Question Regarding Cross Drilled Automobile Hitch Pin
Question Regarding Cross Drilled Automobile Hitch Pin
(OP)
I'm designing a stabilizing hitch pin for trailer and hitch applications, everything is good to go except my supervisor would like it to be cross drilled near the end so that a locking pin may be used. My problem with this is that I think somebody could just come by with a hammer and knock the end off fairly easily. I've attached a picture to allow better understanding. The diameter of the hole you see is 5mm. there is another hole through the center of the top view, which is illustrated with the red lines shown. It also has a diameter of 5 mm. The rest of the dimensions of outer and inner screw thread diameter and distances should be in the picture I've given. From my understanding and just an estimate, there will basically be four sectors connecting the main body of the pin, to the part after the 2 cross drilled holes. The centers won't be connected at all. Each sector is estimated at having an area of around 9-12 mm^2. Could somebody please help me determine which force acting downward in the Y-direction from the end would break off this end piece? Any help is greatly appreciated.





RE: Question Regarding Cross Drilled Automobile Hitch Pin
RE: Question Regarding Cross Drilled Automobile Hitch Pin
RE: Question Regarding Cross Drilled Automobile Hitch Pin
RE: Question Regarding Cross Drilled Automobile Hitch Pin
RE: Question Regarding Cross Drilled Automobile Hitch Pin
2 X 5mm holes certainly removes a major portion of the metal. Do you really need 2 holes and do they need to be 5mm.even 4mm holes would substantially increase the area left.
an end view with both holesmarked would have been easier to analyze, especially if it was overlayed with a fine grid.
Regards
Pat
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RE: Question Regarding Cross Drilled Automobile Hitch Pin
I read 6.91 dia not rad. With 13.8 minor ia, there is plenty left. putting a 45 deg bevel on the end will still help
Regards
Pat
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RE: Question Regarding Cross Drilled Automobile Hitch Pin
Cheers
Greg Locock
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RE: Question Regarding Cross Drilled Automobile Hitch Pin
Regards
Pat
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RE: Question Regarding Cross Drilled Automobile Hitch Pin
If you intend to put a cotter in the hole to keep the nut from falling off, then I would source a castle nut first then size the cotter pin hole based on the available castle nut slot width.
If its actually to keep people from stealing the trailer, I think a locking hitch is probably good enough for keeping the honest man honest. Besides, if somebody wants the trailer bad enough they'll take it regardless of what type of pin you put through that hole.
Parenthetically, I bet hitting the end of a grade 8 bolt till it broke off at the cross hole would deform the threads bad enough that the nut would be hard to remove anyways.
Beat to fit, paint to match.
RE: Question Regarding Cross Drilled Automobile Hitch Pin
If that's the case, you probably dont need two holes through the bolt. And what happens if they were to hit the bolt with a hammer and remove the lock? Would they then have to unscrew the bolt from something in order to finish stealing it?
Using a Nylock nut torqued down will itself provide theft deterrence and vibration-loosening resistance.
Beat to fit, paint to match.
RE: Question Regarding Cross Drilled Automobile Hitch Pin
Mike Halloran
Pembroke Pines, FL, USA
RE: Question Regarding Cross Drilled Automobile Hitch Pin
The purpose is so that a locking hitch can be used for added theft deterrance. Obviously if somebody really wants whatever is on the hitch, they're going to get it. I took a hitch to the shop, cross drilled 2 holes and beat the crap out of it yesterday and it held fine. Like somebody pointed out and I suspected though, doing this will obviously damage the threads then the nut won't be coming off anyways without some serious assisstance.
Thanks for the help guys, I think the design is ok for it's intended purpose, it's really not a whole lot more than just sticking up the equivalent of a "brinks home security" sign in your front yard. If people want something, they'll still get it but the idea that it's there should help deter the lazy ones.