# What thread is this- on a grub screw



## sallytrafic (Jan 17, 2006)

I have lost a grub screw for the terminals of my German manufactured charger. In my gash box I have found a few screws with the same thread.

Its 4.62-4.6mm overall diameter across the threads but the pitch is as near as I can judge 1.1mm so its very coarse for its diameter.

anyone any ideas before I start making one


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## Zebedee (Oct 3, 2007)

Hi Frank

I've got some very similar in my treasures tin.

Can't find my micrometer at the moment (_worrying _8O ) but if you get really stuck I'll check them carefully to see if they would be likely to fit.

Dave


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## gaspode (May 9, 2005)

Nearest I can find would be 3/16 whit.
4.76mm x 1.058mm pitch.

Not very likely in a German charger but if you have a 3/16 whit die it'd probably fit if you used the die clamped tight.


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## chasper (Apr 20, 2008)

I know its German but a 10-24 UNC is very close according to your dimensions.


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## davesport (Nov 12, 2006)

Frank, from your description it's obviously not metric coarse. I would guess at at small UNC, possibly 10-24 UNC. This would be unusual for a German product though.

Major diam 190 thou or 4.82 mm & 24 TPI.

I hope you've got a small lathe 8O 

D.


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## loddy (Feb 12, 2007)

Why don't you cut to lenght one of the screws you have found and then cut a slot in the end , hey presto grub screw

Loddy


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## bigbazza (Mar 6, 2008)

I love this engineer speak, I was an apprentice in 1960 and ended up in the tool room mainly on a lathe.
My little old hand book(Zeus) is on my desk at work so I can't have look at the dimensions given. I'm sure you will have your answer before Monday, if not I'll have look.


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## sallytrafic (Jan 17, 2006)

I found it, and it wasn't nickel plated brass but ferrous and my magnet on a stick recovered it from the depths of the van.

However I have just finished making one out of a brass screw in my gash box using the mark one eyeball and a dremmel, and mine is every bit as good  at only 7mm long my eyes haven't packed in yet  and I made the unthreaded bit on the end that grips the wire :shock:

Still be good to know what thread it actually is. I suppose its not impossible that the terminal are bought in from a far eastern supplier who also supplies the US market.

Lesson for everyone here, if you loosen off a grub screw and remove a wire tighten it up straight away


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## homenaway (Jul 27, 2005)

bigbazza said:


> I love this engineer speak, I was an apprentice in 1960 and ended up in the tool room mainly on a lathe.
> My little old hand book(Zeus) is on my desk at work so I can't have look at the dimensions given. I'm sure you will have your answer before Monday, if not I'll have look.


Wow!   Zeus Book - that brings back memories 

for the uninitiated it was a very thin plastic coated booklet of essential engineering data that fitted in your overall's breast pocket. I wonder when it was first produced?

Mine is in a box upstairs all oily and dog-eared. I think I had to buy one on the first day of my apprenticeship (at Fairey Aviation later Westlands at Hayes Middx) along with a six inch steel rule which I also still have  

Steve


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## sallytrafic (Jan 17, 2006)

bigbazza said:


> I love this engineer speak, I was an apprentice in 1960 and ended up in the tool room mainly on a lathe.
> My little old hand book(Zeus) is on my desk at work so I can't have look at the dimensions given. I'm sure you will have your answer before Monday, if not I'll have look.


My Zeus is to hand but I didn't look at it beyond the metric ones  I thought perhaps that German sparkies might have their own sizes like the oft remembered 5 BA


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## sallytrafic (Jan 17, 2006)

loddy said:


> Why don't you cut to lenght one of the screws you have found and then cut a slot in the end , hey presto grub screw
> 
> Loddy


Yep thats what I did thanks but I also made the smaller diameter fiddly bit that grips the wire.


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## geraldandannie (Jun 4, 2006)

bigbazza said:


> My little old hand book(Zeus) is on my desk at work


Wow! That's a blast from the past!

And you can still get them  :: LINK ::

Gerald


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## bigbazza (Mar 6, 2008)

Now that's a bit rude Gerald to call me a blast from the past  
even if it's true :roll:


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## eribiste (May 1, 2005)

Things move on though don't they, even Zeus books. The oily dog-eared one from your apprenticeship days will have logs and anti-logs in it. The new ones have CNC machine address codes instead because we've all got calculators now and don't need logs anymore!


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## eribiste (May 1, 2005)

Things move on though don't they, even Zeus books. The oily dog-eared one from your apprenticeship days will have logs and anti-logs in it. The new ones have CNC machine address codes instead because we've all got calculators now and don't need logs anymore!


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## chasper (Apr 20, 2008)

because we've all got calculators now and don't need logs anymore![/quote]
Wait till your battery fails, along with all the kids that only know how to work out calculations with a calculator. Have you ever stood at a checkout in a shop when the till was playing up, you offer the correct money but the assistant can't work out simple addition or subtraction.


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## CurlyBoy (Jan 13, 2008)

*what screw*

Interesting to see how many ex engineers on the forum, perhaps we should have a meet and we can chat, toolmaker myself with Rolls Royce(aero engines not cars)
curlyboy


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## spykal (May 9, 2005)

*Re: what screw*



CurlyBoy said:


> Interesting to see how many ex engineers on the forum, perhaps we should have a meet and we can chat, toolmaker myself with Rolls Royce(aero engines not cars)
> curlyboy


Hi

I hope Frank does not mind me diverting his thread a bit... He has the answer to his "thread" problem now so it should be OK and often the best forum threads are those that are sparked of by some slightly off topic note ...so here goes :

I remember my apprenticeship well, it stood me in good stead for the rest of my life ...it taught me so much more than just engineering. In those days life on the factory floor as an apprentice was a case of it "makes you or breaks you" and I think my wife may have married me for the fringe benefits that an engineer can give ... we always do things "right" ... I do of course mean we can fix and repair stuff :lol:

Just to add a bit of interest I have been out to my little workshop and into my apprenticeship toolbox ...yes I still have it :wink: a bit of rust on some things as we were under 3 feet of flood water back in 1998 so apologies for the state of the bits in the picture.....

I am sure many of you made items like these when you were an apprentice The drift was my first piece and as far as I remember it it took me a whole week of filing to create it. Did I case harden it too by packing charcoal around it and heating it up for ages ? the memory fades ... :lol:










Mike

P.S. Oh and yes I still have a Zeus book I keep that near my Myford


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## CurlyBoy (Jan 13, 2008)

*What thread*

Hi mike, yes fond memories of the apprenticeship, and my wife and I actually met there 45 years ago!
curlyboy


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## eribiste (May 1, 2005)

*Toolmakers and all that*

Hi all you engineers,

I currently work with some of our young people who take up apprenticeships in engineering, and they still make the drill drift as one of the early jobs. After all, taper shank drills are still released in the same way. I case hardened mine in "Kasenit", but we don't do that now because of 'elf 'n safety'; fumes and all that.

The toolmaker's cramp is a very useful and effective teaching exercise with a lot of engineering principles wrapped up in achieving the necessary accuracy. A useful tool when finished too.

Chasper mentioned young people not being able to do sums; quite right, a lot can't, certainly not in their heads, and when I produce a slide rule they're fascinated by it and haven't a clue how it could work!


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## bigbazza (Mar 6, 2008)

It's funny you mention drills, I work in electronics now and it seems to amaze the younger guys when I grind one slightly offset to make it drill a slightly larger hole. They think you have to use a sharpening machine or throw the blunted drills away


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