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

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

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

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**

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

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

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

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

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

Jason - yes indeed, your post hadn't displayed when I started typing mine...

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

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

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

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

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

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.

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

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

Neil

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.

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

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