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Hello all, I was making a few 4"x4" wall brackets from 10ga wild steel and needed to drill 8 mounting holes for #10 screws. 7 of the 8 hole were no problem but while drilling the 5th hole the titanium coated bit just spun in place making a small dent. I used plenty of drilling oil. I tried two times and on the third attempt the drill bit glowed bright red. I switched bits, more oil, and still no luck. Finally I flipped the piece over and successfully drilled it from the other side.Did I do something wrong? Cheap mild steel had a hard spot? I probably hardened the spot with the heat. Is this common?Old Lincoln Weld-Pak 100 MIG conversion Vulcan 220 Omnipro
Reply:The flat bar may not be A36.Are you using scrap ?Dave
Originally Posted by Flyer58
Hello all, I was making a few 4"x4" wall brackets from 10ga wild steel and needed to drill 8 mounting holes for #10 screws. 7 of the 8 hole were no problem but while drilling the 5th hole the titanium coated bit just spun in place making a small dent. I used plenty of drilling oil. I tried two times and on the third attempt the drill bit glowed bright red. I switched bits, more oil, and still no luck. Finally I flipped the piece over and successfully drilled it from the other side.Did I do something wrong? Cheap mild steel had a hard spot? I probably hardened the spot with the heat. Is this common?
Reply:Not uncommon. If dead set on entering that spot, I have had success spot annealing plate. Casting can be a real pain, I have had multiple boxes, where 50 from one lot drill fine, then none from another lot will drill.
Reply:
Originally Posted by smithdoor
The flat bar may not be A36.Are you using scrap ?Dave
Reply:Sounds like you work hardened that section with that bit not actually cutting. Sounds like the bit needed a re-sharpen. Before most every drill operation I do, I re-sharpen my drill bits. Get a drill sharpen gauge. I just use a protractor and set it at 55 degrees or so. You know the drill is cutting nicely when it cuts from both sides. If it is not, stop and re-sharpen using a tool.www.tjsperformance.comDynasty 300 DXHTP 240HTP Microcut 380Hyperthem 85JD2 Hyd Bender and HF Hyd Ring Roller all in one =(Frankenbender)Bpt. Mill/DRO4' x 8' CNC Plasma TableInstagram: tjsperformanceYT: TJS Welding and Fabrication
Reply:
Originally Posted by TJS
Sounds like you work hardened that section with that bit not actually cutting. Sounds like the bit needed a re-sharpen. Before most every drill operation I do, I re-sharpen my drill bits. Get a drill sharpen gauge. I just use a protractor and set it at 55 degrees or so. You know the drill is cutting nicely when it cuts from both sides. If it is not, stop and re-sharpen using a tool.
Reply:What size bit? Speed? Hand drilling or drill press?
Reply:New should be A36.Then I look at the drill bit . Dave
Originally Posted by Flyer58
Not scrap, I bought it at the local mill supply store. I never asked about the rating.
Reply:Skip those cheesy Chinesium-covered drills and buy better ones. Cheap tools, cheap results.Titanium coated? Yeah, sure thing. Or, buy a huge box of them from Crappy Tire and throw them away after each hole.Do not believe everything that you think.
Reply:Coated shmoted. Don't let the advertising get you. Sharpen them as normal.www.tjsperformance.comDynasty 300 DXHTP 240HTP Microcut 380Hyperthem 85JD2 Hyd Bender and HF Hyd Ring Roller all in one =(Frankenbender)Bpt. Mill/DRO4' x 8' CNC Plasma TableInstagram: tjsperformanceYT: TJS Welding and Fabrication
Reply:I use a bench grinder, fine wheel. There are people on Youtube demonstrating the technique. I do it by eye only. I usually touch up any bit I intend to drill anything hard with.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:
Originally Posted by Willie B
I use a bench grinder, fine wheel. There are people on Youtube demonstrating the technique. I do it by eye only. I usually touch up any bit I intend to drill anything hard with.
Reply:
Originally Posted by Oldiron2
Also, mild steel shouldn't be able to work harden. Could your bit have chipped badly when breaking through a previous hole, so was just rubbing, not cutting?
Reply:Correct mild steel should not be able to work harden but his bit glowed bright red on the steel. Hence now it is brittle and will drill like glass. This is like trying to redrill a hole that was cut by CNC plasma. Been there.www.tjsperformance.comDynasty 300 DXHTP 240HTP Microcut 380Hyperthem 85JD2 Hyd Bender and HF Hyd Ring Roller all in one =(Frankenbender)Bpt. Mill/DRO4' x 8' CNC Plasma TableInstagram: tjsperformanceYT: TJS Welding and Fabrication
Reply:Switch to self drilling screws. Then you just go through 20 screws on hard steel. Many years ago, The best change I made for drill bit longevity is controlled drill speed on larger bit and constant vertical pressure.
Reply:Hand sharpening bits under 1/4" is very hard to see if you have the right angle, relieve and the point centered. It's possible the steel the OP was drilling just had a hard spot right where he was drilling.
Reply:
Originally Posted by tapwelder
What size bit? Speed? Hand drilling or drill press?
Reply:
Originally Posted by Oldiron2
Willie, what's the smallest you can sharpen accurately? Over the years I've acquired (meaning found) a number of 'sharpening" tools (and some piles of dull bits too) and find problems with most of them, but have gotten most to work decently on larger bits. Anything under about 1/8" is difficult to do, to get both sides of a two-flute perfectly the same. Being somewhat creaky, I never got the hand method down as well as I'd like except for on large bits.To the OP; I second the other comments about the T. coating, if the bit wasn't sold be a genuine good company (e.g. Cleveland Twist Drill). Where did yours come from? Also, mild steel shouldn't be able to work harden. Could your bit have chipped badly when breaking through a previous hole, so was just rubbing, not cutting?
Reply:I am a hand driller. I collect a few bits and some are a consumable and shat happens. They get brittle so to speak from stress and flex too but I actually get them from a flea vendor goes to huge trade exhibition show, been there yearly for decades and worth a visit. Saw a guy come just to buy a complete set but the grab bags are really good for general fab and love the 1 over sizes and 1 under for taps too but had some of them by the pound even and I look at my collection and I bought 10 pack of 17/64 and blow some paint in the baggie so I can recognize and buy 10 a time for some pilots. 1/8 is obviously used but I like 9/64 better, just a little stronger, some 3/16 too I buy some every hear, I sharpen a few, I dont take care of them but big difference when I get 25/50 holes from a bit I paid 1 dollar for is a deal. I drill dry, can of juice lasts me a long time, really brutal and punch and horse holes with a heavy duty battery drill.www.urkafarms.com
Reply:
Originally Posted by Flyer58
3/16 bit on a drill press at 2030 rpm. and yes a cheap chinesium coated bit which cut other hole with little effort. Glowing bright red I half expected it to friction weld itself to the piece I was drilling.
Reply:
Originally Posted by wb4rt
Way too fast rpm in my opinion. I drill on lowest rpm on my drill press, which sometimes is too fast.
Reply:I have a package of drill bits my father purchased in 1960's. Great looking But try drill soft steel they will glow red . They where low cost wood drill bits.Dave
Originally Posted by whtbaron
My thought as well... I've got my drill press down to 80 rpm and I like it there. I've also seen the titanium coated bits fail to drill right out of the box and the coating had to be ground off, but that doesn't sound like the case here since it wasn't the first hole. Spinning a bit that isn't cutting after the fluid starts to smoke ( you did use cutting fluid, right? Having said that I often cheat and use WD-40 instead... it smokes quicker so you stop sooner.) is just asking for trouble and won't drill any holes. I had one of those cheap bench mount sharpeners (utilizes the grinder) but all it did was teach me which angles to hand hold at. The small bits I just sharpen at a single angle and they seem to work fine.
Reply:
Originally Posted by Flyer58
3/16 bit on a drill press at 2030 rpm.
Reply:I did use cutting fluid, which I called oil earlier, and set the speed based on the decal on the drill press. The metal is actually 1/8 mild steel but my handy dandy thickness gauge is in decimal and gauge. I'm totally sold on the idea of getting a sharpener or at least watching a few videos about how to resharpen the bit I have. I appreciate everyone inputDrill press recommended RPM:
Old Lincoln Weld-Pak 100 MIG conversion Vulcan 220 Omnipro
Reply:I think Tubalcain said in one of his vids. If you can't see the flutes you are too fast. I do most of my drilling on my Bpt Mill. I use that rule and seems to work great for me.www.tjsperformance.comDynasty 300 DXHTP 240HTP Microcut 380Hyperthem 85JD2 Hyd Bender and HF Hyd Ring Roller all in one =(Frankenbender)Bpt. Mill/DRO4' x 8' CNC Plasma TableInstagram: tjsperformanceYT: TJS Welding and FabricationOn mild steel you should produce ribbons, not chips.
Reply:Using a sharp bit, try it on 900 and 570 rpm. I think you will leave it on 570 rpm when you see the difference. I doubt you saw any ribbons at 2000+ rpm. I know your bits will last longer.Burt _____________________Miller Syncrowave 250Millermatic 211Miller 375 Plasma Cutter Hobart Handler 120www.10FtDrillBit.comwww.MyWelds.com - pictures of my work
Reply:Perhaps look at the chart as up to the drill size, so 1360 would be recommended. My drill was altered for drilling large holes and using hole saws. So, I drill everything at 100ish rpms. Slow for small drill bits, but beautiful to always see ribbons being produce and positive progress.
Reply:I agree that "slower is almost always better" -- for the simple reason that you're less likely to overheat the bit and/or harden the workpiece -- but I believe there is also such a thing as "too slow." I'm not a machinist, but I believe that if you go too slow, things can get "grabby," potentially breaking the drill bit, mangling the workpiece and injuring the operator...I'm always careful to fixture/clamp everything down good when using slow cut speeds. There's a LOT of torque at the chuck when you step down the "gear ratio" so much.Last edited by StandarDyne; 19 Hours Ago at 08:27 AM.
Reply:
Originally Posted by Flyer58
I did use cutting fluid, which I called oil earlier, and set the speed based on the decal on the drill press. The metal is actually 1/8 mild steel but my handy dandy thickness gauge is in decimal and gauge. I'm totally sold on the idea of getting a sharpener or at least watching a few videos about how to resharpen the bit I have. I appreciate everyone inputDrill press recommended RPM:Attachment 1742226
Reply:This old Tony has a pretty good sharpening tutorialMillerMatic 252, HTP 221 w/cooler, Hypertherm PM45, Lincoln IdealArc 250 AC/DC, victor Oxy/Acet"I'd like to believe as many true things and as few false things as possible"
Reply:When doing a lot of drilling in A36 using a 3/16" drill bit I use 1800 to 2000 rpmDave
Originally Posted by MetalMan23
You should have been drilling at less than 1300, so 900 if that's the next speed downSent from my fab shop using a mig welder and a grinder
Reply:Need a battery drill for hand drilling, I realize there are other ways and lots more guys know way more than I do about it but not many beat me up when it is time to punch a few holes in a strip. I hand drill host things even in the shop, small holes with odd setups are just so much faster on the bench or in a vise vs truing to fit everything in a jig on a press. Again I understand other ways of doing this but I grew up with the same thing, my first drilling wasnt what it is now whare I get feel for speed and prtessure and regulate easily with battery drill and also much safer on larger holes as the tool is power limited. As I mention, I drill most all of this dry and often use a few drops of water if I wanna cool but I am finishing and painting and dont want that crap all over my shop, if it ruins a little bit, oh well, if I gotta sharpen a bigger on so be it, like a grinding wheel just part of the cost, when it becomes cheaper I toss. I buy the small bits for a dollar and they are those noresman ones USA and simply get a handfull on occasion, be different if they were 5 but at a dollar, 2 for a 1/4, bought 10 and going to get 10 more this year a size up. They get lost, spread out, ruined, sharpened on occasion. I got an index, a couple with all the sizes but got a tackle tray on a bench with pile of bits and use all those for the rough fab. I am so accurate hand plasma I blow a lot of holes with it, I got to be careful to make them big enough, can do it to near thread a bolt in.www.urkafarms.com
Reply:I need to get another can of Rapid Tap, good thing to have on hand but use it a few drops at a time and can use it right up at the end of a cut without running all over. A lot of my dripping really does end up in chips,,, but,,, its relatively fast and there is a hole when I am done, I dont care about a curled chip at the finish,, I want the hole and it really doesnt know if its the proper way or not. I dont always go so fast but I timed a "what could" time with actual drilling, already had the pilot and 3/8 thick with 3 drops per 1/8 and could cut this 1 1/8 in 40 seconds. Now,,,, there are other ways, better bits I am sure, some more perfect scheme involving lots morre tools and a whole puddle of fluid but aint no way, no how to do this in place this fast and accurate with as few tools and economical as this.
Attached Images
Last edited by Sberry; 17 Hours Ago at 10:05 AM.www.urkafarms.com
Reply:In the case of the op,,, overheated the bit, too fast, too long mayube, not enough pressure at the right time, etc but most likely a combination of that and burning the end of the bit in to a hard admix left in the hole, drilling from other side with new was easy,,, not a real huge mystery.www.urkafarms.com
Reply:I try avoiding any type oil for drilling steel it is one thing that needs cleaning before welding and or painting. When do use cutting that need cutting I just use pipe threading Dave
Originally Posted by Sberry
I need to get another can of Rapid Tap, good thing to have on hand but use it a few drops at a time and can use it right up at the end of a cut without running all over. A lot of my dripping really does end up in chips,,, but,,, its relatively fast and there is a hole when I am done, I dont care about a curled chip at the finish,, I want the hole and it really doesnt know if its the proper way or not.
Reply:I generally wipe off the oil after I'm done drilling. Paint sticks better that way.
Reply:I am hesitant to use cutting fluid when i punch or drill, since it will need to be cleaned off. I used soapy water on my lathe once for aluminum machining, the resulting red/ orange finish has lasted about 15 years.
Reply:I tried soapy water and its cheap and works well but the resultant rust on iron worker, drill press and vises wasnt worth it. I now prefer petroleum based coolants followed by a wipe down with stoddard solvent. Sent from my iPad using Tapatalk:
Reply:Sounds great But try that with 20 to 100 tons a month in steel. Even brushing oil take time. If doing a little projects I will use cutting oil.Dave
Originally Posted by tapwelder
I am hesitant to use cutting fluid when i punch or drill, since it will need to be cleaned off. I used soapy water on my lathe once for aluminum machining, the resulting red/ orange finish has lasted about 15 years.
Reply:Well this was my first attempt at sharpening a 3/8 drill on the bench grinder. In some ways it was easier than expected but I also determined I needed to be a bit more exact when getting proper alignment, angles and straight edges so it will take more practice and a lot more time if i try making a split point using my Dremel. I also need a better magnifying glass and some accurate measuring tools. Small diameter bit aren't gonna happen at this point without a dedicated sharpening tool. Maybe with better reading glasses.Here's the cutting results, dry and the press set at 900 RPM. I think there were two ribbons but I stopped when something flew off and I could never find it so it's possible only one edge was cutting.
Last edited by Flyer58; 9 Hours Ago at 05:58 PM.
Reply:The titanium coated bits are very brittle and chip often. I prefer to sharpen them lightly more often than to wait for them to go dead.The harder you fall, the higher you bounce...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:
Originally Posted by StandarDyne
I agree that "slower is almost always better" -- for the simple reason that you're less likely to overheat the bit and/or harden the workpiece -- but I believe there is also such a thing as "too slow." I'm not a machinist, but I believe that if you go too slow, things can get "grabby," potentially breaking the drill bit, mangling the workpiece and injuring the operator...I'm always careful to fixture/clamp everything down good when using slow cut speeds. There's a LOT of torque at the chuck when you step down the "gear ratio" so much.
Reply:You got chips 🍟. I have been sharpening drill bits since the 1960's. Great job 👏 👍 👌 Dave
Originally Posted by Flyer58
Well this was my first attempt at sharpening a 3/8 drill on the bench grinder. In some ways it was easier than expected but I also determined I needed to be a bit more exact when getting proper alignment, angles and straight edges so it will take more practice and a lot more time if i try making a split point using my Dremel. I also need a better magnifying glass and some accurate measuring tools. Small diameter bit aren't gonna happen at this point without a dedicated sharpening tool. Maybe with better reading glasses.Here's the cutting results, dry and the press set at 900 RPM. I think there were two ribbons but I stopped when something flew off and I could never find it so it's possible only one edge was cutting.
Reply:
Originally Posted by smithdoor
You got chips ��. I have been sharpening drill bits since the 1960's. Great job �� �� �� Dave
Reply:I was buying a gross of drill bits and reshaping. So paid big time to reshaping .Try contact tips. I would throw a boat load till one I ran out. The welder need one as got to close to work with tip and weld the wire to tip. I remove the cup took grinder and ground back the bad spot and he keep welding. The only other option was stick and I only that could weld stick and 1,000 of pieces to weld. Hard to keep employees working when your under the hood. They will stop and watch you welded.Dave
Originally Posted by Flyer58
Thanks! LOL. Not the first time I've ended up with chips. My avatar is a potato chip like the first time, 25 years ago, when I welded a square tube door frame and didn't know about distortion and how to minimize it.
Reply:We used to dril a ton of contact tips, being copper a dull drill would snap almost immediately, we drilled them in a lathe with a collet setup, usually .045 tips that we'd punch to 1/16.NRA LIFE MEMBERUNITWELD 175 AMP 3 IN1 DCMIDSTATES 300 AMP AC MACHINELET'S GO BRANDON!"Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety. BENJAMIN FRANKLIN
Reply:I remember Bernard had some wrongly labeled Centerfire tips. Customers couldn't understand why the wire wouldn't go through their new contact tips. Things like that can make some customers pretty irate... and for good reason.
Reply:
Originally Posted by Sberry
I need to get another can of Rapid Tap, good thing to have on hand but use it a few drops at a time and can use it right up at the end of a cut without running all over. A lot of my dripping really does end up in chips,,, but,,, its relatively fast and there is a hole when I am done, I dont care about a curled chip at the finish,, I want the hole and it really doesnt know if its the proper way or not. I dont always go so fast but I timed a "what could" time with actual drilling, already had the pilot and 3/8 thick with 3 drops per 1/8 and could cut this 1 1/8 in 40 seconds. Now,,,, there are other ways, better bits I am sure, some more perfect scheme involving lots morre tools and a whole puddle of fluid but aint no way, no how to do this in place this fast and accurate with as few tools and economical as this. |
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发表于 2022-8-7 15:51:38