How I Reuse Broken Endmills In My Workshop - Don't Throw Them Away
G'day everyone,
Since having gotten the mill I have ended up with a little collection of broken endmills. If you use these tools, you're going to break them. Even in their broken state they are a good source of high speed steel which is a great tool steel. In this video I will show you some of the things I have used these broken tools for in the past few months.
Timestamps
0:00 - Introduction
1:21 - Reuse Them In The Mill
2:09 - Use Them As Hardened Pins
2:45 - Use Them As Lathe Tools
4:19 - Lathe Tool Holders For Endmills
5:07 - Lathe Tools I Have Used
6:16 - Using Endmills As Boring Bars
6:43 - HSS Rotary Broaching Tools
7:26 - Tangential Tool Attempt
8:39 - Internal BSP Thread Cutting Tool
9:10 - Centre Drill Deburr Tool
Recycle High Speed Steel
#DIY #Workshop #HSS
I use broken carbide endmills as gage pins, most of the dimensions I make things to are round numbers and the shanks are usually ground to within a very tight tolerance so is perfect for this use.
I think it's worth mentioning that quite a bit can be done with old files that are worn, and I've had a great luck making form tools out of old fashioned screw plates. And I know the conventional wisdom is to avoid mystery steel, but my favorite boring bar for over a decade now was made out of the forged forks of an ancient miniature crane. It's ugly but it holds an edge like nothing else. We spend so much for the simplest tools in this hobby, this is wise to make use of it down to the chips. And then recycle those.
Once again I find myself repeating what I sain in previous comments - your videos are spectacular. It's very refreshing to see the likes of yourself and Quinn from Blondihacks do hobby level machining videos for the likes of myself who haven't quite got the space or the money for a full on bridgeport/colchester machine shop. The frequency of your videos is also astonishing. Really shows a fantastic work ethic. Please keep going, Mr. Artisan. Loving the work.
Well... I'm using worn out small size endmills as boring bars in the CNC lathe, when there's a need to bore a conical surface in some really small diameter holes, like 5-6 mm... Just putting the most good looking cutting edge in upwards position, setting a tool offset for it, and it's ready to go.
Some of my favorite tools are made to utilise broken or odd stubs of hss and carbide. Fly cutter bodies are easy to make and can be very effective. Some of mine I have used weekly for near 30 years. You only need a bench grinder - and some polishing stones or diamond laps used to refine the cutting edge - to made an endless variety of special purpose tooling. Learn to grind your own tooling. Spade drills, left handed drills made from junk etc can really save your day. Want a radius or chamfering cutter to use in your boring head on the mill? A broken end mill may be just the thing with a flat ground on it to seat the clamping screw. Another source - HSS drill blanks are cheap and come in a huge range of diameters. I have a boring bar tool body and bushing set i made to clamp a range of micro boring bars made from small drill blanks.
This is a good way to re-use broken endmills! We did it that way, too. It would be a pity for the good material. And last but not least, it saves money!
As always, great content! I’ve made a bunch of different things from old HSS, including center punches for specific hole sizes.
Always like your videos. I’ve turned a broken center drill into a lathe center. Works well enough and it does not ever seem to need sharpening
Good and appropriate use and recycling of still useful cutting materiel. Well done! Thanks for sharing!
I think drill shanks are fairly soft. I've heard (from the internet) that the shank is intentionally left soft. It could be so the hardened jaws of a chuck can get a really good grip. Anything with flats might be harder but it probably depends a lot on the brand.
That is my understanding of it, but also leaving it softer would also give the cutter bit more toughness. But what I've experienced really depends on the brand's and sizes if endmill
theyre usually left soft because they would damage the chuck if both chuck jaws and drill bit shaft were hardened :)
Many years ago I used to work for Clarkson Tools who made the 'Autolock' range of milling chucks and cutters. Cutters larger than about 3/8" diameter tended to have the flutes milled into soft blanks and then had only the flute areas case hardened using a molten cyanide salt bath - these case hardened tools can be recognised by the milled finish left on the flutes. Smaller diameters tended to have the flutes ground into pre-hardened blanks and these would have the same harness values for both flutes and shanks. This also applied to other milling cutter brands that were owned by Clarkson such as 'Qualcut' - these tools were identical to the 'Autolock' brand using the same materials and produced on the same manufacturing line with only the final stencil marking differing to cater for customers that preferred one brand over the other.
The shanks undergo induction heating. That's why they are softer. About 3 minutes into the video... kzhead.info/sun/Y8dvj6qFjIqHmmw/bejne.html
Yeah it doesn't work that way with carbide. Solid all the way thru, maybe with a lack of coating on the shank, however.
I use 1/8 carbide tools to make tips for scribes. Spin it in a drill to make a nice point on the grinder, and use a piece of aluminum or whatever to make a handle.
I never saw you using that "white grinding wheel" to make your tools. Since I've tried that stuff to grinding my tools I've never changed. It's made for hard metal, and it gives you a better finish for the edge of the tool and save time as well, because you don't need to normalize the material. Try that if you have the opportunity. Great video!!!
Clever reuse. We shared this video on our homemade tools forum this week 😎
Some neat ideas here. Thanks for posting!
Great info as always, thanks for sharing Cheers
I haven't bought more than 3 HSS sqaure shanks in my entire life of machining. Been doing it for 20 years. I asked my boss if I could take the scrap HSS and carbide inserts home and was told yes we don't have enough to make recycling worth it. I have lots of everything.
Nice work and a great video. I too re-purpose drills and mills . Last time I made an inside grooving tool. Another source of tillage is those threading insert from a threading tool, they have a left hand geometry and can be easily adapted forturning a right hand thread from left to right with tool inverted and reverse rotation ( ala Joe Pie). Enjoyed, thanks for the video and cheers!
I often sharpen broken centre drills and use them as a centre punch which works pretty good
These are great tips! The really small pieces can still be braised and used that way. I've never really understood why one is not supposed to use end Mills on the lathe. One of my favorite Time savers it is an enormous one inch by 7-in solid carbide end mill with fairly square corners. It's junk from off of eBay, but it's decent enough carbide to hold up forever. I made a taper shank arbor for it, it's in my tail stock more often than not. I've completely quit drilling the small holes and working my way up, I think this is far more efficient although I recognize most books disagree. I don't know if these are available in your country, but they're very easily spotted on us eBay. They are always located in towns far too small for any manufacturing and the prices are typically a quarter of any known brand. They are junk if you are expecting a solid finishing tool. They're fantastic if you're looking for something to abuse and smash through work.
They are also very good as securing pins for templates, gigs and the like 👍
I always love your videos. Thanks.
some great ideas, thx :) I usually use broken 1/8 tools to make scribing tools (have a video on that). Keep up the great work 👍
I like the behind the scenes, set up operations, and your commentary on machining. Great video as always
Good vid! Very useful. Thank you.
Someone's gonna find that deburring tool in the future and think you were drilling centers by hand, lol
They can be hand ground to a fishtail shape. Use a small trisquare to get the two cutting tips even. These kind of cutters are sometimes called slot cutters and work very well cutting keyways as the shape pulls the cutter in.
New subscriber. I too keep broken tooling for this purpose.
I make my own lathe tools from broken or dull endmills.. Since i use CNC machines i regularly use 4mm endmills in Titanium, going 10 mm deep per pass, using HSM toolpaths. When they break or get dull i regrind them into Cutting inserts on the lathe. I use a Diamond Cupwheel on a cheap manual lathe that is mostly used as a tool grinder nowadays.. I made my own holders as well, these work fine, i use these on all materials. With a Cupwheel on my "Makeshift Toolgrinder"i can also make boringbars.. indeed Ø4 mm boringbars..
Thanks for sharing
AFAIK nowadays HSS endmills and drill bits are often not solid HSS but a HSS business end welded to the mild steel shank during the production process. That may explain why shanks are often impossible to get hard enough. Often you even can see the weld line because of colour difference
On my desktop cnc. I use broken end mills as indexing pins to locate parts. I started out using drill bits but they just didn't have a proper diameter. I found end mills are a lot more true to advertised size.
Very good 👍👍👍
Made a one off lathe tool bit from a chunk of broken carbide. Been using it for years now.
Very Nice. I do the same with broken taps
I like to keep some of my broken or chipped taps to grind back to use as bottoming taps after using a good tapered or gun tap. Also for cleaning out dirty or damaged threads to save my new ones.
I have a little box full of broken endmills and use them to make scribes, lathe tooling. Hell my favorite cutter for the lathe is an old endmill.
Good video, as a reward I'll give you another handy mod. On the shank end of your drill bit grind a fairly broad point, angle is not critical, but you don't want to have an excessively long taper. Now you can use a soft hammer on your new precision transfer punch set. Plus you haven't had to wait for dead drill bits to make them :)
When I was “on the tools” we used to harden HSS and “silver steel”. Heat to a very dull just barely red, water quench, then temper to a straw yellow.
I'm thinking of making a hole transfer punch from the stainless steel shafts or drill bits. I will need to harden the tip after making it look like a pencil tip on a lathe. do you think it's doable? how to harden the stainless steel shaft tip to last and remain sharp?
Thank you, to see that someone else also has full box of these broken low diameter fu*kers makes me feel better. 😀
Thanks
You can also grind carbide ones into amazingly good scribes.
Use broken drill bits and tools or even springs for hard steel that you can fuse to anything, and make very hard tools. I quenched in water immediately while glowing hot, without tempering and unsurprisingly the tool steel that was melted onto regular steel, was unbelievably hard and durable though brittle.
Very good video!!! Lovely!!! My comfort point - at least not only my tool grinding look bad... ;) Just protect your lungs - carbide dust is toxic!
I have been collecting broken tool too because I now there good steel. Now I have ideas of what to do with them besides as tool chest ballast😂s
Good 👍👍👍👍👍👍
Broken carbide shanks for grinding carbide spade drills. It can drill through taps and drills.
All ways thought about grinding them into tapered square style easy outs but haven’t tryed yet.
what about the round inserts? for what are you using for on the mini lathe???
I don't have any broken end mills but I do have a good number of blunt endmills.
You need a cutter grinder. If you don't wanna invest in a good one. Just go for the attachment device and figure out to combine it with your toolpost grinder. Or a bench grinder. You can make some pretty awesome cutting edges once you get the hang of it.
What coolant are you using, what ratio isit?
Careful grinding carbide, it's definitely gnarly stuff.
You don’t run into balance issues doing this?
never tried with broken end mills but you can use broken drill bits as hardfacing rod.
I have tried forging old end mills. It crumbled when you hit it when hot. Sort of scary
Use quenching oil for hardening those bits, you will achieve much better results.
It's not the quench medium that's that issue, it's the soak time and cooling rate needed for M2 hss which I can't do in the home workshop. If anything water shouldbe given me more hardness which it didn't.
I'm gonna take it in mind Hss and specialy carbide for sure are useful Btw I'm looking for a 600-700 mil and 500-600 USD (if it can be purchased in Amazon it will be even better)
sometimes we grind them so that we can use them as engraver bits
BB endmill, from aliexpress. But they are good
You can heat up the shank to a dull yellow glow, let it aircool and it should harden up just enough
I have tried this method but i just can't get it to achieve a good result in M2 grade
@@artisanmakes It needs to go above 1150 degrees celsius for any hardening to occur
My data sheet says about 1190 celcius or there abouts.
welding them together to make a longer drill bit...
To hardening use old oil from diesel oil change. Filter it using a coffee filter.
M2 hss requires very specific heating and soaking times to properly harden, which is why I have has little success doing it in the home workshop. Cheers
Does this work with broken taps, there carbide or high speed steel will they work?
I don't see why not, it's usually pretty hard hss
You can harden the steel, just get a color table from the Internet for your steel. And for youre tools that you make with the grinder, you should take a look at the specific angles
Like i said in the video the process is different for HSS. I've tried similar methods that I use for carbon and CRV steels but I don't get the same results from HSS, especially M2 grade. I have been taught about the basic process about how HSS is hardened and it involves preheating, heating and quenching at very specific temperatures and conditions to obtain the correct hardness, something outside the scope of what I can do. And for tool grinding, those angles are useful, but for hard to cut alloys, those guides can sometimes go out the window. The boring bar I made probably would do poorly in a 6000 series aluminium, but worked perfectly for cutting a 4000 series.
What do you mean by lock the table at 0:22? If you lock the table, how will you mill?? I don't do any milling, I did it a few times back in college and now i only watch videos of milling.
You lock one axis, the one that you aren’t travelling to stop the it moving either under vibration or due to the small amount of backlash in the lead screw
@@artisanmakes okay. Thank you.
I use a small diamond grinder to make single lip engraving tools and small radius tools from mostly 1/8" mill shanks that the cutting surfaced blew off of. Getting an old deckel grinder is a great idea too, as you can often pick them up for a song, and they are great for "pyramid" engravers.
Tell me the correct song to sing for a Deckel! They are extremely expensive!
@@bigmotter001 The one our shop uses is actually broken. It no longer can do the relief, but the wheel still spins, so we use it for pyramid engravers quite a lot, and single lip tools.. well I am just careful when I relieve them by hand on the diamond. If "broken but still useful" is still too expensive, look into the "quorn" grinder and other home made versions. You can build some of those for about 3 times the cost of the wheel they use if you are frugal and have scrap lying about...
I'm a blacksmith and we had to learn to harden High Speed steel. It is a lot more involved than just hardening and tempering medium to high carbon steels. I haven't even tried it since learning it in school many years ago. It is a lot cheaper to buy blanks and grind tools from the blank.
I agree, I've never hardened hss, but I learned about the process, and it is very much outside the scope of what I can do.
👍👍👍
if you wanna harden em with a torch like that you'll probably need to grab an acetylene or map torch instead of the butane. its just too cold to get it to temp in the open air. if youve got an enclosed space thats fireproof butane/propane can work. good luck!
From what I understand, the issue is moreso the soak times and cooling rates needed to harden M2 hss
a normal 6mm's shank is normally ground to 5.996 ( at lease the few 100's of carbide ones i mesured with a mic and cmm ( cmm said 5.9965 but the temps wasent right to trust it that much so i just said 5.996 was wha i belived )
Interesting you struggle to heat treat HSS. It is one of the simplest steels to harden ,being an air hardening tool steel, literally get it cherry red and toss it on the bench and you will get 62 rockwell. Maybe your gas torch isnt getting there temperature wise. I have used it a lot in my blacksmithing activities, as buying lathe tool blanks from China is a good cheap source of HSS for making chisels and knives. This would of course also be a good use of broken tools.
It really depends what alloy you are referring to. I have not had much luck with M2. I have a handbook which details how M2 should be hardened and it requires soaking and quenching and specific temperatures to achieve the hardness and toughness. Stuff outside the scope of what I am able to do
Merhaba ustam şişenin içindeki ne yağı
The video angle may deceive, but: At least 08:30 it looks like your tool-holder is binding to the work piece. Are you sure the tool-holder has enough clearance?
It could be like this, there wasn't much clearance at all with this set up, especially when I got to a shoulder. Seeing as it couldn't get a nice cut I abandoned this idea, if it worked I probably would have cleaned up the holder to give me more clearance. Certainly wasnt rubbing when I was turning the shaft
2:25 I'm dead
We don't throw them away in my shop either, oh wait I don't have a shop...
I use broken end mills to drill out broken screws, bolts, ect...
My understanding is that these tools are heated, then cooled to create a certain strength. Some data I ran into showed that even after cooling, meaning on a later date, you can cool the tool further for more strength. But strength also means brittle. So you need to know which tool you want to keep in the freezer lol. Interesting thing to know though, that you can keep cooling it at a later date with very similar results.
Of course it is like this, but hss has specific steps for heat treating that I can not do in a home workshop, as a rest I've never gotten great results from trying to hear treat hss
@@artisanmakes thanx for replying, I like the sarcasm in your vids, I’m pretty sarcastic too, and not everyone gets sarcasm, but it’s hella funny to us that do
@@artisanmakes oh and I meant in terms of the cooling process, that you can continue it. Makes me wonder what would happen if you took a new piece, stuck it in liquid nitrogen and then stuck it in the freezer for a few days, to then take out and let it warm up back to room temperature. Idk but keep up the vids
👍💯👍.
If you are going to make your iron harder then you should cool it in oil not in water then your iron should be harder. Greetings M from Belgium
I get where you are coming from, I only did it here to demonstrate that quenching the drill bit even in water didn't effect it much.
👍😎👍
Just use em as pins fpr setup or resell the material. As a shop owner you have to consider the cost of making something out of a 50 dollar endmill. Say it takes a guy that you pay 20 bucks an hour to make a tool out of an endmill and it takes him a half hour. You spend 10 bucks having him make a tool that probably costs 10 bucks to just buy. Now consider the time that this guy could be using to run a machine that makes you 100+ an hour. That 10 bucks is now $60. Remember your endmill was only $50 to begin with. You're now -$10 in the hole. For a hobbyist, sure. Do whatever you want. But running a shop I wouldn't bother making anything other than a pin because the pin is already technically made the second the endmill breaks.
This video isn't really aimed at production shops. This channel is just a hobby for me. Most production shops I've been to dont really use hand ground tooling anyway. Mostly insert tooling from what I have experienced.
@@artisanmakes yeah, as a hobby I get it. You'd be surprised though how many times I've had to explain that concept up there to shop owners because they didn't have a clue how much money they were wasting. A lot of people only see the upfront cash but fail to recognize how much money the wasted time costs.
Dont stop your imagination!
At 2:35 was that an amogus?
Yeah, an enamel pin I made for someone a while back
wait, what? end mills can break???
There's a lot of boring bars ya got lying around there.
⚠😆👉This is not a drill ➡🔨 and not all bars are boring!
What???? BSP threads are 47.5 degrees Whitworth threads are 55 degrees.
Nope BSP are 55, search it up
BSP uses the standard Whitworth thread form with 55 degree threads. You may be thinking of BA (British Association) machine screws?
This guy needs to check his facts before posting silly comments,47.5° for a BSP thread? Really!! Think you will find 55° is correct.
Use oil to quench it it's better then using water
I do this to show that quenching didn't do much for hardening the hss. Water quenching should give us a higher hardness than oil but did not do anything. And there are reasons why I might choose a water quench over oil in certain situations.
hgf
Feeding in the wrong direction to the rotary detection of the tool lol, common knowledge ate worst lol
I do most of my milling conventional. I forgot to lock the table which pulled the tool into that front face which I wasnt milling
Climb milling broke that endmill...
Well it climbed on that front face. The side the I was milling is all done conventional.
For the last 20 years climb milled just about everything. Definitely on cnc production machines but more often for me in Bridgeport style machine. Better tool life and finishes. Make sure you have enough drag set on the slides to beat the back lash. Not what I was taught in college but works for us in our shop. Sure - you may not have enough rigidity in a home hobby mill drill. Feeding smoothly by hand especially requires practiced technique.
@@johnhunt6992 What works for you, but you are right, this machine isnt really set up for heavy climb milling. I most use it for finishing passes. Cheers
I see your lathe is stalling. There's no reason why you can't use a 1hp 3ph with a VFD. My 1943 South Bend came with a 1/4 hp I switched it to the above.
$30 end mill? JAJAJAJA try 300+ on the larger ones we use, and they break just like the cheapos.
Every sentence ends with him adding ugh to the last word. Really annoying