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Drill bits

  • 03-12-2022 6:23pm
    Registered Users Posts: 24,229 ✭✭✭✭

    Looking for recommendations on a good set of metal drill bits for a pillar drill.


  • Registered Users Posts: 1,997 ✭✭✭DBK1

    Ruko all the way. They’ll be a bit dearer than any of the rest but well worth it.

  • Registered Users Posts: 24,229 ✭✭✭✭Reggie.

    Cheers. Price won't bother me as just want decent ones

  • Registered Users Posts: 4,875 ✭✭✭zetecescort

    Using some sort of lubricating oil or the proper cutting oil just as important as quality of bits

  • Moderators, Society & Culture Moderators Posts: 12,459 Mod ✭✭✭✭blue5000

    Dormer is another brand to look at too. Might be made in Brazil now but still good.

    If the seat's wet, sit on yer hat, a cool head is better than a wet ar5e.

  • Registered Users Posts: 24,229 ✭✭✭✭Reggie.

    Agreed but there are fair differences in bits tho

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  • Registered Users Posts: 1,395 ✭✭✭mr.stonewall

    Go for the cobalt version if the have them. Drill speed is the key to minding bits. In a pillar drill bits just last longer the work is fixed. Less chance of the bit moving while boring

  • Registered Users Posts: 2,617 ✭✭✭Schwiiing

    I agree with everything in the thread in terms of Ruko, keeping it lubricated and learning how to set the speeds on your drill but I'd also mention learning when and how to sharpen the bits. Small bench grinders aren't crazy money or you can get special bit sharpeners. Takes a small bit of skill and experience to know when it's perfect in terms of your angles etc.

  • Registered Users Posts: 1,001 ✭✭✭timple23

    Bought these Milwaukee thunderweb ones off amazon. Haven't managed to break one yet and have drilled through a good few pillars, definitely a value for money set. One thing I must get is a set of left hand drill bits, told opticut is a good brand but can't find them in Ireland.

  • Registered Users Posts: 1,670 ✭✭✭Gen.Zhukov

    This is one of the better cutting fluids - It's not cheap, but it is excellent

    + 1 on Ruko and +1 on learning to sharpen bits properly

  • Registered Users Posts: 3,262 ✭✭✭MfMan

    Sharpening bits is a skill I have yet to acquire. Which is better, a flap disk or grinding stone for sharpening? Anyone use drilling paste rather than fluid when cutting? Any good if so?

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  • Registered Users Posts: 1,273 ✭✭✭older by the day

    Most of us are using our bits wrong. Heating the bits. Instead of buying sets of bits and being left with all the tiny ones. Buy a few of the sizes you want

  • Registered Users Posts: 10,516 ✭✭✭✭Say my name

    Then there's Thermal friction drill bits that don't have a cutting edge but rely on friction and heat to push through.

    Mad looking yokes altogether.

  • Registered Users Posts: 1,670 ✭✭✭Gen.Zhukov

    Sharpening with a fine grinding stone on a bench grinder. I've used Trefolex cutting paste. I'ts ok and relatively cheap but deffo not as good as the fluid I linked above

    Yeah, the flowdrill system. Great for production runs where you're tapping a thread into the piece afterwards.

  • Registered Users Posts: 685 ✭✭✭Mach Two

    In order to get the correct angle get two hex nuts and place them side to side and that will give you the correct angle for sharpening a drill bit.

  • Registered Users Posts: 10,304 ✭✭✭✭patsy_mccabe

    I have a set of diamond files I got in Lidl for €5. I find them great for getting the edge back on a drill bit.

  • Registered Users Posts: 809 ✭✭✭dohc turbo2

    The majority of bench grinders are set up for bit sharpening, most have a spot the bit sits in on the metal bracket in front of the wheel

  • Registered Users Posts: 2,745 ✭✭✭SuperTortoise

    No need to go mad expensive with them, a decent quality HSS bit is plenty good enough for drilling anything around a farm.

    I went a bit mad last year and bought a split point cobalt set, a waste of money for the drilling i'd be at and not worth the extra price.

    As others have already said, keep them sharp, use lube, learn how to sharpen them if you don't already know.

    Also consider what size bits you need, "standard" sets go up to 13mm which is fine for an M12 bolt, having a set for bigger sizes is very handy as is a step drill bit, spend a bit more money on a step drill bit if you are buying one, big difference in quality in these.

    What pillar drill do you have?

  • Registered Users Posts: 24,229 ✭✭✭✭Reggie.

    Bought a SIP 28-20

    Got it on black fridaty with €300 off

    It'll do any of my drilling

  • Registered Users Posts: 1,670 ✭✭✭Gen.Zhukov

    My sharpening method has worked well for me. I needed to re-jig things with the smaller of my b/grinders anyway so thought I'd log the prep process.

    Took off the tool rest and cleaned with a fine emery cloth.

    I blued it by heating with a blow torch - (when the desired dark colour is reached, dip in used engine oil)

    While the cutting edge angle of a drill bit varies, it seems 118 degrees is the most common - a poster above was pretty close with the 2 hex nuts as that would give you 120 degrees. Anyway, I went with putting a few lines on the tool rest with a scribe and at an angle of 59 degrees (half of the 118)

    I'll try to do a video soon to show how the whole thing comes together and all should become clear. Btw, I had to dress the g/wheel as it had grooves in it and I used the following method, it was great - Wear specs!

  • Registered Users Posts: 1,001 ✭✭✭timple23

    When you say "I blued it by heating with a blow torch - (when the desired dark colour is reached, dip in used engine oil)" is this a way of painting the steel? Or what is the reason for doing this?

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  • Registered Users Posts: 24,229 ✭✭✭✭Reggie.

    It's to harden the steel. Its called "quenching"

  • Registered Users Posts: 1,012 ✭✭✭Tonynewholland

    I just use the angle grinder for sharpening. Just cool down the drill bit in water as you do each side.

  • Registered Users Posts: 1,670 ✭✭✭Gen.Zhukov

    The bluing was really just so the scribe lines would show up better (if it hardened the steel in the process, it's a bonus)

    So here is a still from the vid to explain what I'm at. If I didn't blend the face in, the cutting edge simply wouldn't cut the steel

    I was a little pushed to keep the vids below a certain file size (host restricted) so not as precise as I would normally do it, but you'll get the idea. I notice the vids are a bit jumpy and not as smooth as my tablet playback.

    Note: Don't allow the bit to become too hot and whatever heat you do put into it, do not quench in water - allow to naturally air cool (I got that from a Presto cutting tools Engs booklet I have)

    There's a knack to it which I'm sure you'll get the hang of - Have fun

    Post edited by Gen.Zhukov on

  • Registered Users Posts: 2,745 ✭✭✭SuperTortoise

    "blueing" is creating an oxide layer giving a small bit of corosion resistance and i've seen it done by painting on some sort of a paste, i forget the name of it. I've never seen it done by heating but maybe it can be done that way as well?

    Hardening is heating to cherry red and quenching in oil/water, mild steel cannot be hardeded in this way as it has too little carbon content.

    A rub of a file over the steel after hardening will give a good idea of how hard it is.