Saturday, April 1, 2017

Today's Fastener Question

I have some 1/4"-20 bolts that need to stick out 1.5" above the surface and pass through a 1/4" thick surface.  I want to make sure that the bolt does not go any deeper than 1.5".  I put a nut on the bolt, then a washer and lock washer andwhen I reached correct depth, I screwed the nut to the surface.  My guess is that enough turning force will screw the bolt through the nut.  Is there some form of fastener that I do not know about to do this?

7 comments:

KCSteve said...

You could use two nuts tightened against each other as the stop. If you do that then the bolt is NOT tightened against the surface, just held from going any deeper. Don't know if that would work for you or not.

Unknown said...

My local hardware store sells "spacers", which are essentially cylinders or lenghts of thickwall steel tubing with inside-diameter sized to fit standard bolt sizes such as 1/4"

Unknown said...

http://www.ebay.com/itm/10-Aluminum-1-4-Bolt-Spacers-1-2-ODX-1-4-IDX-1-1-2-long-made-in-the-USA-/112261983914?hash=item1a2355eeaa:g:yzMAAOSwUKxYcX05&vxp=mtr

James Gibson said...

Why not a 1.5 inch deep bushing with a 0.25 inch diameter inner hole. Since I am not sure what your head diameter is, but expecting its a hex head a standard head would be about .45 inches in base diameter. so your bushing would be 0.45 OD X 0.28 ID and 1.5 inches in length. If I am understanding the design correctly.

Now what was said is the simple cheap and not so professional way to do it. The professional way would be a shoulder bolt. You can buy one with a shank diameter of 5/16ths but with a 1/4-20 thread at the end. the threaded section would be .44 inches long, but you should be able to order the bolt with the required shoulder segment length of 1.5 inches. The head would be either Hex or circular with an allen key recess in the top.

Marc C. said...

Is there a reason you couldn't drill the nut and bolt and insert a cotter pin?

Will said...

Is the plate threaded? If so, you already have a double nut setup. A lock washer is not required for this, as the torque of two nuts together more than exceeds a lock washer, and would be counterproductive due to a smaller surface engagement.

If the plate is NOT threaded, you could consider using a locknut, or just loctite the nut with the appropriate type for how permanent it has to be.

If you can't thread the plate, consider a threaded insert.

Clayton Cramer said...

Yes, going into a threaded hole. The nut at the right position does seem to make it adequately immobile.