# slot cutting in heavy bolt help



## feralfreak (Jul 29, 2008)

for a project im working on(cant give too many details, but its perfectly legal) i think i need to cut a slot in a really heavy bolt, i think it is off a big truck or a plane or something, not from the end to a certain point but about an inch in length right in the middle, maybe a quarter inch wide(the slot), what are my options for doing this if i dont go to a metal working/machine shop?


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## oh'mike (Sep 18, 2009)

A bolt of that size may well be hardened and tempered----so a milling machine may be required-----

Do you have a drill press available to use?


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## joecaption (Nov 30, 2011)

Hmm, not willing to tell us what your planning on doing with this bolt.
Weaking it to the point it could fail if installed in the wrong place.
Simple job but I think I'll pass on this one.
I think it could be called aiding and abeting.


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## oh'mike (Sep 18, 2009)

Joe---this member likes to invent things----He's been around long enough to give him the benefit of a doubt----


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## Bondo (Dec 8, 2007)

feralfreak said:


> for a project im working on(cant give too many details, but its perfectly legal) i think i need to cut a slot in a really heavy bolt, i think it is off a big truck or a plane or something, not from the end to a certain point but about an inch in length right in the middle, maybe a quarter inch wide(the slot), what are my options for doing this if i dont go to a metal working/machine shop?


Ayuh,.... With so Few details, a 4" angle grinder, or a blue-tip wrench comes to mind...


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## feralfreak (Jul 29, 2008)

joecaption said:


> Hmm, not willing to tell us what your planning on doing with this bolt.
> Weaking it to the point it could fail if installed in the wrong place.
> Simple job but I think I'll pass on this one.
> I think it could be called aiding and abeting.


 there is nothing illegal about it, and oh'mike is right, i am trying to invent something, im not trying to sabotage anything, one thing about an inventor is not wanting to get down into details of the thing being invented, at least without a patent to protect it first. the thing this bolt going in is NEVER going into a place one would normally put it so weaking it isnt a concern. i can see where you are coming from but its nothing like that, my mamma raised me right.


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## feralfreak (Jul 29, 2008)

oh'mike said:


> A bolt of that size may well be hardened and tempered----so a milling machine may be required-----
> 
> Do you have a drill press available to use?


yeah i have a small delta drill press









this is the bolt i want to cut a slot in, i found it when i was pulling weeds, a few years ago(when i was pullng them and soon after a tenant we had here moved out while we were out of town), i guess the tenant tossed it or lost it or something but i figured it could be usefull, for scale i put something in the pic for an idea of the size im working with


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## Thurman (Feb 9, 2009)

Look at the head of the bolt to determine the class (strength) of the bolt. Most larger bolts are actually case hardened a few thousands of an inch deep, the rest of the bolt may have high tensile strenght but metal can be removed. Clean the bolt good to remove any residual greases/oils and such. If you don't have some toolmakers ink, use a magic marker to color the section of the bolt you want the slot in. Scribe lines along the area you want the slot, basically outlining the slot. Drill holes just a bit smaller than the width of the slot you want and as close to each other as possible along the length of the slot. Then use a round or square file to remove the rest of the metal from the slot. I have done this many times.


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## Hardway (Dec 28, 2011)

feralfreak said:


> yeah i have a small delta drill press
> 
> 
> 
> ...


So this is on a Trident sub?:laughing:


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## feralfreak (Jul 29, 2008)

Hardway said:


> So this is on a Tridend sub?:laughing:


 haha yeah aquaman gets fussy when he cant get his trident:laughing: youd think they would make this in atlantis:laughing:


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## feralfreak (Jul 29, 2008)

Thurman said:


> Look at the head of the bolt to determine the class (strength) of the bolt. Most larger bolts are actually case hardened a few thousands of an inch deep, the rest of the bolt may have high tensile strenght but metal can be removed. Clean the bolt good to remove any residual greases/oils and such. If you don't have some toolmakers ink, use a magic marker to color the section of the bolt you want the slot in. Scribe lines along the area you want the slot, basically outlining the slot. Drill holes just a bit smaller than the width of the slot you want and as close to each other as possible along the length of the slot. Then use a round or square file to remove the rest of the metal from the slot. I have done this many times.


 do i need to use any kind of a lubricant where the bit touches it?


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## jeffsw6 (Oct 28, 2012)

If you oil the drill bit it will help to cool it. If the bit overheats, you know what happens, it will break and debris will fly. I wear gloves and face protection when I do anything like that. Just imagine you're welding, because if the bit breaks, you will get those flying hunks of hot metal.


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## feralfreak (Jul 29, 2008)

jeffsw6 said:


> If you oil the drill bit it will help to cool it. If the bit overheats, you know what happens, it will break and debris will fly. I wear gloves and face protection when I do anything like that. Just imagine you're welding, because if the bit breaks, you will get those flying hunks of hot metal.


what oil should i use for this? and how do i keep the oil in place? do i need something to help guide the bit?


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## joecaption (Nov 30, 2011)

Even if you had a milling machine there's no way your going to be drilling into that bolt on the side. The bits just going to bend.
Hold it in a vice and use a right angle grinder with whatever width blade you want the slot.
Should take about 1 min.


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## SeniorSitizen (Sep 10, 2012)

We don't know at this point how precision this needs to be, nor width and length, so I'll suggest this. Clamp the bolt to the drill press table using the bolt head and nut flats to your advantage. File a flat in the area to be slotted that parallels the head and nut flats. If the nut is larger than the head, shim the head so the bolt shank is level. As mentioned, lay out the area with lay out blue ( Prussian Blue ) for a good reference. Center punch in a straight line the area for the holes to be drilled and clamp the bolt to the table for each hole to be drilled with a good quality sharp under sized bit. Finish rough cutting the slot with a Dremel and reinforced cut off wheel. If precision is needed, finish filing to the lay out lines. Any inventor should be able to to this with ease. :thumbsup:


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## feralfreak (Jul 29, 2008)

Fairview said:


> We don't know at this point how precision this needs to be, nor width and length, so I'll suggest this. Clamp the bolt to the drill press table using the bolt head and nut flats to your advantage. File a flat in the area to be slotted that parallels the head and nut flats. If the nut is larger than the head, shim the head so the bolt shank is level. As mentioned, lay out the area with lay out blue ( Prussian Blue ) for a good reference. Center punch in a straight line the area for the holes to be drilled and clamp the bolt to the table for each hole to be drilled with a good quality sharp under sized bit. Finish rough cutting the slot with a Dremel and reinforced cut off wheel. If precision is needed, finish filing to the lay out lines. Any inventor should be able to to this with ease. :thumbsup:


center punching didnt occur to me, but im thinking that is a good idea, it should have leaped to my mind, i do it all the time in woodworking


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## SeniorSitizen (Sep 10, 2012)

feralfreak said:


> what oil should i use for this? and how do i keep the oil in place? do i need something to help guide the bit?


Don't use lubricating oil. Water would be better than lube oil. Cutting oils specifically for this type of work are available in liquid or aerosol at most automotive stores. Just an occasional drop every second or two on that size project will do.


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## Thurman (Feb 9, 2009)

That sure looks to be about a 12-13 x 3" hex head bolt to me, or close. I work for a major player (the Blue one)  in the nut/bolt industry and I would not consider that to be a "really heavy bolt", although it may be to you.  Consider that I recently ordered twelve (12) three inch (3") x twelve inch (12) hex head bolts, that's 3-4x 12" grade 8 for a local industry. Oh yeah, the nuts, flat washer, and lock washers also. I'm still doubting, especially after the photo, that this bolt is hard, or even tough. Being as it is smaller than I had originally thought I am sure you can put the slot in it with the method I mentioned. At this time I am currently working on a quote to supply six (6) "tie bolts" for this industry for one of their machines which will be eight feet (8 ft.) long x eight inches (8") diameter and threaded with a twelve thread pitch on each end. That's one bolt.  IF I get this bid then we will supply them for all six (6) of their paper machines. Maybe enough commission for a vacation?


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## joecaption (Nov 30, 2011)

Want to know how hard the bolt is? Just look at the head of the bolt.
How many lines are on it?
Only place you can drill a round bolt is dead center. Even then you would need a center punch or a combination countersink and drill.
It would still be useless to put just a notch in it.
A Dremal is a toy, if that all you have and you have plenty of time have at it.
Any real cutting fluid for metal will have sulfur in it.
Just using water can work harden the bolt.


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## feralfreak (Jul 29, 2008)

Thurman said:


> That sure looks to be about a 12-13 x 3" hex head bolt to me, or close. I work for a major player (the Blue one) in the nut/bolt industry and I would not consider that to be a "really heavy bolt", although it may be to you. Consider that I recently ordered twelve (12) three inch (3") x twelve inch (12) hex head bolts, that's 3-4x 12" grade 8 for a local industry. Oh yeah, the nuts, flat washer, and lock washers also. I'm still doubting, especially after the photo, that this bolt is hard, or even tough. Being as it is smaller than I had originally thought I am sure you can put the slot in it with the method I mentioned. At this time I am currently working on a quote to supply six (6) "tie bolts" for this industry for one of their machines which will be eight feet (8 ft.) long x eight inches (8") diameter and threaded with a twelve thread pitch on each end. That's one bolt. IF I get this bid then we will supply them for all six (6) of their paper machines. Maybe enough commission for a vacation?


i measured it to make cardboard or posterboard mockups to see how big the slots should be, the head is 1 7/16s and the shaft is 15/16s, roughly 8 and a half inch long.
those are some big ones, that makes this bolt look like a little one, but other than the ones connecting the collar ties to the rafters in this house, this is the largest bolt ive seen(im wondering what this could have gone in), for this application im not needing it to be really hard, i mainly just need the weight of it, am i reading this right? 8 foot long? ive bought pine boards that long for a bench, that has to take a huge wrench, or green lantern(my favorite dc comic organization) or superman to turn that! that has to cost a lot, i bet that would give a big enough commission for your vacation and your kids college fund



joecaption said:


> Want to know how hard the bolt is? Just look at the head of the bolt.
> How many lines are on it?
> Only place you can drill a round bolt is dead center. Even then you would need a center punch or a combination countersink and drill.
> It would still be useless to put just a notch in it.
> ...


i dont see any lines but i see some letters and numbers, "307A" and under that is "PX"
i was about to ask about dremel tools for this job, ive even looked at some milling bits in a micromark catalog, but i dont know if they would work in a standard bench top drill press


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## Thurman (Feb 9, 2009)

O.K., so you do have a big bolt. The "307A" designates a grade of Stainless Steel (now you have a new problem with machining) the "PX" designates the manufacturer (which I am not familiar with). Some of the off-shore manufacturers use either their two/three letter code stamp or their American customers code stamp. Yes, the tier bars are eight foot long, they will have a 3/4" hole drilled lengthwise halfway the length of the bolt. A heater would be placed within this hole, the tie bar will be heated to expand it. They don't use regular hex type nuts on these, one end is screwed into part of the machine base, and the other end has a special type two piece compression nut. When the tie bar is secured into the tapped hole of the base, passing through other machine sections, the bar is heated, the special nut is secured then there are bolts on top of it which are tightened which pushes the two nut sections away from each other until the bolts are properly torqued.  The heater is turned off and pulled out, the tie bar is cooled which in turn somewhat stretches the tie bar for proper tension.


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## SeniorSitizen (Sep 10, 2012)

feralfreak said:


> for this application im not needing it to be really hard, i mainly just need the weight of it,


Now that we know that part of the puzzle just make it out of a 1x1 square piece of wood and load each end with lead shot to a tenth of an ounce of the weight you need.


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## feralfreak (Jul 29, 2008)

Thurman said:


> O.K., so you do have a big bolt. The "307A" designates a grade of Stainless Steel (now you have a new problem with machining) the "PX" designates the manufacturer (which I am not familiar with). Some of the off-shore manufacturers use either their two/three letter code stamp or their American customers code stamp. Yes, the tier bars are eight foot long, they will have a 3/4" hole drilled lengthwise halfway the length of the bolt. A heater would be placed within this hole, the tie bar will be heated to expand it. They don't use regular hex type nuts on these, one end is screwed into part of the machine base, and the other end has a special type two piece compression nut. When the tie bar is secured into the tapped hole of the base, passing through other machine sections, the bar is heated, the special nut is secured then there are bolts on top of it which are tightened which pushes the two nut sections away from each other until the bolts are properly torqued. The heater is turned off and pulled out, the tie bar is cooled which in turn somewhat stretches the tie bar for proper tension.


 stainless steel, would that mean i would need to go to a machine shop for the slots? compression nut? dang i never heard of that, but there is a lot ive never heard of:laughing:


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## joecaption (Nov 30, 2011)

307A has nothing to do with stainless steel!.
It's just a low grade carbin steel bolt.
Even if it was stainless, stainless is soft.
http://www.pacificcoastbolt.com/site/customer/ASTM-SAE_bolt_markings.pdf


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## Mo Guy (Oct 29, 2012)

I have a mill and I would do it for you cheap if it is not a hard bolt.


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