Tipsblitz19: Drilling spring steel with HSS drills

[Music] hey welcome back this is my entry for Emirates ins tip blitz 2019 which is a collection of small shop tips we all know spring steel this commercial great spring steel which comes already spring hard it's very useful material it can be used to make obviously Springs but it's also great for where surfaces because it's seriously hard and this relatively precise in sickness rolled you can make parallels out of it thin parallels but it's really it's it's a good base material you can machine small precision parts directly out of it which do not any need any additional heat treat and so on and so on but drilling can be a little bit challenging Mills quite nicely with coated high speed steel or better carbide tooling but drilling can be really a bare grilling with of carbide drill works perfectly fine another problem also I like to use a carbide ball and mill to drill it which leaves a very precise very clean hole but sometimes sometimes you don't have net sometimes all you have is a high speed steel drill with no coding probably Dahle already so you have to regrind it then you need to drill something like this spring steel let's see what happens if we try to drill this normally use a drill drill Chuck I have a piece off cold roll being below the spring steel as a sacrificial piece that's better than wood if you don't do that you you push all the material down and gets all all wonky on you so let's try to drill this let's give it let's give it a thousand rpm it's it's that's relatively slow for a three millimeter drill but theoretically it should roll quite okay [Music] no it doesn't if you run this material anywhere near normal speeds and feeds you have no chance of drilling it with an high-speed steel drill no way so this instantly you get into the material and at some point the tip of the drill rounds over and it's game over you have to reach our pure drill reorganize and then try something else but there is a way to drill spring steel with a high speed steel drill I'm going to show you that this is not going to be a drill grinding video but I'm showing I'm going to show you how I grind a drill so there's relatively small drill I come come in approximately at the angle of the tip make contact with the wheel and then I just tip it back and and push it forward at the same time I do not do this this rolling motion so let's go [Music] so I do this to one flute [Music] and I spin it 180 degree they're together take a look at the tip of the drill and if both cutting edges are reasonably the same size I call it good and this is good enough by the way this rattling noise you hear is not the bench grinder it's this this bandsaw blade I have hanging over to bench grinder so the trick is not to go slow to go extremely slow we're going to run this drill at a hundred rpm and with a lot of force you really have to push it into the material to cut into the hard material and then it will work [Music] the drill won't do this for many holes you will get probably one or two holes out of a resharpen like this in this tough material but if you're in a pinch and doesn't have a carbide tool at hand that's all that's the best you can do you could also use you can regrind a masonry drill rock for drilling rock or concrete to a positive cutting geometry and use that but I had only reasonably success with that the the car the grade of carbide they use on a masonry drill is it's completely different to the normal car right we use in our metal cutting tools so that already worked quite decent but we can even do better with the high speed steel drill so let's resharpen this again okay I'm back from the bench grinder did a normal regrind as usual as you can see and what I'm going to do now is I'm going to split the point that will make the drill cut this material way easier splitting the point is really hard to show I'm gonna using my diamond wheel on the D bit grinder and I do this completely off hand and the idea behind splitting the point manually is to grind with the edge of the grinding wheel into the chisel edge and reduce the chisel edge by a lot okay here's a close-up view of the split point you can see the material I removed here and on the opposing side it's not that symmetrical because it's offhand grind but it's okay for this purpose the idea is that you want to minimize the chisel edge that's the that's the straight edge between the two cutting edges right here in front you want to be you want that to be of minimal length okay back at the moaning I should always make sure when you use a backer piece that when you drill through that you end up in solid material and not in a previous drilled screw hole so let's try this again this time with thin web still at a hundred rpm [Applause] there we go three holes I can already feel that that drill gets dull here again the drill and a close-up after we drilled three holes and you can't see that that there is some edge where which is fully on the cell because material of drillings heart [Music] [Music] this technique works just as fine with with larger drills like this ten millimeter drill leaves a perfectly nice reasonably round hole so let's recap use a backer piece second run crazy slow third user use reasonably large feet pressure you want to take a cut and not rub on the spring steel thinning the web helps a lot learn how to thin the web and there are many many instructions look at pictures how I drove a thin web has to look look at a commercial drill with thin web and try to replicate the grind that's that's my recommendation for tool grinding anyway just let look at commercial tools and try to replicate the grind v do not pre-drill if you want to drill a 10 millimeter hole drill 10 Milnes do not pre-drill it for 3 millimeters and then open it up when the cutting edge of the drill hits the edge of your pre-drilled hole this puts a lot of point stress or point yeah point stress on the on the cutting edge and will wear a deep gash into it and at some point it will just not drill anymore so don't do that just drill to final diameter so I hope you enjoyed my entry for tip blitz 2019 which was initiated by Emma Ritson be also sure to check out all the other entries a lot of youtubers are participating to do machining small machining tips and videos on these tips today thank you all for watching and see you next time [Music]

Channel: Stefan Gotteswinter

Views: 62,633

Rating: 4.961977 out of 5

Keywords: tipsblitz19, tipblitz19, drilling, hss, springsteel, federbandstahl, hard, bohren, ausspitzen, bohrer schleifen, drill grinding

Id: dPlsEMY_HZ8

Length: 10min 50sec (650 seconds)

Published: Sat Sep 14 2019