Draw-bar hole enlarging?

[georgerkahn]

I hope you can provide me some direction. I have a draw-bar for my tractor's 2" receiver hitch on rear, and it has a 3/4" hole in it, for a ball with 3/4" shank. My challenge is newest to me trailer has a 2 5/16" coupler, so I need to screw on a ball of that size. BUT, all of these size balls come with a one inch shank.

Here's my question: Not knowing the properties of the steel draw-bar is made of, I was thinking on fastening it to vice on my (old Delta) drill press. Put a 3/4" drill in chuck to make sure it is 100% in line. Then replace 3/4" drill with a 1" one, and slowly -- with safety glasses on and a bottle of thread-cutting oil in hand to keep steel wet -- attempt to increase size of hole to one inch.

I have S&D drill from 1/2" up to about 1 1/2" in 1/8" increments -- should I go in smaller steps than directly from the 3/4" to 1"? And, is the steel they use for draw-bars too hard for my attempt using a drill bit?

I have too many tools in my shop to readily count, but I have gotten hurt/wounded from the drill press MORE than any other tool(s)!!! (I was a slow-learner on importance of using vice/clamps) Not wishing an accident -- is another reason I'm posting this.

Am I on the right track? One of the major issues is that to clear backhoe, the receiver hitch is quite short - so if I purchased a new draw-bar with a 1" hole, I'd have to both hacksaw off a few inches from rear as well as drill a new hole for retaining pin.

I'm hoping you may offer direction?

Thanks much in advance!!!
geo

[smokeywolf]

If I were in your shoes, I think I'd find a scrap piece of at least 3/8" thick steel. Put a 3/16" pilot hole in it, then follow with your 1" inch drill. Clamp that scrap with the 1" hole over the hole in your draw-bar to act as a drill bushing for the 1" drill. Go slow and use lots of cutting oil.

NEVER try to hold something in your hands while drilling it. ALWAYS clamp it down.

[Jim K.]

The easy fix would go to NAPA and get a 2 5/16 ball with a 3/4 shank....That is what I did, would take a hardened bit to drill a drawbar.

[JonB_in_Glencoe]

you don't say what the trailer is, but I'd consider replacing the coupler with one for a 2" ball, it the coupler isn't welded on...unless there is a reason why this trailer needs the 2-5/16 coupler?

[country gent]

The big issue will be from 3/4" to 1" is only 1/4" or 1/8" on a side. unless you resharpen the drill with less relief ( more like one sharpened for brass) it is going to want to grab and thread itself into the stock. The rule of thumb is a pilot hole the dia of the web on the drill. a 1" drill is probably around1/4"-3/8". Depending on your drill press a solid stop for the vise to bear against or solidly clamped down is important. Heavy Strap clamps would be better than c-clamps. The Steel is tough and cuts hard but can be cut Run slow with lots of oil and keep it cutting don't let it rub as this may work harden the piece.

[Plate plinker]

I like making things too, but buying a different ball is a lot easier. Or just make a new drawbar and weld a ball on it.

[bearcove]

Clamp it, drill it, use oil. Its just steel.

[bob208]

it is going to take a better drill press then one of the common ones bought at tractor supply. you can not get them to turn slow enough. plus they are not ridged enough to use that big of a bit. tractor draw bars are not hard a little tough maybe but nothing better then 4140.

now if it were me I would set the part up in the mill and open the hole up with a boring bar.

[georgerkahn]

THANKS MUCH to all who have kindly responded!!! The trailer is a Carry-on Brand for hauling the tractor, and coupler is welded on, with a dedicated battery box (for brakes) on a bracket at aft end of it. I had thought re changing coupler, but pretty much ruled that idea out. Any replacement would necessitate both cutting and rewelding. :(
I think I best like the idea/suggestion of drilling first through scrap steel, and following with a 1" bit. My drill press is a fairly stout Rockwell Delta floor model from the early 1960's, sporting a magnetic switch to control its 1 hp motor, foot pedal feed, and a 14-speed pulley doo-hickey (technical term) on top, which will allow me to really slow it down. Upon my purchase, I upgraded the chuck, too, to a good commercial version which should minimize bit spinning -- most likely, if it grabs, motor will be stalled.
I repressed the notion of the bit grabbing and trying to screw itself in -- which is perhaps (fear?) why I posted this query in the first place.
So, Plan A will be for me to change belts on pulleys to really get the slowest speed, attempting to drill with it well-lubed and clamped well.
If I'm lucky/successful, great. If not, Plan B will be to put a new blade on a hacksaw, and try cutting the tube down in length.
Again, my sincere appreciation -- I reckoned if any seasoned machinists were anywhere -- it'd be :) this site! I'm hoping that bob208's suggestion that the bar is simply, "a little tough" will prove to be true. Sadly, one of the "facts" of getting older is two really good machinist friends with a shop full of milling machines and lathes have both predeceased me... My lathe is but a tiny Unimat.
geo

[bob208]

in most shops we cut three flats on the drill shanks that way they can not spin. your unimat lathe mite be able to do the job look up boring between centers. if you run into a hard draw bar it will be the first one i have heard of and I have drilled a lot of draw bars and mounts for trailers.

[smokeywolf]

One of the things I used to do to minimize a drill from grabbing on break-through and screwing itself down to the chuck, was to drill half way through, then flip the part over and finish the hole by drilling from the opposite side.

[runfiverun]

the bigger shanks and balls are for weight rating.
they make 2 different diameter shanks for the 2" balls for a reason, they are pretty much the break-over point.

[RU shooter]

Unless you already have those big bits I'd call around and find a shop that has a water jet . It would take all of about 2 min to cut that hole and they would prob do it for about the same price as it would cost to buy a good 1" bit .

[Strtspdlx]

No carbide burrs? I have done it before. It is somewhat time consuming if you don't have good bits.

[Blanket]

If what you are calling a drawbar is a hitch adapter that you slide into a receiver and put a 5/8 pin thru, buy one with a 1" hole and cut down to fit and redrill the 5/8pin hole. If it is the drawbar of a tractor run your drill as slow as possible and clamp the drawbar to the table. It will not grab until you are about to break through the bottom side. With a 1hp drill with a foot pedal you should be fine. Just reduce the feed pressure as you get close to breaking thru. Most draw bars on tractors are made out of a CM steel and are tough, not hard

[jonas302]

No problem at all means you have your drill press and bits no reason to buy anything else I have had to drill holes like that many many times with a cordless drill not as fun as my big mag drill but when repairing stuff you do what you need to do if I drill wasn't close by or didn't I would cut it with a torch

I got curious went downstairs and poked a drill in a hitch to check hardness... Soft as a babys bottom Be safe and you will have no problems

[lightman]

If you have a set of bits that big and a drill press I would not hesitate to flood it with oil and drill it out. Clamp it down and crowd it just enough to make the bit cut. I would probably just use one bit, I don't see the need to drill in steps.

[leadman]

Run the belts on your drill press a little loose so they will slip if the bit sticks. I've done things like this many times and you should not have any problems if you secure the bar so it can't spin around. I would try to have it up against the drill press post.

[elk hunter]

If it were me I'd put it in the drill press line it up and clamp it down and using the slowest possible speed try to open the hole with a regular high speed steel drill bit. If it proves to be too hard I'd go buy a 1" carbide masonry drill bit and use it. Masonry carbide bits will drill through some mighty hard steel if you keep the speed and the chatter down. With carbide you need flood coolant or none at all as you can shock cool carbide and cause it to crack.

[bedbugbilly]

I'd try to find a ball with the 3/4" bolt first but if you have to enlarge the hole in the bar, that might be a tad bit much for your drill press. Do you know anybody with a vertical mill that could clamp the bar and use a 1" mill to go down through the hole?

[10x]

My grandfather was a master blacksmith trained in Norway prior to 1898. His solution would be to heat the draw bar to just warmer than cherry red, use a taper punch that went parallel at 1" to enlarge the hole, then retemper the draw bar.

[georgerkahn]

Well, the weekend is upon us -- so tomorrow (Saturday) I'll put on some heavy gloves, goggles, and give it a try. I like the loose belt idea -- never heard of it, but will try it, as it sure beats getting hurt (again). Will clamp it for all it's worth with a 3/4" bit used to line it up precisely; then, replace that with a newly sharpened 1" bit. I'll be most generous with the cutting oil, and use minimal pressure. I have a 3-spoke wheel for chuck, so I intend to have almost as much pressure going up, as the teeny tad more going down, to hopefully remove some steel... If I'm successful, I'll drill about 2/3rds through, and then using another poster's suggestion, flip it.
Oh -- before I start, I'll ping it with an automatic centre-punch to determine how hard it is. IF the punch doesn't even mark it -- then I'll need find someone with machinery to do it for me. [NOTE: this is for my tractor, pulling trailers (1 7/8", 2", and 2 5/16" balls), as well as chippers, winches, etc. in woods. Hence, I'm not too concerned with needing 7,000 pound sheer for the big trailer. Hey -- it'll be pulled by the tractor I bought the trailer to be transported on. IF I used a "standard" NAPA type Reese drawbar, it sticks out too much, in way of bucket on front, and/or backhoe on rear. YES, I'd go the easy route and just buy one that would work -- if it would. THANKS for suggestions!!!!]
geo

[Blanket]

If you cannot drill it out, send it to me and I will put a 1" hole thru it. PM me if needed.

[Teddy (punchie)]

Clamp it, drill it, use oil. Its just steel.


Yes this is what I would do, don't press too hard or have drill spinning too fast .

[Blanket]

Yes this is what I would do, don't press too hard or have drill spinning too fast . This again

[bob208]

try a file if the file will cut it then you can drill it. it the file just slides on it you will not get a hole in it.

[Boolit_Head]

Something is knocking the dust off a brain cell and making me think you are talking the difference between a Class 2 (3/4 inch hole) and Class 3 (1 inch hole) hitch. For the price go get the stronger hitch, that is what I did. I could tell the difference, the class 3 hitch was a solid bar and stronger and thicker.

[too many things]

bar is not harden drill will work fine , just go slow as 1in has a lot of grab

[skeettx]

Good luck, go slow, use lots of cutting oil
Mike

[Blanket]

fer crips sake it is for a tractor, not pulling a trailer down the road at 70 mph. It does not need a waterjet, hammer of Thor blacksmith treatment, or other nonsense. It needs a 3/4 inch hole drilled to 1 inch. Face palm

[10x]

fer crips sake it is for a tractor, not pulling a trailer down the road at 70 mph. It does not need a waterjet, hammer of Thor blacksmith treatment, or other nonsense. It needs a 3/4 inch hole drilled to 1 inch. Face palm

My grand fathers name wasn't Thor. That was my great grandpa.

Sometimes folks don't have access to some tools.
And drilling a 3/4 " hole out to 1" can be a challenge if one does not have the bit and a drill that can handled it
I would buy a ball that took a 3/4" bolt

[georgerkahn]

Still another true brilliance! Thirteen degrees out there, now, so I may wait til noon to go out and attempt my enlargement -- 'tis supposed to reach "mid-high 20s today"; 25* I can handle ;). This site -- 'specially folks on it -- is/are awesome! To wit, I'd never had thought of bob208's suggestion vis trying a file. You'll never guess what the very first thing I'll be doing when I go out to shop? If the file cuts, I'll have Guiness-book confidence in drilling it! And, if not, I may be contacting Blanket... Yes, this is an annoyingly "simple" challenge, and I'd much rather be able to buy a ready-made unit -- but, I tried explaining in earlier post the total size limitations of my Kubota -- and, I do need receiver hitch on tractor for Lewis winch. Too cold to do much outside -- including :( casting -- so this seems an apt project so I have it to use in that narrow time window from last-snow through black fly season. (Depending, some years 2 months; others, 2 days!)
Thanks again to all!
geo

[pmer]

If you have a set of torches you could even cut the hole a little bigger too. It wouldn't be as pretty as drilling but would work just fine especially if you have something a little bigger than 1'' to put over the hole to use as a guide for the torch.

[Teddy (punchie)]

Yes this again. How big of tractor ?? Just a drawn steel not case hardened. Not a cast hardened. Easy to weld and re-drill ask how I know. I have fit and worked on a number of hitches over the last years like 35 years . So yes this again. Only trouble you should have if you have a bit that is dull. Or you run a large bit too fast. Or maybe it was sharpened at wrong angle. They are a high grade steel but not harder then average tool steel. If it were me as done in past drill it out right on tractor. but if you need to repair one disconnect the battery (s) so not to fry your electrical system.

SO Blanket yes this again !!

if have even used a file to get the pins in if it was close, sometime the wear funny after 50 years of use. have to repair one on a 70 + HP tractor this year as bar is getting some wear where it rides the hitch carrier.

An other way to check hardness is to see if bit will sore the metal, all ready talked about a file, a screw drive, even a hammer can tell you about how hard, spark size coming off grinder. Sometime if you hit it harder better steel has a ring to it.

Just a dump farmer here what do I know.

Just go slow and drill it. Use oil to keep cool or even water oil mix, sometimes the whipped mix hold on bit and metal better.

only thing I'm not sure of is the turns per minute on the larger bits. I recall being yelled at in evening shop class for dulling an 1 1/4 for drilling too fast through a welded piece with an 1 1/2 on a mill. What I recall was no fast then 40-60 TPM (turns per min.) and to clean off as much of the slag from weld as you can. Do as much prep before you drill as you can to clean up the area to be drilled, bit was new and cost was over 100 bucks and shop teacher was just a little unhappy with Theo .

[Blanket]

Still another true brilliance! Thirteen degrees out there, now, so I may wait til noon to go out and attempt my enlargement -- 'tis supposed to reach "mid-high 20s today"; 25* I can handle ;). This site -- 'specially folks on it -- is/are awesome! To wit, I'd never had thought of bob208's suggestion vis trying a file. You'll never guess what the very first thing I'll be doing when I go out to shop? If the file cuts, I'll have Guiness-book confidence in drilling it! And, if not, I may be contacting Blanket... Yes, this is an annoyingly "simple" challenge, and I'd much rather be able to buy a ready-made unit -- but, I tried explaining in earlier post the total size limitations of my Kubota -- and, I do need receiver hitch on tractor for Lewis winch. Too cold to do much outside -- including :( casting -- so this seems an apt project so I have it to use in that narrow time window from last-snow through black fly season. (Depending, some years 2 months; others, 2 days!)
Thanks again to all!
geo
Did you get her done? Let us know.