Drilling 1" Holes, in 1/4 inch steel

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Hey guys... Im drawing up a few plans for building a 3pt box blade attachment for a tractor... Ive made a few things, and i want to attempt a real project. Ive got everything planned out for it, except drilling the holes for the hitch pins. I only have a 2/3 hp drillpress, and a few odd bits (1/2" being the biggest) to work with, and i need to make 1 inch holes in 1/4 inch steel.Im thinking a hole saw, but im picturing something thats expensive to buy, and has a life expectancy of only a few holes. I dont know very much about this kind of thing. What would be the best way to drill these things, short of farming it out to a local shop or something?? I only have to make 3 per box blade...Any advice, guys?? Thanks in advance...[Account Abandoned 8/8/16 Please Do Not Attempt Contact Or Expect A Reply]. See you on YouTube! -ChuckE2009
Reply:Well,Either 1" bit or 1" holesaw, as you already know.Tim Beeker.
Reply:If it's just mild steel, a bi-metal hole saw should last through all that.  Not too expensive at all.Just go slow, use plenty of lubricant, and back out of the cut a lot, to remove chips.
Reply:get a one inch bit and start by drilling a smaller hole first then move up to the big bit350P 30A spool gun cut master 51  syncro 250 other stuff " take a dog off the street and make him prosper and he will not bite you sad the same cannot be said for man" i didnt use punctuation just to piss you off
Reply:I saw this on macgyver. use a torch and blow out your holes and weld in a sleeve of bushing .  Daye
Reply:Originally Posted by umahunterget a one inch bit and start by drilling a smaller hole first then move up to the big bit
Reply:I'd rent a Hougen drill and rotabroach those out in a few minutes. Everyone should use one of those at least once.
Reply:There's not much different between a bi-metal hole saw, and an annular cutter.The annular cutter will of course last a lot longer, and has grooves on its exterior for chip removal which allow for continuous cutting (with a hole saw you need to back out of the cut a lot to clear out chips).For just half a dozen holes in 1/4" mild steel, you'll spend more time filling out the rental agreement form than what a Hougen will save you by cutting faster.A twist drill is an option too, but your drill press may be on the low end of the power you need (and it may not go slow enough).  A 1" twist drill is around $20-25 bucks, and most have a 1/2" shank to fit into a normal drill press.DO NOT try to drill the hole it a lot of steps.  You will get an out of round hole.With a 2 fluted twist drill bit, you drill in two steps (two, and two only).The first, should be a pilot hole that is slightly smaller than the web of the final hole.  For a 1" final hole, the pilot will be around 5/16" or so IIRC.  The problem is that after that, you need a drill press with the power to finish the hole.  I've drilled some 3/4" holes with my 3/4" HP drill press (after drilling a pilot hole), and it was just about the limit of what the motor could do.  It would often slow down to the point that the centrifugal switch would kick on the starter windings (I've got enough hand control reflexes that it didn't bind, but that takes some experience).  I think 1" might be too much for it.Torching out the hole and welding in a bushing is probably what I would end up doing if the pin had any movement.  That way, you could use something better than mild steel around the pin.
Reply:I picked up this useful hole saw tip right here on Welding web…You need “Chip Relief”.   I would drill a couple of  3/8” holes on the inside tangent of the 1” hole.  This will allow the chips to escape from under the saw blade.   Use plenty of lubricant and a slow speed.
Reply:Originally Posted by BilldacatI picked up this useful hole saw tip right here on Welding web…You need “Chip Relief”.   I would drill a couple of  3/8” holes on the inside tangent of the 1” hole.  This will allow the chips to escape from under the saw blade.   Use plenty of lubricant and a slow speed.
Reply:Since its 1/4 use a hole saw (its cheap) go half way then flip the plate over and finish from the other side.  This keeps the slug from getting stuck in the hole saw and use oil.
Reply:You can avoid the holes altogether if you cut off the threaded portion of the hitch pin and weld it on. The flange on the pin provides a perfect surface. If it ever needs replacement (unlikely) it can easily be cut off and another welded in its place. Hitch pins are cheap.For the hole for the top link, most tractor places have Cat 1, 2, and 3 adapter bushings that are a couple of inches long. Depending on the size needed you can torch out the top link hole and weld in the bushing. It is hardened so would be better than just drilling a hole in the mild steel. The top link can take a beating on a box blade.Put a top link pin in through the two bushings to make sure they are aligned during the weld. The roughness of the torch cut should allow for good penetration around the bushing. After the bushings are in place they can be cut or ground down flush to the plate.
Reply:Originally Posted by BilldacatI picked up this useful hole saw tip right here on Welding web…You need “Chip Relief”.   I would drill a couple of  3/8” holes on the inside tangent of the 1” hole.  This will allow the chips to escape from under the saw blade.   Use plenty of lubricant and a slow speed.
Reply:Have a look at the Super Drill,  www.practool.com    Or buy a COLE DRILL  &  a 1" reduced shankbit.  Cole Drills are often  for sale on Ebay.
Reply:If the guy only has a mild drill press, he ain't going to have a welder/OA/mill.... 1" drill bits are not cheap, Hole saw gets my vote..........
Reply:Their not called hitch pins but are called lower link pins and I would do like GWD suggested and weld them on.Hitch pins is what you hook a wagon tongue with to the drawbar on the tractor.Last edited by dugndeep; 01-22-2011 at 11:13 PM.Maxus Pro-125 MigChicago Electric 90 amp DC flux-coreLincoln Electric AC 225 tombstoneO/A torchM/O mini-torch10 acres of flatland15 acres of holler
Reply:if ya got them UNIBITS are actually amazing up to 1/4 , easy on the hands and the drill and alot faster then waiting on a standard 1 inch drill bit , especially when it kicks back and ya gotta go resharpen it, i haven't had to purchase new ones in quite a while and seems like i use them on every job ! Just a thought though . JonI forgot how to change this.
Reply:Originally Posted by dugndeepTheir not called hitch pins but are called lower link pins and I would do like GWD suggested and weld them on.Hitch pins is what you hook a wagon tongue with to the drawbar on the tractor.
Reply:I didn't mean to sound like a smart***,I was just trying to figure out why we was drilling 1" holes for hitch pins.I'm a little slow until I read futher and knew he meant lower link pins or lift pins.Maxus Pro-125 MigChicago Electric 90 amp DC flux-coreLincoln Electric AC 225 tombstoneO/A torchM/O mini-torch10 acres of flatland15 acres of holler
Reply:Originally Posted by BoostinjdmLike this......A hole saw would be my first choice of the tools I have.
Reply:Originally Posted by farmallI'd rent a Hougen drill and rotabroach those out in a few minutes. Everyone should use one of those at least once.
Reply:If you are still in the planning stage, you may want to forgo a lift pin on a box blade and go with a clevis-type mount. Box blades put tremendous stress on the mounts and 1/4" steel will easily bend. With a clevis mount the force would be straight rather than twisted. The holes will also elongate unless bushed in a clevis-type set up.See these photos of a Cat 1 clevis-type hitch. It is made from much heavier plate than you are considering using. (Never mind the orange spacer and Cat 2 -> Cat 1 bushing on the pin.)Anyway, you can weld Cat 2 -> Cat 1 hardened bushings in the torch or plasma cut holes to make a nice mount. A way to do it was described in an earlier post (#12) about using bushings in the top link mount. The same method would work with the lower arm mounts. Use the pin to line up the bushings for welding in place.The bushings should be less than a dollar each. Attached Images
Reply:Originally Posted by BoostinjdmLike this......A hole saw would be my first choice of the tools I have.
Reply:just my 2 cents here, when i use a hole saw on the drill press for steel cutting I use the lowest speed on the machine & blow the chips out of the cut path using a blow gun attached to shop air & no lubricant. I learned this from older welder while i was watching him work in his shop. it has worked fine for me & i have cut up to 21/2"holes with great results. I find lennox holesaws to be the best.                                                                                                  Bob
Reply:Lanse, you said 1" holes for the hitch pins. The lift pins on a cat 1 are 7/8" dia. and the top link is 3/4", a cat 2 lift pin is 1-1/8" dia. I just wanted to make sure you drill the right size hole. I have made lots of attachments for cat 1 and you can use a uni bit http://www.irwin.com/tools/brands/unibit these work very good for the larger holes, you may have to drill from each side because these bits only have a 1/8" to 3/16" shoulder, but they will give you a nice bevel on the holes. I have used these on thicker stock cutting in from each side and finished the center with a die grinder and bit.I built implements for years without fancy tooling.Mark the hole with a punch, use a compass and a silver pencil to mark the hole(silver shows up best when using the torch), then cut it with a torch.The hole may be a little off.  So What.Use a cone shaped stone on your grinder to finish the hole to proper diameter.Cone stones are, or should be, available at your LWS.  (see the Flexovit catalog)And, if you don't have a grinder, or don't want to spend the money on fancy stones.....just feather the hole slowly with the torch.  Use the pin you plan to insert, and test fit it as you blow metal out of the hole.  A little slop doesn't matter.  It will wallow out with time anyhowA few thousands off won't hurt.  The arms on your tractor have enough slop to compensate for the slightly off pins and holes for the upper link.I don't mean to seem like a b###breaker, but precision is good in some instances, but not necessary in this instance.  If you're within a 1/4 inch, you're good in most cases."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Buy a 15/16 or 1" Silver & Deming drill bit with a 1/2 drill shank  or get a annular cutter and adapter with MT or straight shank for your drill press and drill away.  John
Reply:I hate to sound like a dumb...,but what does silver & deming mean?I had somebody else ask me the same question and had to tell them I didn't know(lol) Does it just mean 1" or above sized drill bits with a smaller shanks.Last edited by dugndeep; 02-25-2011 at 10:56 AM.Maxus Pro-125 MigChicago Electric 90 amp DC flux-coreLincoln Electric AC 225 tombstoneO/A torchM/O mini-torch10 acres of flatland15 acres of holler
Reply:Apparently Silver and Deming manufacturing company were the first to make a bigger diameter smaller shank drill bit but didn't patent the idea but the name stuck,large bore drill bit with a smaller diameter shank,now I knowMaxus Pro-125 MigChicago Electric 90 amp DC flux-coreLincoln Electric AC 225 tombstoneO/A torchM/O mini-torch10 acres of flatland15 acres of holler
Reply:Here's a whole set for only 30 bucks, not the highest of quality but if you use them at the proper speeds, should last quite a while.  http://www.harborfreight.com/8-piece...t-set-527.html
Reply:I vote for uni-bits. They are great! I get the sets from HF and they last quite a while. I have bought other brands that were just as good, but for the money HF uni-bits are great! Catch them on sale and they are usually 50% off. If you break one, oh well, they weren't much money at all.
Reply:Originally Posted by farmallI'd rent a Hougen drill and rotabroach those out in a few minutes. Everyone should use one of those at least once.
Reply:I use a plasma cutter to make holes in metal if I have to drill several holes.  I drill a hole in 1/4 inch scrap aluminum to a size that allows my plasma cutter to use to get the final hole size and use it as a pattern. Cuts down on wear on my hole saws.I then drill a small hole in the material I need to drill to allow for a good start to the cut. Any hole larger than say 3/4 inch I do this and it is the fastest way to put a hole in metal without having to drill through the steel several times. Now for flat plate or sheet, I just put it on the CNC table and away I go.....fastest way to make a hole without drilling for sure!
Reply:Needing to make somewhat larger (3" to 4" diameter) holes in  somewhat thicker (1" to 1-1/2") steel (mainly A36, but sometimes T1 or A400) than the OP mentioned, I decided to contact all the usual suspects prior to purchasing any new equipment.This list included Lenox and Starrett for bi-metallic hole saws, plus Hougen and Jancy for HSS annular cutters.All four firms confirmed that their products/technology was up to the task if:1)I had a rigid & powerful enough drill press (insufficient rigidity [not power] was mentioned by all four firms as the prime cause of ‘poor performance’)2)I had a flood (not a misting) coolant system (ideally using a water miscible synthetic cutting fluid at an 8:1 [water/fluid] ratio that was produced by a reputable lubricant company [Mobil/Texaco/Gulf/etc.])Regarding hole-saws, both Lenox and Starrett further stipulated:3)Drilling needed to be done in a ‘pecking fashion’ (ie: frequently raising the hole saw to blow out the chips)4)Bi-metallic hole-saws were suitable and carbide tipped hole-saws weren’t necessary (but could be used)However when I inquired about drilling ‘chip relief’ holes to help clear chips from under a hole saw (as has been suggested by other thread contributors here, and is frequently put forward as a method in other forums as well), I was told in no uncertain terms that this was absolutely the worst thing I could do regarding proper hole saw usage. Both Starrett and Lenox maintain that the teeth of a hole saw need to have uninterrupted contact around the complete hole periphery to maximize their lifespans, and that chips need to be cleared from hole-saws much more frequently than is done by the majority of users. Both contend that 'chip relief' holes do not work as their proponents suggest.Regarding annular cutters both Hougen & Jancy said:5)I  needed to drill at about 150 rpm for A36 steel, and no more than 80 rpm for T1/A400 steel6)That cutters of this size should only be used manually (ie. no power feeding)Given that Lenox's and Starrett's position regarding 'chip relief' holes directly contradicts what many forum members have suggested doing, I just thought that I would pass on the operating recommendations that I have been given for the forum members perusal.
Reply:I have cut 3 in holes in 1" plate before with a hole saw in my drill pressnot sure of the grade. Like you stated bloww chips out frequenlty and use a lot of oil. My drill press is a old old old beast with a 2 hp motor and uses 3" wide flat belts for the drive. Weld shop I bought it from drilled 1 1/2" holes with a twist bit with it. I drill alot of 1" holes with it. II dont drill chip relief holes seem to cause the saw to grab.Millermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:I agree with the Unibit or equivalent.  This is what I use - just happens to be 1" and 1/4" material.Key is to not run them fast and apply moderate to heavy pressure to keep them cutting.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:I'd rent the Hougen drill. They are sweet, sweet tools.
Reply:Originally Posted by yank132Both Starrett and Lenox maintain that the teeth of a hole saw need to have uninterrupted contact around the complete hole periphery to maximize their lifespans. . . Given that Lenox's and Starrett's position regarding 'chip relief' holes directly contradicts what many forum members have suggested doing, I just thought that I would pass on the operating recommendations that I have been given for the forum members perusal.
Reply:Grr.. Mag drills don't stick to 1/4" very well. Almost got flattened by one that popped. Whatever I can't tackle with a nice sharp S&D and either of my magnums, corded or cordless, I take to my Caser radial arm drill. It's big, old, and ugly, but it will push a 4" drill through whatever I want. And it makes such beautiful chips in the process...mens agitat molem
Reply:rlitman,There are a myriad of forum contributors on a plethora of forums who champion the use of 'chip relief' holes. All these proponents seem to believe that this methodology has merit.Never having personally used a 'chip relief' hole, but well understanding the theory/idea behind it, I wanted to get at least a few hole-saw manufacturers 'take' on 'chip relief' holes before I bought either some bigger hole-saws, or stepped up to annular cutters.All I was doing was passing on what both Lenox and Starrett told me. They both went in to all sorts of detail about hole-saw usage and the downsides to this technology. Both seemed to be quite knowledgeable about the 'chip relief' school of thought, but neither had a single good word to say about this approach.If there was a shred of benefit to the use of 'chip relief' holes, why are both Lenox and Starrett so dismissive about them? Surely they know how to maximize the lifespan of their products? Or don't they?Neither questioned the use of hole-saws for making the size and depth holes I mentioned in my post above. But they both harped on and on about drill rigidity and flood coolant. I'm just the messenger. Now: could both Lenox and Starrett be keeping various facts to themselves in the hope that more hole-saws will be ruined by users and hence they will have higher sales? Stranger things have probably happened.Will I be trying 'chip relief' holes? Don't even know if I'm going to trying using hole-saws to make the holes in question yet. But what I've been told by Lenox and Starrett certainly is not a vote of confidence in the 'chip relief' method.ncfh,Your mention of a Caser RAD brings up a question? How big is the one you have?When I asked about the correct sized machine to make the size holes I mentioned above on another forum, the consensus of opinion was that I really needed at least an 5MT spindle, at least a 5 HP motor, and a drill that weighed over 6500 lbs.Some even felt that a 6MT beast perhaps pushing 9000 lbs was required!Maybe if I was trying to push a 4" twist drill through a 3" piece of A400 without drilling a clearance hole I could see needing 15 + HP and a 6MT spindle.But using an annular cutter? I would think that any reasonably well made 2HP 3MT drill press that could run at 150 rpm would be up to the task of making 3" holes in A36 with an annular cutter at least once in awhile. Perhaps not every 15 minutes all day long, but once or twice a week shouldn't kill such a drill press.I've seen a 3MT 2800 lb (+/-) Caser RAD for sale. You say yours will push a 4" drill through anything you can put under it. So; what are the specs for your Caser RAD?
Reply:Resharpening a 1 " Twist Drill to be roughly like what in Wood Working is called a Brad Point Drill, allows the use of a small Pilot Hole to ease the center doldrum condition, and, this form of Drill then, in drilling Steel, if sharpened correctly, will cut wonderfully and with less Horsepower needed, and, it will not 'grab' as it comes through the back.Most Twist Drilles have a geometry to the end which anticipates high production rates of feed, and, if having a low Horse Power Drill Press, this is best re-done to anticipate a lesser rate of feed anyway for any of the larger diameter Bits...and the Dril Bit then becomes more forgiving also, far as grabbing in gummy Metals or if one is pressing a little too hard.With a reduced Shank type, this can allow a lower Horse Power Drill Press to still manage alright Boring Holes quite a ways beyond it's rating, as long as you do not really push it with the feed rate.This form of Twist Drill Bit also allows one to Drill through thinner Sheet Metals with no grab issues going in or when coming through, since the Drill Bit is cutting from it's periphery first, and in from there...so when it comes through the back of the material, there is a 'disc' of the Hole Diameter less a tad, which usually clings to the end of the Drill, and one knocks that off with a small Stick ot whatever.I have sharpened old larger Twist Drills to this form and been very happy with their performance.Good Lube and plenty of it of course, is always best for the Drill not to get hot in use and spoil the wonderful Sharpening job one just spent time and trouble to acheive.Last edited by Oyeboten; 06-08-2011 at 06:13 AM.
Reply:Here's how I drill holes in 1/4" steel. I can make holes that are very tight tolerance on my plasma cnc machine.....down to as small as 1/4" diameter. There is a very slight taper in the holes....and a small visible notch where the arc enters the cut path. A 1" hole in 1/4" steel takes about 4.5 seconds to cut.....I realize that not everyone has a plasma/cnc, but there seems to be an impression that plasma holes all need rework to be acceptable. Most of the holes cut on my machine require no rework! On the larger part below....I even cut the holes for tapping 1/4"-20....they were cut with the plasma to .188", then a .201" cobalt drill bit was used to true them up and remove the hardened edge....then were conventionally tapped.1st 2 pics....showing as cut holes on 1/4" steel. Smallest hole is 3/16", largest is 1".3rd pic...large bracket with all contours and holes plasma cut. small holes were then drilled (cobalt drill only!) and tapped 1/4"-20.Jim Colt Attached ImagesLast edited by jimcolt; 06-08-2011 at 08:04 AM.
Reply:SHOW OFF!! How goes it Jim?MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:SHOW OFF!! I'll second that   LOLMaxus Pro-125 MigChicago Electric 90 amp DC flux-coreLincoln Electric AC 225 tombstoneO/A torchM/O mini-torch10 acres of flatland15 acres of holler
Reply:I had to put that in this thread! Still....it is difficult to pick up my cutting machine and use it like a mag-drill!Jim
Reply:I'll put another vote in for the UNI bit or step drill. As a matter of fact just the other week I drilled 1.25" holes in some 1/4" material with my HF special table top drill press (1/2hp). The bits i got from HF, there were two in a kit for about $10 and they have cut quite a few holes already.Looks like they are on special now: http://www.harborfreight.com/
Reply:I have 4 of them,2 are irwin uni-bits and the other 2 are Craftsman.They will surprise you on how well they drill a hole and their longevity. Attached ImagesMaxus Pro-125 MigChicago Electric 90 amp DC flux-coreLincoln Electric AC 225 tombstoneO/A torchM/O mini-torch10 acres of flatland15 acres of holler
Reply:Originally Posted by HarleyscooterLanse, you said 1" holes for the hitch pins. The lift pins on a cat 1 are 7/8" dia. and the top link is 3/4", a cat 2 lift pin is 1-1/8" dia. I just wanted to make sure you drill the right size hole. I have made lots of attachments for cat 1 and you can use a uni bit http://www.irwin.com/tools/brands/unibit these work very good for the larger holes, you may have to drill from each side because these bits only have a 1/8" to 3/16" shoulder, but they will give you a nice bevel on the holes. I have used these on thicker stock cutting in from each side and finished the center with a die grinder and bit.
Reply:Originally Posted by rlitmanIf it's just mild steel, a bi-metal hole saw should last through all that.  Not too expensive at all.Just go slow, use plenty of lubricant, and back out of the cut a lot, to remove chips.
Reply:I like the step bits, but I'll tell you what - putting holes in spring or hardened steel with anything mechanical sucks.  That is one place where OA cutting torch shines (in skilled hands).  I punched a bunch of 5/16 holes recently with it and was reminded of how much I like having an OA setup in the shop.Hobart LX235Victor 250 Oxy-Acetylene Rig (welding and cutting)Bobcat 773F-350, 1999, 4x4, 16' 10K# trailerOutdoor Wood Burner - 10 cords/year