locks for a local, and very large, church in the 1980s. I still have my technical notes somewhere, but from recollection there were seven different levers available (I don't think they're actually called levers) and they differed by 0.015" from each other. I can dig the notes out if anybody thinks it would be helpful. I agree with what has been said about cleaning the lock and lubricating it with powdered graphite. If it has seen this much use, it deserves some love and attention. The Chubb lock also has a rotating part that you actually insert the key in, and these wear badly and let the key drop. I found that replacing that part would bring several troublesome keys back into operation.

Because I had so many locks and keys to deal with I made a Perspex cover plate for the lock body, which allowed me to see in detail where problems lay within.

George B.

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Yes please, George

MichaelG.

I'm going to plum for this lock being a pin type lock as others have said. If the key has a 5 digit code then that code will enable a key to be got or made. Any good locksmith will be able to help or you could have a go yourself. Each step has a flat at the bottom that the pin will sit in and this is the dimension that matters - measured from the back of the key. A key I have for a garage door has the following dimensions that may help.

The uncut key has a height of 8.4 and a code of 35385 Height 3 = 7.85, 5 = 6.85 & 8 = 5.5 This key is also almost new and original, a new cut key will not have this code. As keys wear it is usually the crests that get worn, not the bottom that matters, especially if you carry them on a bunch in your pocket.

An interesting book on this subject is, The complete Book of Locks and Locksmithing, by Roper and Phillips. ISBN 0-8306-3522-X.

Good luck

Hi Peter.

If it helps I can provide you with the measurements of the peaks, valleys for the shaft axis and widths of a modern (2 year old) Yale 5 lever (BS3621) for you to compare. There are 4 different levels on my steel keys. If you want to PM me. It may save you having to dismantle yours.