MacNeale Safe Lock Set Screw / Spline Key

I’ve attached links to a MacNeale safe lock that is missing a spline key/set screw meant to hold the dial shaft to the drive wheel. It’s possible the spline key was drilled out or alternatively it’s just missing the set screw. I believe the latter is the case as the bottom of the hole where the set screw would go is threaded on both the dial shaft side as well as the drive wheel inner hole. The hole does have a taper - it’s wider at the top and narrower as it fits into the threads between the drive shaft and the drive wheel.

If someone has a picture of a MacNeale lock with a set screw, can they post a picture as I’m going to need to fabricate one.

I had trouble getting my Imgur pictures to link so I’m just going to post the Imgur URLs.

https://i.imgur.com/xQLoP4h.jpg

https://i.imgur.com/2CDWmqA.jpg

https://i.imgur.com/hmVrVcl.jpg

https://i.imgur.com/VlyKBUd.jpg

https://i.imgur.com/AIRUGFb.jpg

https://i.imgur.com/RwttOVG.jpg

Also, my lock case is stamped M & U 271. Is this the lock type? The top of the case (to which the wheel pack screws in) is stamped 272.

Thank you.

A picture of the set screw is not going to be much of a help as the tapered section of the hole should ideally be matched by the taper of the set screw. If the taper of the screw is greater the screw won't fit into the threaded portion, if the taper is less it will fit in the threaded portion but will have some slop. Matching that from a picture will be a challenge I think. Next the threaded portion which Is likely without any taper may not be anywhere near a standard modern thread size given the era the lock was made. There is no doubt that is the original factory method of attachment and never had a spline key. If I was making one, I would first deal with duplicating only the taper until it is a reasonably close fit. Then work on making just a straight screw to get the threaded portion correct. Then make a complete setscrew from the gained knowledge.

Very interesting, David. Doug's advise is spot on as usual and is exactly how I would approach it. I would bet a testicle that the threads will be Whitwoth threads. At that size it could be possible to retap to SAE threads to make things easier. The thread pitch is 55° for Whitworth vs 60° for SAE and the crests are more rounded. Of course a lathe will be your best friend for this project. I would assume this set screw had a slotted head.

I noticed there is a spring at the left side in the lock in one picture. Is it to assist in retracting the bolt?

My uncle has an old MaNeale Urban safe. I will have to take a look to see if it has something similar. The lock needs service anyway. It is turning a little stiff in old age much like the rest of us. I love the lettered dials. My uncle's is set to L-O-C-K.

Thank you both.

At the risk of sacrificing originality, would there be any harm to tapping the hole using the largest width of the existing hole? I don't think it will compromise the integrity of the exterior of the drive wheel or the dial shaft. I believe 1/4 - 28 will work but I need to find my tap that isn't tapered at the bottom (I think that's called a bottom tap).

I've ordered some brass rod stock which hopefully will arrive in about a week.

David

As long as you are not intending to use that lock in a safe for actual fire or burglar protection. And why would you use an antique collectable when there are lots of used reasonably priced better suited safes easily found. Holding the parts together for tapping might be a challenge. Use of high strength red locktite to hold together and then heat up the parts to around 500 -550 deg. F for around 5 minutes to release. Or just use the locktite to hold them together.

Doug,

I know you said you don’t have a dial but do you happen to know the thread pattern on a MacNeale dial spindle?

I’ve tried my 3/8-24 die on the spindle and it binds (as does a 3/8-24 tap on the inside of the drive wheel).

I don’t have a thread gauge but I lined up my tap (upside down) against the spindle and the thread count seems to match. See attached picture:

Attachment 22487

However, on the spindle, the depth of the threads is shorter, the edges are a bit rounded (worn?), and the angle seems about the same.

Whitworth is 16 tpi while BSF is 20 so I’m thinking proprietary threads - not Whitworth.

Any thoughts are always appreciated.

David

Looking closely at the picture it looks to me like a mismatch starts to develop. What you have I believe are 3/8 British Standard fine threads. Technically Whitworth is only the course threads. I tend to lump them together which is probably wrong. But then, I'm not a Limey (in jest). They are 20 threads per inch. Also set your tap into the threads and see if the mismatch is more obvious. The taper on the tap doesn't help.

Here is a fine thread chart.

https://www.gewinde-normen.de/en/whi...ne-thread.html

Here is a coarse and fine tap and die set as an example. I have run across a lot of Whitwortk threads across many brands of safes and still in the locks when the bodies were changing to standard. So far I have managed with out a set but I really should get one.

https://www.amazon.com/Whitworth-Bri.../dp/B07V2DVKTL

The most common 3/8" seems to be 3/8-30, which is still used by S&G today, the next one 3/8-40 and the third I know of is 3/8-32.

It seems that what you do is dependant on what you can do. If you can single point cut a thread on a lathe, you could likely match the thread with a little work. However lacking that capability use that standard tap and cut the threads deeper. You could then make your tapered portion, drill out the center (do that first before tapering) and insert a section of threaded rod. You wouldn't even have to tap the tapered part. Just take the threads off down to smooth round and silver solder or locktite the parts. Or send me the parts and I will see what I can do.

I guess I am confused here which isn't all that surprising. My MacNeale driver has a root diameter of about .455" so a bit larger than yours. Early MacNeale locks may well have been custom threaded in house, but based off of the Whitworth system. In other words a fine thread rounded peak 55 deg angle. And it may even vary further as at that time odds are you were making all your own tooling. Just recently I had to make some special thread sized screws for a Diebold lock case cover.