Making studs

[Steam Haulage]

This is not really a new subject but I need to understand the methods used by other members of the forum. There is a lot of mentioning of studs, and often Jo's name come into the discussion. However after a read through nearly every occurrence of the word found from the search box nobody has actually described in detail, as far as I can see, a method of making them!
If anyone has done this I would appreciate a note of where I can find a description, or a link.
It may seem obvious but making M3 - M6 sizes is new to me. I am content with 1" Whit and similar but I reckon there must be some challenges at the smaller sizes.

Thanks
JerryNotts   

[Tennessee Whiskey]

I agree Jerry. I think Jo, the master of studding, should start a tutorial thread. And also, how do you determine the size of stud as opposed to a ( God forbid ) a screw or bolt.

Whiskey

[Jo]

 

I use two techniques depending on the size of said beasties (actually there is a third but I don't "go large"  often) . But it is late and I really need to set up a set of photos to explain the processess.

So not tonight boys  .

Jo

[vcutajar]

Looking forward to it.  Maybe I will stop using threaded rods instead of studs.

Vince

[maury]

Y'all, I'm looking forward to this too. I have been using SST ground threaded rod. Would like to make real studs. This method may also be able to be used for making pipe nipples too????

maury

[derekwarner]

Guys....pre threaded rods in many applications do have the advantage of being a rolled thread ....so irrespective of the parent material...the actual tensile strength of a rolled thread is far superior to that of a stud with a machined thread.....

The determination on the number or size of threaded studs is the same as that for bolts....& is based on the UTS of the parent material x the nominated factor of safety.........Derek

[Jasonb]

In the majority of our uses the strength is not such a big issue. Far better to have an equal length of thread on the end that screws into the hole so all studs fit leaving the same amount sticking out which ensures all your studs show the right amount of thread above the nut.

Rolled studding can also be a bit undersize which can allow the part to move about slightly whereas a properly dimensioned stud not only resists the tension on it but also locates the part better in shear.

The fact its also undersize reduces thread engagement so it may be stronger but will be more likely to pull out.

And finally have you seen the price of BA studding.

J

[Jo]

A few basics:

Size of parent material:

Irrespective of the size of the stud you are making never use parent material that is smaller than 3.2 mm (1/8”) diameter. The problem is that as the material gets thinner it bends so even when making the 1.4mm 12BA studs for the DTC I started with 3.2mm material.

Material:

I know some kits come with steel, others with “bronze”: I in the main use 303 Stainless as it does not rust and cuts nicely. Rarely am I using studs in applications where the tensile strength of the stud is an important factor.  (Just in case you are wondering 303 has a better tensile strength than that horrible 304, but only a ¼ of the strength of a high tensile steel – but my models are not expected to be subjected to the sort of high stresses in modern high performance engines)

Stud length

Now for some maths, the length of the stud consists of:

• The material in the thing we are fixing to.
• The gasket thickness (so easy to forget  )
• The cover we are bolting on.
• The washer thickness (if fitted  )
• The nut thickness (this needs to be checked as some manufacturers don’t make to the published standards)
• Plus an additional one and a half threads to make it look right and to take into account that the last thread will not be full hieght as it will be slightly curved.
  

The thickness of the cover plus the gasket should be left unthreaded in the middle of the stud. A piece of threaded material which is threaded all the way is  horrible.

I have a couple of quick look up tables I use to speed things along, sorry  I normally use BA threads, hopefully someone will have a similair table set for American & French (metric) threads.

Jo

[Steam Haulage]

Hi All,
Now I'm glad I asked the question, seems there is some general interest in this subject. I suppose we all need studs at some time in our lives.

Jo: thanks for the tables. It may be obvious but can I assume  that although TPI are imp. that the other dimensions are all mm? We all know the warning phrase about assumptions!

I hope somebody will chime in with some production methods, especially for the type where covers and such like are held by studs which are un-threaded through the cover.

Thanks to all who have commented

JerryNotts

[Jo]

Yes Jerry, TPI are imperial but I work in metric as all my machines are metric 

I did say last night that I was going to go through the processes of making studs. I could provide a written description now but was going to knock up a couple this evening so that I could provide photos to go with it.

Jo

[derekwarner]

Guys....

1. despite the crazy dimensions....BA is a metric thread form 
2. the nominal [minimum] depth of thread engagement is 1.5 x the thread diameter

Jasonb...

3. a stud threaded [or bare] diameter is not designed to provide alignment or concentricity......... but simply to secure a bolted attachment
4. the purpose of a bolted joint is to retain or constrain energy ..............the calculation of strength is critically important

Derek 

[Jo]

Sorry Derek I do not agree with you:

1. The BA thread form is 47.5 degrees, metric is 60 degrees, you cannot use a metric thread cutting tool to cut a BA thread. It is however based around metric measurements.


3&4.

Studs are carefully shaped / designed with gasket and cylinder alignment in mind: This means that it is easier to assemble an engine using studs. If you think about the differences between using studs and bolts for an application it comes down to the means of installation:

A bolt is installed by rotating it into place, this causes both twisting and vertical clamping forces which are increased when the engine’s cylinder comes under load. Because a bolt is having to simultaneously respond to the stretching and twisting moment its ability to secure the head is slightly reduced.

A stud is tightened into place without any direct clamping force applied through the tightening. It can be threaded up to “finger tightness,” and afterwards, when the item it is securing is installed the nut is torqued into place against the stud. The result is that the nut torque provides the clamping force, causing the stud to stretch along the vertical axis without the simultaneous twisting moment.

So a stud provides a move evenly distributed load distribution (and if you are torqueing up your nuts, accurate torque) than is possible with a bolt.

Jo

[b.lindsey]

Good stuff Jo !  Am looking forward to the next chapters too

Bill

[derekwarner]

Jo...
1. With respect I offer the following..............
2. I was not suggesting that BA & any metric thread forms were interchangeable....
3. I simply noted that BA is a metric thread form & based upon "exact multiples of the metric system units" .........Derek

British Association or BA screw threads are a largely obsolete set of small screw threads, the largest being 0BA at 6 mm diameter. They were, and to some extent still are, used for miniature instruments and modelling.

They are unusual in that they were probably the most "scientific" design of screw, with a basis in metric size (the 1 mm pitch and 6 mm diameter of 0BA) and with a mathematical relationship between the 'number' (e.g. 2BA with K=2) and the corresponding pitch, major diameter, and then spanner size. Though originally defined in terms of the imperial units then in use in the United Kingdom, this was deliberately set to be exact multiples of the metric system units, rounded to the nearest thousandth of an inch. This anticipated worldwide metrication by about a century. The design was first formulated in 1884, following a study of Swiss practice and was standardised in 1903.

[Steam Haulage]

I hope I have not opened a can of worms.

All of the answers so far have been most interesting.

To me a stud has 2 threads, one at each end but the middle section is plain round bar, otherwise if it's threaded full length it's 'studding', a Mickey Mouse device.
 As Jo has told us the purpose of the stud is to provide location and clamping force parallel to the axis of the stud itself. When we use studding we are providing a relatively inaccurate location and the 'stud' with its many unnecessary threads is weaker, and tends to stretch both under the tightening torque and in service. It also provides a thinner section at the point where the two faces meet. A correct length stud ensures that no sharp edges are contacted.
Those of us old enough to have maintained their own cars will recall how the cylinder head studs were unthreaded through the head and the washer not only allowed the nut to turn without twisiting the bolt but also would not tighten down unless the washer was in place.

JerryNotts

[Jasonb]

2. the nominal [minimum] depth of thread engagement is 1.5 x the thread diameter

No thread engagement is not how far the stud/bolt or screw is turned into the tapped hole.

It is the relationship between diameter of tapped hole to the major dia and is expressed as a percentage. eg how much flank contack there is not how far the stud is screwed in. If the commercially produced rolled studding is undersize then the percentage engagement will be reduced.

3. I simply noted that BA is a metric thread form

The term "form" relates to the shape of the thread and as BA is not shaped the same as metric it can't be the same form. It would have been better to say something like "BA is a metric based system"

J

[Jo]

Now let’s look at the production methods. First thing is look to use a number of pieces of rod to make these, I normally use 4 or 8 rods and cut studs on both ends. The reason for this is that once you have your lathe tool set up and calibrated (on your DRO/dials) on a quick change tool post if you change tools the chances are you will need to recalibrate the measuring technique.



Tooling: for the smaller studs I use a tailstock die holder, for larger ones I have now moved over to using a Coventry die head but for now let’s focus on using the more normal tailstock die holder. I also use a mandrel handle, sometimes a collet chuck, sometimes a three jaw SC chuck and others a drill chuck fitted in the nose of the lathe.

[

The example I am going to use is some of the 6BA studs I need for the Double Tangye. These are made from 1/8” 303 stainless rod, so the 1/8” will fit nicely into a collet but once they are reduced to 2.8mm they won’t.

Jo

[NickG]

Thanks for the spreadsheet Jo, will come in handy 

[Steam Haulage]

Thanks Jo,

That's just the sort of detail I would value, not only why but also how to achieve the desired result.

Looking forward to the next post.

JerryNotts

[Jo]

So the starting point is to face the end of the rod and turn the threaded part of the stud that is going into the work piece. Why this end? Because this end is normally longer than the end for the nut so gives you more to hold on to later (and if you get overly enthusiastic and put too much pressure on the threaded end when you hold it later and damage the threads they will be hidden in casting). The distance required to be turned down is the length of the required thread, plus the lead on the die (that’s the tapered bit at the entrance of the die that helps you start the thread). We also need to chamfer off the end of the turned section to help the die start, I do this with a file as I do not want to disturb the lathe tool.



This can now be threaded under power if you so desire or as there is not many threads required the mandrel handle can be used. A bit of cutting compound first won’t go a miss and don’t forget to clear the swarf to prevent damaging your next threads.



Now it is worth just running a file over the end to get rid of any new burrs caused by the die then we can take the shank to length. The length is the remaining length of the stud plus a bit for your parting off tool. And don’t forget to get rid of any burrs raised on the outside of the rod otherwise it will not fit back into the collet chuck.



Before we get excited and finish this one we need to do the same on the ends of the other bits of rod:



Now we can part them off, not forgetting to deburr the stock material before disregarding it.



The other half finished stud you can see in my patented (egg) stud tray  is a 2BA/4BA opportunity which you can't buy commercially. Great for when the standard sized nuts look oversized but you have already drilled and tapped to the drawings before you realised how hideous the size specified looks .

Now the second halves.

Jo

[Jo]

Now we have to decide how we are going to hold these to continue. We are limited to the amount of material we have for holding by the same rule we mentioned earlier we need to leave hanging out of the holding device as a minimum not only the length of the top thread but also enough for the lead on the die. As for holding the watchmaker’s trick is to use a drill chuck in the mandrel:



This works well with very small studs  . Last chance to correct the length of the studs… if you are like me they vary a little, it doesn’t really matter (if it is a little) as when they are inserted they need to be fitted to the correct length, you just need enough threads to let that happen. So go and find the file and taper the edge to help the die start. I normally count the threads in to get the correct length, but if you do don’t do what I did on the DT valve rod studs and forget the plus 1.5 threads for the lead otherwise you will find that your nuts bind before you get them where you want them



And repeat for each:




The alternative technique I use for larger studs is to use a Coventry die head. These are wonderful. But not as easy to set up for smaller threads. My Coventry die head has been fitted to a 2MT and fits into the lever fed tailstock on my Prazimat.



In use I close the die head, introduce it to the work and then count the thread turning the mandrel handle. Once I am at the required number of threads (plus 1.5 for the led) I push the tailstock lever and magically the die head lets go and withdraws itself  .


The only other thing I can add is don’t do more than about 8 at a time otherwise it can get boring  .

Jo

[b.lindsey]

I didn't think you ever got tired of making studs Jo, much less bored with them   Thanks for the great write up !!

Bill

[derekwarner]

Jasonb.......

1. I did not invent  the term "thread form" as applied to BA threads ....& I certainly was not here in 1884....
2. however many authoritive references group the words together as below
3. I certainly am not qualified to question the British Association for the Advancement of Science 

Having said this, I quite enjoy using BA fastners in model building......Derek
___________________________________________________________________________________________________________________________________________

"In 1884 the British Association for the Advancement of Science adopted a thread form and series, primarily for use in precision equipment. It was inspired by one used in the Swiss watch and clock industry, and was formerly sometimes called the Swiss Small Screw Thread System; but is now just referred to as the BA series. Like the Whitworth thread, it has a rounded root and crest, but the included angle is 47.5° and the radius was originally 2/11 (0.1818…) times the pitch, but at some later point was changed to 0.18083. The gauge numbers and pitch are related, roughly, by pitch = 0.9 to the power of the gauge number.


Despite the date of origin and the British sponsorship, the BA is a metric series. Not only is it based on the meter, but the thread frequency is specified in terms of round numbers in the pitch sequence, with threads per meter allowed to fall where it may"

[swilliams]

Great thread Jo!

So far I've learnt two things

1) If you are making small studs you need a Cowells lathe
2) If you're pulling the head off your car, notice the proper use of studs, and you should wear a bikini

Hmm, I'll have to ignore these two points. Heading back to my old methods 

Steve

[derekwarner]

Jasonb.......just thinking more about rolled threaded bar & your note......."If the commercially produced rolled studding is undersize then the percentage engagement will be reduced"

This is not the case for the final product....the parent bar stock may well be intentionally undersized, however the rolling process takes from the rich to give to the poor & increases the diameter of the threaded section

eg., an M24 x 3P ISO metric rolled thread formed fastner may be created from bar stock negative of 24 mm diameter, however the final thread sizing & tolerancing is to the appropriate Standard...in this case being ISO 898/1......Derek

[Jo]

2) If you're pulling the head off your car, notice the proper use of studs, and you should wear a bikini

  I thought that you guys were meant to forget things as you got older.

Jo

[Jasonb]

Totally agree with the theory there Derek.

But in practice the majority of commercial studding and small non graded bolts for that matter that the average model engineer buys tends to be of far eastern origin and certainly in my experience a bit of a slack fit. I can get a far better fit by adjustment of the die than using bought in fixings. Even the good quality model engineering fixings that are machine cut are usually to a slacker fit than making your own.

The other reason we are discussing this is that studding in the smaller ME sizes if not that readily available, over here about the smallest you can get is 8BA or M3. If you have  a source for commercially made smaller sizes such as M1.4, M1.6, M2 & M2.5 that would be of use to members who want to use commercal studding.

[Arbalest]

Those of us old enough to have maintained their own cars will recall how the cylinder head studs were unthreaded through the head and the washer not only allowed the nut to turn without twisiting the bolt but also would not tighten down unless the washer was in place.

JerryNotts

I used to work as a Mechanic at a Ford main dealership many years ago and one thing you got hold of as soon as posible was a couple of head BOLTS to cut the heads off so you could use them as temporary studs. A saw cut aids removal once the head is located and a couple of bolts loosely inserted. Not sure about other makes but all the fords I ever worked on only used bolts. One of my old bangers - a Corsair with a Vee 4 engine had double hexagon (12 sided) heads on the bolts, not seen that since but it's been a long time since I worked on cars!

[Steam Haulage]

Ah but those were bolts not screws. Certainly BMC used studs. My current Ford has bolts as well.

JerryNotts

[steamer]

Nice write up Jo!   

Dave

[Jo]

Thanks Bill, Steve & Dave,

I hope some of the other members also found it useful 

Jo

[steamer]

I am sure it will Jo!....I have a small fixed die head with a plethora of different dies....just haven't had a chance to make studding yet...though the die works very well.

I have a bed mounted turret and tooling for SB...but I need to learn the correct way or sharpening the cutting tools for them......some day before I kick off I suspect....

Dave

[IanR]

Ah but those were bolts not screws. Certainly BMC used studs. My current Ford has bolts as well.

JerryNotts

The main reason for us using studs is that the engines we're modelling used studs, because they are much more economical in metal and machining time. Making a 1/2 Whitworth bolt out of 59/64 hexagon or 1 1/16 round means most of it becomes swarf; with a stud and nut, there is little swarf. But these days bolts are machine forged, and Ford doubtless get them cheaper by not buying a few at a time, shrink-wrapped.

Jo, does the drill chuck you use for holding while doing the second end not chew up the thread you've already done?

[Ian S C]

When I rebuilt the Stuart S9, I cheated a bit, to get the correct amount of thread protruding through the nut I loctited the nut on the studs, and used them as bolts so that if anyone in future on removing them, could reassemble them correctly.   Ian S C

[Jo]

Jo, does the drill chuck you use for holding while doing the second end not chew up the thread you've already done?

  If you have machined them correctly the parallel bit in the middle is the same diameter as the major dimension of the thread. So if you graunched the thread you have already made a mess of the nice parallel part and it won't fit in the hole, so best make another one  .

Jo

[ozzie46]

   Thanks Jo. Nicely done and will help a lot of people here.

 Ron

[sco]

2. the nominal [minimum] depth of thread engagement is 1.5 x the thread diameter

No thread engagement is not how far the stud/bolt or screw is turned into the tapped hole.

It is the relationship between diameter of tapped hole to the major dia and is expressed as a percentage. eg how much flank contack there is not how far the stud is screwed in. If the commercially produced rolled studding is undersize then the percentage engagement will be reduced.

3. I simply noted that BA is a metric thread form

The term "form" relates to the shape of the thread and as BA is not shaped the same as metric it can't be the same form. It would have been better to say something like "BA is a metric based system"

J

In the industry I work in 'thread engagement' means the length of thread that is screwed into a tapped hole.  We use the same factor of 1.5xD with two exceptions; if space is extremely tight we use 1.2xD and for tapped holes into cast materials where we use 2xD.

Thanks Jo for taking the time to write this stud tutorial.

Simon.

[Jasonb]

Maybe this is where Model engineering and industry differ, ask most Model engineers about thread engagement and they will refer to the tapping drill dia to give a percentage engagement.

Take a look at something like "Model Engineers Handbook" and there are several pages and tables dedicated to % engagement and not once does it mention thread engagement length.

The BSI even produced a guidance document "Guidance on metric screw threads and fasteners for use by Model Engineers" which again deals with percentages of radial engagement not length.

These percentages are there to help Model engineers get a strong enough threaded joint using hand tapping methods and without the risk of breaking taps in too tight a hole. So as this is a forum of Model making these standards are far more relevant than a standard in industry where threads are machine cut to higher tiollerances which you may want if hanging the wings of an aircraft off the fuslage with the fixings.

J

[Steam Haulage]

As I seem to have started a thread which has found some interest with other members I have ought to pass on a link which I have just found and which has data  for almost every thread I have heard of, and more.
http://www.gewinde-normen.de/en/index.html

I am very appreciative of the information which has been exchanged and from which I have learned much.
My thanks especially to Jo for illustrating and describing the methods she employs

JerryNotts

[sco]

Well GHT talks about lengths of thread engagement in The Model Engineers Workshop Manual and recommends 1.25 to 1.5xD.

I guess if both the tapping hole is too small or the length too great the end result is the same - broken taps as I've recently found to my cost 

Simon.

[pgp001]

A very rough guide to a suitable thread length can be got by measuring the thickness of a nut in the size you are working with.

I said "rough" because it depends on various other factors as well such as materials etc.
It is quite common to find studs with course pitch threads on one end and fine pitch on the other, especially when they are fitted into something like a cast aluminium crankcase.

It always amuses me when we get new design engineers starting work straight from university and they start drawing up things with tapped holes M3 x 25mm deep in 303 stainless, and wonder why the guy from he machine shop throws a dickey fit 

Phil

[tel]

Where possible, I like to bury a stud into the parent piece by dx2.

[wagnmkr]

Thanks one and all for this info. Jo, excellent pics and explanations.

Cheers,

Tom

[Tennessee Whiskey]

Ok you studding gurus. My steam chest cover calls for 2-56 screws. If I wanted to impress Jo, what size stud and nut would I want to produce. It calls for a 3/32 thru hole in the cover as the prints are drawn now for the supplied screws. Sorry for these nasty old imperial measurements.

Whiskey

[Mosey]

OK, Eric, around our way, studs are born not rolled. I don't know about Tennessee!
Mosey

[derekwarner]

Whiskey........your American thread for designation of 2-56 has a major diameter of 0.086" x 56 TPI which is approx. 0.001" smaller on diameter that 8BA  :

Having said that......you could readily access/purchase UNBRAKO 2-56 proprietary Grade 12.9 high tensile screws...being highly toleranced with rolled threads & just cut the heads off   
2-56 taps & dies are readily available....even I have a set from the American Du-BRO model accessary people

If your plans nominate 2-56....why consider metricating down to M2 or going up the 8BA?

I do understand the word....purchase may send shivers for some.....but horses for courses ...you would be getting high quality studs & literally for US$0.xx cents each.............Derek

[Jo]

I do understand the word....purchase may send shivers for some.....but horses for courses ...you would be getting high quality studs & literally for US$0.xx cents each.............Derek

 

And they come in packets of 50+, and you only need a couple ... of each size. And they won't do anything long enough for the valve chest length 

Jo

[Maryak]

2) If you're pulling the head off your car, notice the proper use of studs, and you should wear a bikini

Don't like bikinis much, the extra space is in the wrong place!

[Jasonb]

I suppose that choice is what it all comes down to some choose to make as accurate a model as they can and would never think of using mass produced metric nuts with their flat oversize double chamfer nuts and not finishing the end of a stud to a nice rounded dome.

They also strive to match the nut proportions to those used on the engines of the past which tended to be smaller hex, taller and usually single chamfer. They then use the untreaded part of the stud to make sure they all screw in the same amount which gives the same amount of thread above the nut and finally dome the end of the stud.

I know which I choose. That is the advantage of making things ourselves we can choose the exact sizes and finished look of the part.

[Maryak]

Hi Guys,

After a request from one of the participants, some discussion and some modifications to posts. This topic has been unlocked and we hope that positive and informative posts will continue to advance our knowledge into studding.

Best Regards
Bob

[swilliams]

2) If you're pulling the head off your car, notice the proper use of studs, and you should wear a bikini

Don't like bikinis much, the extra space is in the wrong place!

You make a good point Bob   

Steve

[Alan Haisley]

When making studs, how much clearance occurs on the unthreaded portion? Are they being used in effect as dowel pins to provide location or only rough positioning and support for the part being bolted on?
Alan

[Jasonb]

90% of the time the plain mid section is the major diameter of the thread so you would just have the clearance that your usual clearance drill for that size thread gives.

There are occasions where you also want the stud or bolt (not screw) for that matter to also act as a locating pin, these are often refered to as fitted bolts/studs and would fit into a reamed hole. For example if using 5BA or 5-40 thread the plain shank would be 1/8" into a reamed 1/8" hole. One such use is the fixings holding the two halves of an eccentric strap.

The "support" that a stud gives is a good point. Back when these engines were made and even more so when they were erected on site there were no electric hoists so it was a case of block & tackle or strong men which meant that it wa sfar easier to slide a heavy part onto the studs that try to hold it in position while lining up holes to insert bolts.

A point that did get raised the other day was the "dome" given to the end of the stud.  As most of these period engines we make are 100-150yrs old there were not the standards about then that there are now although Mr Whitworth had introduced his standard thread form buy then. So a lot of the time its best to just study the old photos and engravings and try to replicate the hex proportions and stud ends that we see, as a basic starting point you can't go far wrong with using the current standard on an ISO bolt/screw which gives the radius of the end curve equal to the major diameter of the thread. We can usually do this with a file while the work rotates in the lathe or if you have a lot to do particularly in the larger sizes it may be worth grinding up a form tool.

J

[mklotz]

The "support" that a stud gives is a good point. Back when these engines were made and even more so when they were erected on site there were no electric hoists so it was a case of block & tackle or strong men which meant that it wa sfar easier to slide a heavy part onto the studs that try to hold it in position while lining up holes to insert bolts.

Still true today.  Imagine how awkward it would be to fix a flat if one had to hold the wheel in alignment while inserting bolts.  Studs and nuts make the job easy.

[fcheslop]

All my recent cars and vans use bolts for the wheels and you're right its a pain
cheers

[Steam Haulage]

Marv,
I do not know the practice in the US these days but here the last few cars I have owned had bolts with what seem to be described as radiused seat, where the dome is on the bolt side of the head so that it fits into the recess in the wheel.
See this link http://www.ebay.co.uk/itm/like/320939674201?lpid=83&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=83

Use of  these has proven the correctness of your comment to my entire satisfaction.

Regards, JerryNotts

[NickG]

Yep, most car wheels have bolts these days as do cylinder heads and the like. Studs and nuts seem a much better idea to me though, not least because you don't have to replace studs but with these 'stretch' bolts you have to replace them every time a head gasket is replaced.

[Jim Nic]

A handy thing to make and keep in your wheel bolt equipped vehicle is an extended pin with a thread to match the hub.  Merely insert the pin in one bolt hole, slide one bolt hole of the wheel onto it to locate and support it and fit the rest of the bolts swapping pin for bolt last.  Simples!  (and should be within the capabilities of most here).
But I digress.........

Jim

[fcheslop]

Yep hindsight is a wonderful thing

[pgp001]

A handy thing to make and keep in your wheel bolt equipped vehicle is an extended pin with a thread to match the hub.  Merely insert the pin in one bolt hole, slide one bolt hole of the wheel onto it to locate and support it and fit the rest of the bolts swapping pin for bolt last.  Simples!  (and should be within the capabilities of most here).
But I digress.........

Jim

And a short piece of tube to slip over the wheel stud spanner to give you a bit more leverage, this is usually required after the idiots at the tyre fitting centre have over torqued your bolts. Dont ask me how I know.

Phil

[smfr]

After making some studs for my Muncaster, a couple of questions popped into my head:

• Should the stud bottom out in its threaded hole, or be stopped by the limit of the threads on the stud shaft?
• Is it cheating not to screw the stud all the way down in order to get the perfect 1-1/2 threads above the nut?

Simon

[Jo]

The depth of the hole into which the stud is fitted should be twice the diameter of the stud, the stud should be threaded at the end for 1 1/2 times the diameter of the stud. ( noting that both hole and stud will have the final few threads tapered) The stud should be stopped by the limit of its threads.

There is no such thing as cheating... in the old days people were proud of the engines their companies created and would make sure that there was nothing for another engineer to pick holes in on their engines. The engine drivers were also very proud of their charges and would endeavor to ensure that nothing was a miss on their engines. Having the same number of threads sticking up on every nut (as well as for the reasons mentioned earlier) meant that it was quickly obvious to the driver if any of the fastners was amiss and needed attention... I am sure in the twilight years of the industries when money was tight  maintenance went down hill and as studs needed to be replaced what ever came to hand was used to do repairs, even  bolts.

Jo

[Mosey]

Yep, most car wheels have bolts these days as do cylinder heads and the like. Studs and nuts seem a much better idea to me though, not least because you don't have to replace studs but with these 'stretch' bolts you have to replace them every time a head gasket is replaced.

Perhaps because when they are inserted with a predetermined torque, it ensures the stress on the fastener is correct.
Mosey

[Steam Haulage]

Thanks Jason,

I had forgotten my earlier interest, now revived following my concern with fine threads for which you kindly gave me some starting encouragement.
The thread is older than I recalled.

Regards
Jerry

[kvom]

In past models I avoided making studs other than a few fake ones with threaded rod.  But with my current Muncaster engine it seems mandatory to make them.  If like me you're blessed with a CNC mill then then you can thread mill each end as long as there is a convenient way to hold them vertically on the mill's table.

I will be using drill rod and holding it in a collet vise.  Most of the studs are 1/4-20, 12 for the steam chest cover, 6 for attaching the chest to the cylinder, and 6 more for cylinder to base.

So my process will be to use the lathe to part off all the pieces to length and to chamfer both ends.  Then for each end it becomes a matter of inserting the stud into the collet, move it up to touch the bottom of the thread mill to establish Z0, tighten the collet chuck, and hit the green button.  A 1/2" thread length done in three passes takes a couple of minutes using conservative feeds & speeds.  One thing I did learn from my first few threads is to check it in a tapped hole.  I made pins on which a nut would screw nicely but was too tight for the fit of the tap I am using and/or the starter hole.

It's also possible to make threads smaller than the stock by adding extra passes; for example, 10-32 threads on a 1/4" rod.

For studs and pins smaller than 1/4 I use model scale nuts from American Model Engineering.  I have used their nuts for screws as small as 2-56.  I think that for a 2-56 stud I'd just use threaded rod or cut the head off a screw.  They also can provide model scale screws with hex heads  that look much better then socket heads.