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[Modern View]
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| Zachary Hoyt
09-14-2012 14:12:21
184.12.64.194
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I have a pair of fast hitch arms that are over 1" thick steel of some kind. They have 3/4" mounting holes in them that I need to bore out to 7/8". I have a floor drill press with a low speed of 200 RPM and I am wondering if I should buy a bit and do this myself or take it over to town and pay probably $15 to have a guy do it. If I should do it myself what type of bit would be correct for this application, and what kind of oil or other liquid should I use, if any? Metal drilling always makes me nervous, so I figured I would see if I could find out how to do it right.
Zach
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| Paul Janke
09-16-2012 07:16:23
216.166.168.54
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| If you choose to use a hole saw, fasten something with a 7/8 hole over the spot where you need the hole. This hole is the guide for the saw, and you won't need a pilot drill.
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| Bradracer18
09-16-2012 07:03:55
173.215.8.237
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| If you take it to a shop, I know what I'd do, I would probably just use an end mill and mill a round hole.
If you aren't taking much, and the depth isn't a lot you can also use an end milll/counterbore to drill these holes.
One thing to pay attention to, if you truely want the right sized hole, when you start drilling a hole, the bit should "throw" 2 spirals of metal. If only 1 spiral, its not sharpened right. If no spirals and small chips, needs sharpened. An unsharp bit can actually make the hole larger. If had to sharpen new bits before too, fairly easy with a disc grinder.
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| 36 coupe
09-16-2012 04:33:13
66.186.169.176
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| You stand a good chanch of having the drill catch or breaking the corners off the drill bit.Have done.
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| GUIDO
09-15-2012 16:40:53
71.168.199.69
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| Hello Zackary Hoyt,
Best tool to use would be a reamer. You are only taking off .1/8 of an inch total. The second choice would be a reamer drill, that maybe an expensive choice, unless you have a bunch fo holes to drill.
Guido.
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| timcasbolt
09-15-2012 16:33:25
72.23.207.250
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| Here's one with free shipping: http://www.ebay.com/itm/7-8-BLU-MOL-BLACK-OXIDE-SILVER-DEMING-DRILL-BIT-NEW-1-2-SHANK-135-S-P-/270954486689?pt=LH_DefaultDomain_0&hash=item3f16255ba1
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| Bob - MI
09-15-2012 16:22:30
24.236.144.198
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| | The $15.00 price is cheap. If you can get it done for that go for it. Drilling metal isn't something to be afraid of. You just have to respect the machine and make sure you have the workpiece clamped properly. If it's long enough you should make sure to hang the end of the workpiece off the back so it can stop against the left side of the column. That way if it grabs the column will stop it from coming around at you. Hole saws won't work to enlarge a hole unless you can rig up a pilot for it. Ideally you need a core drill or a reamer but a standard drill bit will work fine. 200 rpm's is probably slow enough and you should just work slowly and relieve the cut frequently. Any good oil will help keep things cooler. Where are you at? If you were in West Michigan I would have you come to my shop and we would do it for you for free.
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| Stick welding
09-15-2012 07:59:44
96.53.210.246
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| 200 RPM should work fine for just using a 7/8" drill bit. A carbide burr in a die grinder would be a PIA! If it grabs wrong will throw the die grinder all over the place. BTDT Make sure to have the piece centered and clamped really good before you drill it. The first part of the cutting may chatter a bit but will stop after you get the outside edge of the hole established. If a shop will do it for $15, that's cheaper than buying the drill bit if you don't have one.
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| CenTex Farmall
09-15-2012 07:21:05
12.146.230.34
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| | If it really will cost 15 to 20 bucks to farm it out then that is your best bet. I've had similar problems to solve before and if it was me I would use a carbide bur in die grinder. You're only removing a 1/16 on each side of the hole and a carbide bur at high speed will remove a lot of material in a short amount of time. If you have an eye for detail you can make a surprisingly round hole. It will function in an electric drill but will take vastly longer. The HSS burs sold at the hardware store will not do at all! The trick is of course that you will have to buy a carbide burr which will cost 10-20 dollars at your local industrial supply house. The hole saw idea will definately work IF you can make the 3/4 pilot to get it started without walking. I don't think 200 rpm is slow enough for a 7/8 drill and most likely will try to grab while trying cut such a small amount and shatter the edge of the flutes.
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| El Toro
09-15-2012 06:05:32
108.3.143.30
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| We used cutting oil when drilling and be sure to anchor those fast hitch arms when drilling. Hal
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| markiz41
09-14-2012 21:05:06
108.50.6.96
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| I'd get a 7/8 step (uni) bit. Pricey, but it'll act as a reamer, which is really what you want. It'll pick up that 3/4 diameter and keep the drill from walking all over the place. Makes nice round holes too. If it's too short to go 1 inch deep, you can put it on an extension.
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| RodInNS
09-14-2012 20:57:42
216.118.158.123
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| I'd be surprise if anyone would drill them for you for 15 bucks... if if they will, that's no doubt your cheapest route.
Myself... I'd probably just go buy a good quality twist drill of the appropriate size and have at it. Cleaveland is a good drill....
Run it slow and keep lots of heavy oil on it.
I think you'll find that in spite of the rough finish on the arms they're not really all that hard. Drilling shouldn't be too bad.Rod
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| gtractorfan
09-14-2012 18:46:04
71.66.229.3
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| Fast hitch arms? Sounds like you may have some tough steel you'd be drilling. It makes a lot of difference.
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| Bernie/MA
09-14-2012 17:35:44
67.142.166.22
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| I would use a core drill. They usually have 4 flutes. Look for a used one, flea markets, etc. The new one I got from MSC Supply was about $40 30 years ago. I've drilled hundreds of holes with it and have never had to sharpen it.
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| Puddles
09-14-2012 17:20:48
24.113.77.208
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Re: Boring a 3/4 hole to 7/8 in steel in reply to scottsdad, 09-14-2012 14:12:21
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| When ever I need to re-drill a hole I like to use a roto broach. Just find center of the original hole, little thread cutting oil and away you go. :wink:
By [URL=http://profile.imageshack.us/user/null]null[/URL] at 2012-09-14
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| Bret4207
09-14-2012 16:56:47
64.19.90.196
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| Personally, If all I had was a drill press that only went down to 200RPM, I'd go buy a 7/8" hole saw, put a 3/4" ho'made pilot on it and use some decent cutting fluid. I woudn't bother with a conventional drill bit at all. BT,DT got the tee shirt. At 200 RPM you'll burn that $30.00 drill bit up. You can buy 4 or 5 hole saws for $30.00.
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| LOU from Wi.
09-14-2012 22:13:47
174.124.40.181
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Bret4207, 09-14-2012 16:56:47
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| Bret4207, exactly right.We bought a complete holesaw kit wasn't a cheapy.Bored nice clean holes in one inch steel plate.Slow speed on floor model drill press used lubricant, mixture of break in engine prep & cutting oil. Worked for us. LOU
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| Ellis Kinney
09-14-2012 16:56:37
74.139.12.167
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| Zach, Don't worry about it, it is just a drill bit. I used to teach machine shop, so it's not the only one I've got. Let me know, Ellis
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| Ellis Kinney
09-14-2012 15:00:28
74.139.12.167
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| Zach; This is a simple operation if you have a drill press. Make sure you have the pieces to be drilled clamped well, or you might have a helecopter on your hands. Use an oil called tap magic. I have an assortment of drill bits, and I would be delighted to loan you what you need. You have my e mail address from previous communications. Ellis Kinney.
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| Zachary Hoyt
09-14-2012 15:53:54
184.12.64.194
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Ellis Kinney, 09-14-2012 15:00:28
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| Thanks for the kind offer. I am afraid of borrowing things like that since I might ruin them. I'll try whether I can get it done tomorrow, or if not I will buy a bit and try it out myself.
Zach
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| Brian G. NY
09-14-2012 15:00:02
72.10.203.95
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| I"d have that 15 bucks outta my pocket before you could say drill "chatter"!!
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| SDE
09-14-2012 14:57:05
174.124.27.214
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| If you try to do it yourself, attach a piece of metal over the top of the arm. A drill bit is a center cutting tool and it will want to walk unless you have a drill guide. Start with a bit that is about the same size as the point of the 7/8" drill. Drill that hole first and then use the 7/8" bit.Go slow with the speed and the feed rate. I personally like to use reamers to make existing holes bigger.
SDE
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| glennster
09-14-2012 14:25:40
75.57.143.173
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| farm and fleet has drill bits up to 1 inch, i bought a few there, they are about 30 dollars for a bit. drill slow and use oil or trans fluid to keep the bit cool. the bits are high carbon steel, nothing fancy but for a couple holes they will work fine. you can sharpen them too.
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| 36 coupe
09-16-2012 04:45:22
66.186.169.176
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Re: Boring a 3/4 hole to 7/8 in steel in reply to glennster, 09-14-2012 14:25:40
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| You can buy a 7/8 import drill bit for 7 bucks from WHOLESALE TOOL,They work fine for occasional use.Ive bought from them for 50 years.
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| glennster
09-14-2012 14:28:22
75.57.143.173
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Re: Boring a 3/4 hole to 7/8 in steel in reply to glennster, 09-14-2012 14:25:40
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| here is a link to your bit
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| Zachary Hoyt
09-14-2012 15:55:00
184.12.64.194
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Re: Boring a 3/4 hole to 7/8 in steel in reply to glennster, 09-14-2012 14:28:22
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| Thanks for the help. We don't have that company here but we do have TSC and Ace and such that probably have something quite similar.
Zach
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| johnpop1
09-14-2012 14:19:01
96.236.57.86
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| If you can actually find someone who will drill them for $15, I would probably have him do it. It would probably cost $50-75 to buy a decent drill for the job. If you plan on drilling more 7/8 holes, then it might make some sense to own your own drill. If you buy your own drill. buy the one with three flats on the shank. It will make the drill less likely to spin in the chuck. Also....if you decide to do it yourself, a heavy duty drill press would be in order.
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| Sean Feeney
09-14-2012 14:18:26
174.63.127.125
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Zachary Hoyt, 09-14-2012 14:12:21
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| Bit will cost you more than $15
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| 36 coupe
09-16-2012 04:52:54
66.186.169.176
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Sean Feeney, 09-14-2012 14:18:26
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| Another co I buy from sells a HS 7/8 drill for 7 bucks.
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| Sean Feeney
09-16-2012 17:04:45
174.63.127.125
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Re: Boring a 3/4 hole to 7/8 in steel in reply to 36 coupe, 09-16-2012 04:52:54
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| Do they have a web site, hows the shipping cost?
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| 36 coupe
09-16-2012 17:52:54
66.186.169.176
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Re: Boring a 3/4 hole to 7/8 in steel in reply to Sean Feeney, 09-16-2012 17:04:45
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| Kittstools. com.Shipping runs 10% or free over 600.00.
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| Sean Feeney
09-17-2012 07:46:35
174.63.127.125
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Re: Boring a 3/4 hole to 7/8 in steel in reply to 36 coupe, 09-16-2012 17:52:54
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