Small bolts

[Harold_V]

What’s the Imperial size for the 2mm?

5/64" (.07812")
2mm=.07874"

H

[tsph6500]

You can also easily make yourself a set of miniature nut drivers from Allen cap screws. Silver solder them to a stem, and add a handle of your choice such as a simple "T".

A fun little project on a rainy afternoon.

[Greg_Lewis]

You can also easily make yourself a set of miniature nut drivers from Allen cap screws. Silver solder them to a stem, and add a handle of your choice such as a simple "T".

A fun little project on a rainy afternoon.

See post #18 above for pix of these….

[RET]

Hi,

When I need small hex head (or square head nuts & bolts, I use socket head cap screws and machine the head to shape. Since I have the CNC mill, I created a program for hex heads (2 different programs, one for small & the second for larger screws) and it is quite easy to run off as many as I need at the time. With this method, I wind up with the proper looking head (that shows) and a cheap screw that is essentially unbreakable. Where the heads don't show, I just use the cap screw as it comes from the box. Hex nuts are much less likely to break or strip and if you need more strength, just make the nut a little thicker.

When you make model bolts from hex bar stock, you always have to worry about breaking the heads off by applying too much torque. With cap screws, you don't have that worry. I have a stock of cap screws from #0-80 on up to #10-24.

[Harold_V]

Hi,
I use socket head cap screws and machine the head to shape.

RET,
Did you mean hex head cap screws? Seems to me the socket head would eliminate that as a choice. Did I misunderstand?

H

[Kimball McGinley]

I made my thin-wall sockets from hex drive setscrews, not socket head bolts. I just tapped the end of a bar and loctited it in place. For extra clearance, grind off most of the thread O.D.

[partime]

Harold,
I wonder if RET is machining the socket portion away or mostly away and cutting a hex on the material remaining. Usually, a little less than half the head height left and if a guy leaves a small dimple from the hex you could get little thicker head. Just a guess.
T.

[RET]

Hi Harold,

No, I'm referring to the standard socket head cap screws. They have 3 times the tensile strength of mild steel (180 thousand psi vs. 60). While somewhat hard, they are easily machinable with HSS tooling, just use a little slower cutting speeds. I machine the socket away and there is enough material left to put a hex on what's left. Leaving a little of the socket is OK, but if you want the completely standard hex head bolt appearance, you can fill in the socket with epoxy before doing the machining since it is only for looks. The working load is taken by the rest of the screw head.

I'm a practical person; I work slowly and I design and make my own fittings when I need to. By doing that, I can go down one fitting size which gives a more realistic appearance to the model piping on the locomotive or whatever else I'm working on. I've done a lot of work on Big Boy, but there is still a lot left to do. Often life gets in the way and I have to have the right mindset to work on these things but there is a lot of satisfaction when things turn out the way I want them to.

Richard Trounce.

[Harold_V]

Thanks partime and RET. I've machined my share of socket head cap screws for various reasons, but never had considered making them in to hex head screws. In my mind, the socket was too deep, which appears to not be the case. Amazing what one learns after so many years of experience!

I was a tool builder when I operated my humble commercial shop, where the use of socket head cap screws was routine. I still have a generous supply of them, as I used to make purchases by the box.

H

[RET]

Hi,

Thanks Harold. One final bit to add. If filling the socket head with epoxy for appearance, use the metal filled type of epoxy like "liquid steel" or "liquid aluminum" to get the finished appearance you need once all the machining is done. I haven't actually done this part myself, but there is no reason it won't work.

As the rest of you also know, there are lots of other little tricks you learn over time, but I like all the rest of you, started out as a novice; that's why I don't keep secrets from anyone. If you are interested and look at my posts on different subjects, you can see how I do things.

What keeps me going is the profound feeling of satisfaction I get when the job is finished and it turns out the way I intended and even more so when it actually performs the way its supposed to. The little CNC mill is an example of what I mean. It was expensive and a lot of work to make, but it performs exactly the way it is supposed to. It is accurate to less than a thousandth of an inch and with it, the hard things are easy.

Richard Trounce.