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Quality Drill Bits


Obadiah Blank

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Who makes quality drill bits and where can I get them from?

Should I buy the 5% cobalt ones even if I'm just doing mild steel, and if so, which cutting fluid should I get?

It was before the internet and cheap chinese knock offs since I've had to buy any quality drill bits. There is now such a wide choice, the shops I trusted have shut down and alot of the old quality companies get their products manufacturered abroard without much care for quality control. So, although in most cases you get what you pay for, you can also get ripped off.

Cheers,

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Thanks guys. I'll have a go with the DeWalt/Screwfit option, just getting one to see how it goes before investing in more.

What do you think of cobalt drill bits?

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High Speed Sfeel (HSS) drill bits will suit mild steel. Engineering supplies and Tool hire shops will have a good range.

Cobalt ones can be used as well but are really for stainless steel.

Cutting paste would be a bonus and you can get away by drilling dry as long as you don't overheat the bit which is usually due to excessive rpm speed.

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You just want a set of decent HSS 'Jobber' drills if you are using them in hand equipment. Harder drills are great in the right machinery but chip and snap quite easily.

Presto and Dormer were always good and they reground quite well too.

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I like Guhring drills. Expensive but keep an edge longer than the cheaper ones.

Most of the hss drills on ebay are crap. They are so soft and burn out far quicker than the stuff we use at work (they use presto but I still prefer Guhring and have my own set)

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Thanks guys. I appreciate the advice. I have an old set of Presto which I've had for years but they have long since lost their edge. I'll try the various options recommended before getting a set.

Cheers.

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Regrind them - it's a piece of piss once you get the knack for it and only takes a few seconds per bit.

It's one of my favourite 'chores' and I very rarely have to buy new drill bits. I'll often give one a quick grind just to suit a particular material because it's so easy.

This is one way of doing it.....

It's not quite how I do it but it will work and is much easier to copy. All I'd add is that he isn't cooling the bit between grinds which is important. Overheating the steel will soften it.

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doing by hand is ok, but you will never get it exactly right so it will always cut oversize. this may or may not matter to you, but i always use a new drill if i'm bothered about the size

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Dont buy those drill bit sets they flog off at the bike shows like the NEC etc, you know the ones they demonstrate by drilling through anything and everything, there shit!

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All of the above is all good stuff.

If you want to put a hole in something you can sharpen fairly well by hand if want to make a hole and put something in it the some way of accurately sharpening will be a necessity. Check this out if your interested in simple sharpening:

http://homews.co.uk/page354.html

And here if you want to get serious:

http://www.gadgetbuilder.com/DrillSharp.html

To be honest though drills under 10mm are fairly affordable and have geometry that is a little harder to recreate than older drills, so I would buy new most of the time.

High quality: greenwood tools do a guhring set which has a few tapping sizes too, never used them but when I've seen them at shows they look the business.

http://www.greenwood-tools.co.uk/shopscr87.html (At the bottom)

Personally though I go with toolstations cobalt ones. Buy the size you need when you need and eventually you wind up with all the drills you need and they stand up to abuse.

http://www.toolstation.com/shop/p99309

Cheers

Martin

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doing by hand is ok, but you will never get it exactly right so it will always cut oversize. this may or may not matter to you, but i always use a new drill if i'm bothered about the size

Fair point but for critical drilling, I'll always go up in stages unless it's a really thick bit of metal. I'm always starting with a new or very good pilot or even centre drill to establish the right position.

I suspect that you, like me, have got some lovely sharp 'keep yer mitts off, you pleb' drills and reamers for those truly special occasions.

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  • 2 weeks later...

doing by hand is ok, but you will never get it exactly right so it will always cut oversize. this may or may not matter to you, but i always use a new drill if i'm bothered about the size

You need more practice if you're not getting it to cut size...........

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