My Summit rod stretch gauge has a 1/4-28 by 1 inch socket screw that has a dog leg like appendage on the end to seat in the rod bolt dimple. See picture below.

Any thoughts on what this bolt is called and I where I could buy one that's 1 1/2" inches long?

 

You can get a bolt/screw for cheap at the hardware store. If you have a friend with a lathe, you can turn the nipple on. Or, take both the a machine shop and they will duplicate it.

 

I would look at McMaster Carr they carry a lot of fastners. I do not know how accurate it needs to be but instead of turning the end of the bolt down, could you drill a hole in the end of a bolt and use a dowel pin as the nipple???

Don W

 

As stated most hardware stores would carry a wide variety of socket head bolts. Tractor supply always has a stock on hand.

 

Can you show a picture of the end with the pin in it ? You might be able to pull the pin out and get a longer one instead of getting a longer bolt. I doubt you will find a screw with the pin already in it.

That being said it might be easier to just get a set of longer points for the dial indicator.
https://www.mcmaster.com/dial-indica...ce-indicators/

 

I had a problem finding bumper bolts that were long enough when I had my 54. I bought some 1/2 inch allthread and cut a short pience. I put the bolt and the althread in my vise and took my Mig welder and tack welded them together. I don't know if that would work in your application or not.

 

The bolt in the picture appears to be just a commercial allen-head capscrew with a pin pressed in the end of it. You'll need a lathe to accurately bore a hole in the replacement.

 

Just so you guys know what he is working on:

 

Thanks Bill, that visual helps a lot. As mentioned, a lathe is the most accurate way to replicate that configuration. If you have a drill motor and a bench grinder, you could chuck a bolt up in a drill and grind a taper point on the end of the bolt. It would look different, but still provide a small contact area and serve the same function as the fancy bolt tip.

 

I suspect the pin on the original bolt is hardened. Not sure how much that might matter for this application. Good point though, that all this stretch gauge really needs is a centered point on the end of the bolt.

 

I think when its all said and done it would be easier to buy a set of tips for the indicator and be done with it. Not sure why he needs a longer bolt anyway. The tool is adjustable to fit any bolt I can think of. I have the ARP version.

 

I'm not sure how to do a radius on lathe.

 

They make a radius tool for doing it.

 

Oh. That looks like it should work. Thanks.

 

A machinist could file and shape the radius with abrasive paper, using a radius gauge to confirm the radius.

 

It needs to be pretty precise and repeatable because it fits in a "dimple" in the rod bolt.

 

I think a "skilled machinist" (not a machine shop guy) could duplicate it using a radius gauge set. I assume you mean less precise than checking it on an "Optical comparator".

 

FYI - Super tight clearance with the nut and the rod. (bolt bottomed out)
I'll probably remove the nut and just blue loctite the screw into the fixture.
It would have been better if they used a 1 1/2" bolt.

 

Closeup of bolt end.

 

That is tight. The ARP tool has a lot longer tip on that end.

 

cut the head off it,grind a slot in it and use a screwdriver to run it down lock with lock nut

 

Mill the block enough to screw the "Jam nut" onto the bolt higher.

BillK.... Thats a nice unit, easy to handle and rigid.

 

Now, y'all are brainfvcking it to death. Look at the ARP tool: it's just a point on a bolt. You could do that with a drill and a bench grinder. BUT, some people aren't happy unless they spend a bunch of money and overcomplicate things.