LOST JEEPS
http://www.lostjeeps.com/forum/phpBB3/

What size Tap do I need for the rear frame rails?
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=1&t=26505		 Page 1 of 1
Author:  scoobysnax [ Tue Nov 13, 2007 12:32 pm ]
Post subject:  What size Tap do I need for the rear frame rails?
I can’t get my screws in for the rear tow hook and I believe I need to re-tap them as they might be rusted out. Does anyone know what size tape I need? It is for the 2 screw holes on the left side rear frame rails that are used for either a receiver hitch or for the rear tow hook.
Author:  tjkj2002 [ Tue Nov 13, 2007 5:54 pm ]
Post subject: 
If I remember right they are M12x1.75.
Author:  scoobysnax [ Wed Dec 05, 2007 2:37 pm ]
Post subject: 
So I couldn't find a 12mm x 1.75 anywhere and ended up getting a 12m x 1.25". Will that work (the 1.25" part) or am I just going to make things worse? I'm pretty sure it's the right diameter but it just won't go all the way through. I figure the rust is probably at the bottom anyway and hope I'll be able to just work the screw the rest of the way through.

Here's the question. The tap is the kind that goes into a drill and not a hand tap which I would have preferred. I only have an electric drill and it doesn't have a clutch. Can I still make this work or I am risking stripping everything out using a powerful drill?

Next question - I've never used a tap before so what is the right technique? Do I have to use lots of force while drilling or do I only want a little bit of force and let the tap pull itself along?
Author:  ATXKJ [ Wed Dec 05, 2007 2:45 pm ]
Post subject: 
I've never seen a Tap that goes into a drill- only kind I've used are manual and it's about 1/2 turn forward 1/4 turn back - with lots of cuttin oil/penetrating lube in the mix. I'd be afraid anything electric will be too fast and will kill the threads.

also 1.75 and 1.25 are different threads
Author:  Jeger [ Wed Dec 05, 2007 2:46 pm ]
Post subject: 
scoobysnax wrote:
So I couldn't find a 12mm x 1.75 anywhere and ended up getting a 12m x 1.25". Will that work (the 1.25" part) or am I just going to make things worse? I'm pretty sure it's the right diameter but it just won't go all the way through. I figure the rust is probably at the bottom anyway and hope I'll be able to just work the screw the rest of the way through.

Here's the question. The tap is the kind that goes into a drill and not a hand tap which I would have preferred. I only have an electric drill and it doesn't have a clutch. Can I still make this work or I am risking stripping everything out using a powerful drill?

Next question - I've never used a tap before so what is the right technique? Do I have to use lots of force while drilling or do I only want a little bit of force and let the tap pull itself along?


That will screw your threads up. I wouldnt use a hand drill with a tap, it would be very easy to break, then you have a piece of hardened steel stuck in your bolt hole :x I would spray some rust remover....liquid wrench or whatever and then some lube and get the right size tap...one with a square end that you could put a tap handle on or at least a crescent wrench. Go slow and back the tap out if you feel much resistance before continuing it will feed itself in, just make sure you dont get it crossthreaded to start with. Take your time.....broken taps really suck.

Check at lowes, they had a decent selection of single taps the last time i went.
Author:  scoobysnax [ Wed Dec 05, 2007 4:04 pm ]
Post subject: 
Lowes website doesn't have it. Also doing some more searching I've now come across 12m x 1.75" in the options of "Fine" or "Corse." Is there a 3rd option I need to know about? Right now I'm just putting my tow hook on but I don't want to screw this up for when I need a receiver back there. Help :(
Author:  tjkj2002 [ Wed Dec 05, 2007 4:51 pm ]
Post subject: 
scoobysnax wrote:
Lowes website doesn't have it. Also doing some more searching I've now come across 12m x 1.75" in the options of "Fine" or "Corse." Is there a 3rd option I need to know about? Right now I'm just putting my tow hook on but I don't want to screw this up for when I need a receiver back there. Help :(
M12x1.75= The "M" is for metric, The bolt diameter is 12mm(not the bolt head size),and the thread pitch is 1.75 threads per milimeter.

There is no corse or fine option for a M12x1.75,now a M12x2 is a finer pitch and a M12x1.5 is corser.You can not use any other size tap(like the M12x1.25) for a M12x1.75 bolt hole or you'll screw up the threads.



And just if your wondering for SAE bolts/nuts-------3/8 13 bolt/tap/nut=3/8" diameter bolt and 13 threads per 1 inch.
Author:  scoobysnax [ Mon Dec 24, 2007 12:57 pm ]
Post subject: 
I finally ordered one. After I tap it, will I need to spray it down with anything to prevent rust from building back up or locking the bolt in place? Right now I'm only using it for a tow hook but down the road I will be putting on a hitch.
Author:  Goglio704 [ Mon Dec 24, 2007 1:38 pm ]
Post subject: 
In metric bolts the pitch number is the distance between threads, center to center, not the number of threads per milimeter. 1.0 is finer thread than 1.5. It is the opposite of SAE when it comes to pitch. A smaller number means finer threads in Metric and coarser in SAE.

http://en.wikipedia.org/wiki/ISO_metric_screw_thread
Author:  Rush345 [ Mon Dec 24, 2007 7:36 pm ]
Post subject:  I recently saw on 2 Guys Garage
They reccomended after drilling the whole out applying cutting liquid to the TAP and using a drill/screw gun to drive it in having all said tools I had reservation in this appplication for the same issues of brakage. They are cheep tap and die but abusing ones tools has never been a desire!!
:shock: :P :twisted: :wink: :lol: :D 8)
Author:  tjkj2002 [ Mon Dec 24, 2007 8:54 pm ]
Post subject: 
Goglio704 wrote:
In metric bolts the pitch number is the distance between threads, center to center, not the number of threads per milimeter. 1.0 is finer thread than 1.5. It is the opposite of SAE when it comes to pitch. A smaller number means finer threads in Metric and coarser in SAE.

http://en.wikipedia.org/wiki/ISO_metric_screw_thread
Wikipedia is widely known for being wrong(any idiot can add/change the info),I'd rather trust a well known auto source.Check out any Chiltons or Haynes manuals on page 0-9(or close to there) and it will break down SAE and Metric bolt sizes.

Just don't want anyone confused.
Author:  Neal [ Mon Dec 24, 2007 9:03 pm ]
Post subject: 
Metric Fasteners
Metric fasteners material, head style, and type are described in a similar manner to US fasteners. However, instead of threads per inch, the metric system uses thread pitch (the length of each thread in millimeters measured along the shaft of the bolt). The thread pitch is written between the diameter and length (both measured in millimeters) and is separated on each side by an X.
Typically the diameter of a metric bolt is preceded by a capital M to designate metric.
Author:  Goglio704 [ Tue Dec 25, 2007 4:08 am ]
Post subject: 
I only cited Wikipeadia because it was easy and correct in this case. I drilled, and tapped Metric for years in another life. 1.0 is finer than 1.5. I don't want anyone confused either.

Image
By goglio704
Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/