Can't identify anchor bolts - 1949 500HP Elliot 1

[mswitz]

This may not exactly be the right place for the question but what the heck. I am trying to figure out what these bolts are called to locate a supplier. They are hex head 1" x approx 2 1/2" and the shoulder area is machined down apparently so the motor can move a little with all the bolts in but not tightened down. I can't figure out the specific name so I am having trouble finding replacements. Any help would be great!! Thanks a ton...

Mike

 

[wbd]

Are you sure that the bolts are machined down? I have seen that and also that the bolt holes are enlarged to allow for alignment. They may be standard bolts that were taken to a machine shop to be reduced instead of enlarging the bolt holes. Either way there should be dowel pins in place to keep the motor in place.

 

[aolalde]

Consult a "custom made bolts" provider like;

http://www.readyrivet.com/

 

[stardelta]

Your bolts have been whats termed as "Necked", its to allow more movement while the motor is fixed down on the bed to ease alignment. Its a dubious practise as it severely weakens the bolt and widely frowned upon by engineers. Any good machine shop will turn down a standard bolt for you, but my advice is to use standard size items.

 

[Mendit]

I think you may be looking for Shoulder bolts check here. Bolts.

http://www.smithfast.com/shldrblts.htm

 

[jraef]

As I interpret your post, there is an area right under the head that is a smaller diameter than the threads. I'm no ME, but I remember a few things from ME classes I took, and for some reason this tidbit stuck. I have heard that referred to as a "waisted" bolt, and it is done to reduce stress concentration in high fatigue situations. It allows the thread cut to run right to the end instead of having the die taper get in the way as it approaches the head when the bolt is made. Without waisting, if you crank down on the bolt and the part making contact is jammed into the tapered area, it might wear the hole in your part oblong if the metal is softer than the bolt, and it is more expensive to replace the part than to replace the bolt. Search for sources on 'waisted' bolts and you may find what you are looking for.

Shoulder bolts are the opposite, the shoulder is thicker than the threads.

Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[jraef]

To further my point...

http://www.roymech.co.uk/Useful_Tables/Screws/Bolted_Joint.html

Search for the word 'waisted' on that page.

 

[mswitz]

After some further investigating of sorts we have found that the bolts we have are standard bolts and were necked or machined locally (bad idea as you say and since one bolt sheared and the others dont look great) they are waisted bolts or reduced shank bolts. I took this info to a couple motor shops and they conferred so I have found what we need. Thanks to all this was much help!