What sort of bolts/screws are these on this Beam Engine ?

[Brian JohnParticipant @brianjohn93961]

I have purchased a Beam Engine off ebay. It runs very badly so I am going to take it apart to see what the problem is and I will paint it too (Brunswick green ?).

1. I do not know what type of bolts these are. can anybody enlighten me ? I have tried both metric and imperial allen keys and nothing seems to fit properly. It was purchased from the United States so I would think it would be imperial.

2. Painting polished brass and aluminium : Should the metal be roughened up prior to painting with etch primer ? What grade of wet/dry sandpaper should be used ?

Edited By Brian John on 07/01/2015 05:35:44

Edited By Brian John on 07/01/2015 05:37:08

Edited By Brian John on 07/01/2015 05:38:17

[Brian JohnParticipant @brianjohn93961]

[JasonBModerator @jasonb]

Look like stainless steel button head socket screws, like you I would assume an imperial hex. Is it the key that won't fir or the head that is getting mashed due to them being tight? Stainless screws are softer so the socket is more easily damaged and if a thread locker has been used they will be harder to turn.

400grit , degrease and then etch primer

[Vaughan Wilson 1Participant @vaughanwilson1]

Bit difficult to see the heads – they look like they could be Pan Head Torx fasteners.

To help ID the type of fastener try the following link and download the catalogue:

**LINK**

[Ian PParticipant @ianp]

If the screws have hex sockets (hard to see in the pictures) then probably you do not have the correct size Allen key. Most keys bought in sets, do not include the oddball sizes that only Americans seem to use.

Where most people stick to imperial keys in 1/32" increments you will find 7/64" and 9/64" on USA manufactured kit.

Ian P

[JasonBModerator @jasonb]

Given that is it a very small engine you may well find you need a 0.050" key which is the size for 2#2-56 UNC button heads. also worth adding 0.035" and 0.027" size sif you don't have them, often used on small grub screws

EDIT. Couple of useful tables at the top of this page that give key sizes for common threads and type of head.

 

Edited By JasonB on 07/01/2015 08:15:13

[David JuppParticipant @davidjupp51506]

Probably rather small – another oddball size I've recently come across in hex keys is 1/20" (1.27mm) – no idea of the origin. This size is included with quite a few hex key sets, so is presumably commonly used somewhere.

 

Edited By JasonB on 07/01/2015 08:14:56

[JasonBModerator @jasonb]

David that will be the 0.050" key I suggested above, also used on BA as well an the american fixings

[RJWParticipant @rjw]

Appear to be Torx fasteners, clearer if you enlarge the photo’s, the top ones on the cylinder appear to be a bit mashed, probably from using a standard Hex key!

John.

Edited By RJW on 07/01/2015 09:01:45

[David JuppParticipant @davidjupp51506]

Jason – yes indeed, your post hadn't displayed when I started typing mine…

[JasonBModerator @jasonb]

Look like hex to me, bottom of cylinder have not been mashed

And square on to the beam ones

Edited By JasonB on 07/01/2015 09:30:33

Edited By JasonB on 07/01/2015 09:35:34

[Neil WyattModerator @neilwyatt]

If you punch a hole in a sheet of thin metal, like a bit of drink can, you can use it to protect the brass while you carefully cut a slot across the ones on top with a junior hacksaw, you should be able to turn them into slot-head screws long enough to get them out.

Alternatively a left-hand drill in a power screwdriver will probably get them out.

Neil

[Brian JohnParticipant @brianjohn93961]

I would prefer to get them out undamaged ie. I want to buy the correct tool for the job.

I think I may have to purchase these : 0.9mm,  1.3mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm

**LINK**

**LINK**

**LINK**

Sorry about the photos but they are definitely hex heads. I thought the photos would be clearer than that.

 

Edited By Brian John on 07/01/2015 10:21:03

[RJWParticipant @rjw]

Some appear to have an extra spline on what would be the ‘Flat’ part of the recess unless they’ve been mashed with a badly fitting key!

Brian, if you’re looking at Torx keys, or even double hex keys, most cordless screwdriver and drill kits come with a selection, might be worth checking there if you have either!
Torx are a common application on automotive products and many domestic appliances!
Your local DIY or motor discount shop will probably have key sets too!

John.

Edited By RJW on 07/01/2015 10:16:25

[Brian JohnParticipant @brianjohn93961]

I am sure that they are NOT Torx keys. I am sorry that the photos were not clearer.

[Gordon WParticipant @gordonw]

I have a small set of "security keys ". These come in a soft plastic case, there are all sorts of keys-hex, torx 3 lobed, etc. All sorts of odd sizes, with a 1/4" hex shank. Not best quality but may be of use, if only for checking sizes, cheap as well.

[martin perman 1Participant @martinperman1]

Gentlemen,

A slight aside, If your having difficulty trying to undo a Hex head thats been "rung" with an allen key get a suitable sized ball pein hammer and using the ball tap on the head of the bolt around the hex, then take your allen key and tap into hole remaking the hex then you will hopefully undo the bolt.

Martin P

[Neil WyattModerator @neilwyatt]

For odd small sizes in the past I've got away with filing down a slightly-too-large allen key.

Neil

[nigel jones 5Participant @nigeljones5]

You might find them a nightmare to get out! We use some very small/odd sizes on our model helicopters, and once tight it is almost impossible to get them out as they sheer/mash. This is because the standard of allen key is very poor! You cant get good ones for lone nor money in the small sizes so we do as recommended above, cut a slot across them and use a blade screwdriver. Best way to achieve this is use a thin cutting disk in a dremmel.

[roy entwistleParticipant @royentwistle24699]

I used to work on American printing machines Often they had grub screws with a recess much like a Torx the only keys we could get came from USA we couldn't buy them in UK Usually on installation I would change for standard allen types A lot of the screws were 10 /32 I seem to recall the keys were called Bristol Keys They were splined but not like Torx

Roy

[Brian JohnParticipant @brianjohn93961]

I have just been informed by the guy that sold it to me that the set screws are 2-56 and 6-32. The button head screws are 5-40. If I can get them out I might replace them with something more functional.

Edited By Brian John on 07/01/2015 17:08:22

[Neil WyattModerator @neilwyatt]

Looking at the design I'd suspect two things above all – poor alignment of the piston rod and excessive pressure from that valve spring, It looks like its been done up so tight all the coils are pressed together so it isn't acting as a spring at all. A stronger spring that can move will be freer than a weak spring 'locked up'' like that.

Neil

[Brian JohnParticipant @brianjohn93961]

The other problem is if I try to replace these screws and bolts then they must be American because they use a slightly different pitch angle (?) on the threads to those in the UK. I have been in this situation before. If I buy screws from the UK then they will probably only go in a few turns and then stop.

NOTE : I never know what they sell here in Australia !

[JasonBModerator @jasonb]

Brian if you want to buy from the UK have a look at that link to Modelfixings I posted on the first page with the hex key sizes they will have all the screws you need for direct replacement.

 

J

Edited By JasonB on 08/01/2015 07:35:34

[Ian S CParticipant @iansc]

Brian, aside from metric screwed fittings, the next most available thread will probably be UNF/UNC, you then might get BSW, and be pushing it to get BSF, and you would be very lucky to get BA. This is just going by what we get this side of the ditch.

Just my personal view is that it would look more in keeping with steam engines if it had hexagon headed bolts, or studs with nuts.

Ian S C

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