Turning square headed bolts

[Jasonb]

I tend to turn the thread on some round stock, thread and then over to the spin indexer in the mill to square them off. If you work both ends of 2 or 3 lengths of rod you are not constantly back and forth. Also gives nice square corners to the fixings as some square stock can be a bit rounded. Once squared saw them off and then when you have a batch just hold in 3-jaw and face them all off to the length required, a form tool could do that and add any specific chamfer.

GHW sell square nuts in the small metric sizes but they use the standard AF size, I think one size smaller looks better like their hex fixings.

https://ghw-modellbau.de/index.php?cPath=18_21

 

[colby15642]

I concur with your comments about the imperfect corners on commercial square stock. Nice finish on y6ur fasteners!

 

[neil_1821]

Thanks for all the suggestions, greatly appreciated. I will make a start on them at some point, those who are in the UK know how hot it is recently and being in a small stuffy workshop at night probably isn’t the best idea after a long day at work. Hopefully make a start this weekend.

Very nice fasteners Jason, and the square nuts certainly add a little something

 

[bazmak]

I agree,but would use a 4 jaw self centering chuck and hot rolled sq stock depending on availabilty and size
What is the head size. Keep it simple,these alternative ideas would probably work but take as least as long
If a std thread size screw is available can an available and suitable head be used for milling down ?

 

[Wizard69]

I concur with your comments about the imperfect corners on commercial square stock. Nice finish on y6ur fasteners!

Key stock is the key here In order for it to be useful key stock must be of precision size with high quality edges.

How lets consider what the heads of bolts look like in the field. Most show at least some signs of distress so imperfect corners would simply reflect the prototypes.

 

[john_reese]

I have a South Bend 10K with a 4 jaw scroll chuck, bed turret, die hed and lots of chasers. The chasers are all American standard sizes. It is a perfect setup for the job. Do you waant to e-mail me a drawing?

 

[bazmak]

I agree that sq bar with slight rad cnrs and small imperfections would add to the look

 

[TonyM]

If you must make from solid then the only sensible way is to turn from square stock. You can make a simple split collet for holding in 3 jaw. If you are open to other methods then why not just buy standard square nuts and studding. Cut studding to length and a drop of soft solder / loctite to finish. Otherwise buy 1000 from China. Cheap as chips.

 

[abby]

I make dozens of 4BA square heads for my miniature quick change toolposts , I have a Pultra lathe with capstan turret and a coventry die head.
Email me a drawing and I will quote if you like .
Dan.

 

[deverett]

A lot of the answers don't seem to take into consideration the size of the heads or threads required.
Firstly, is square material available in the size required?

If not the options are to mill down a size larger square then hold the newly formed correct size in a square collet, ready to hand or probably more likely home made. The original idea of securing square stock in a drilled hole with set screws could end up damaging the bolt faces.
If that is not a practical solution, then the only other way is to start with round bar and turn that down to the across corner dimension; make lots of bolts with the round heads then hold the embryo bolts by the turned shank and square off the head with an end mill in whatever milling facilities are available. Ditto repeato until the 300 or so (+ a few spare!) are done.

Dave
The Emerald Isle

 

[Richard Carlstedt]

Made lots of square and hex bolts and nuts.
For square head I use precision ground Key stock ( 0-1 ) and a regular 4 jaw chuck.
Center the stock and mark with white paint the space between 2 jaws. Always stop and loosen/tighten only those jaws and you will be fine and it is faster than a collet setup.
I have box tool I made based on a Modeltec Article of about 20 years ago that supports the stock while turning it to size and length, and then you mount the die on a pilot at the front of the box tool and thread the bolt, all without shutting off power. takes only 5-10 seconds , then remove the box tool from the Aloris post and drop in a cutoff tool and you have the bolt.

Rich

 

[Cymro77]

This gets stranger and stranger - I can't wait to see the outcome and path chosen! Unfortunately I have nothing helpful to add, I do like the simplicity of the self centering four jaw chuck and square stock.

 

[DJP]

An option not presented is to do keep it simple. If the square head bolts are cosmetic only then leave them off the model and if they are functional then hex head bolts painted over would not offend me. I doubt that bolt heads are the main design aspect of the model to which the observer's attention needs to be drawn.

Purchasing square headed bolts in a size close enough might also be considered a keep it simple approach.

I too would like to see the final solution chosen by the OP.

 

[pramponi]

I didn’t know you could get square hole collets!

We do have a collet set so this could actually be quite viable if I can find one to fit

Pretty sure Grizzly has them so I'm sure they're common. Also hex.

 

[dnalot]

McMaster-Carr has some square headed bolts down to 10-24, but with a round top flange that could easily be milled off.

https://www.mcmaster.com/#carriage-and-plow-bolts/=1dwa1ux

Mark T

 

[john_reese]

You might be able to do them in one chucking. Use a form tool to shape the corners then part off.

 

[nel2lar]

Neil
Have you entertained the idea of making a square collet and a custom parting tool to finish the head of the bolt. I think the time to be a lot less than the 7 minutes. If is going to make a big difference on your set up.
Good luck, I'll be watching
Nelson

 

[neil_1821]

Nelson,

Yes I have though about making a square collet, and i was intending on profiling the parting of took to finish the shape as it’s parted off. Since most of these bolts are only decorative I’ve decided to just make them an interference fit rather than threading, which I think will save a lot of time.

I’ll update my build thread accordingly when I get round to doing some. Thanks to everyone for the suggestions and advice/offer of help. Greatly appreciated.

 

[larryg]

https://www.amazon.com/dp/B00GWOVW3M/?tag=skimlinks_replacement-20

A friend making a bunch of hex bolts took a piece of drill rod and cut the end into a hollow mill by drilling the hole the size of the bolt shank and cutting the flutes with a dovetail cutter. The OD of the cutter was the size to hold a tailstock die holder;
https://littlemachineshop.com/products/product_view.php?ProductID=2314 . He used stock the size of the bolt head, and a hex collet. With this he went into production. Pull the stock out to the bolt length, turn the OD of the material to size, slip on the die holder and thread to length. Part it off with with a parting tool and spin the head against a belt sander to knock off the corners of the top.

He also informed us that he drilled from the back of the cutter to leave just a small section where the shank was guided to reduce friction.

lg
no neat sig line

 

[nel2lar]

Neil
As small as they are what about a form tool to do both the cylindrical part and the head-part off, all at the same time? Pop them out like popcorn!!!
Nelson