/ Drilling DMM Fly

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Milesy - on 30 Nov 2012
I have burned out about ten drill bits trying to put on my petzl grip rests. What type of drill bit will get through this? Anything else isnt even making a dent.
wilkie14c - on 30 Nov 2012
In reply to Milesy:
I've heard similar tales of how tough the flys are. Think you'd need a really high carbon steel bit and a low speed, high torque drill press. Know anyone who has access to an engineering workshop to do it for you?
davy_boy - on 30 Nov 2012
In reply to Milesy: best thing would probably be hss-co drill bits as they have a certain % of cobalt in them thats what we tend to use at work for stainless idealy you need a bench drill as you can get a slow speed with good torque. if using a normal drill a decent cutting fluid or grease will help and try using the smallest drill u have to get started.
spearing05 - on 30 Nov 2012
In reply to Milesy: No idea what Flys are made of but doubt it's something a carbide drill wont go through - cheap enough off ebay.

That said what are you using? I know nothing about your engineering skills so forgive me if I'm teaching you to suck eggs. Use a small drill to open a pilot (a little larger in diameter that the web at the tip of you final drill), keep the drilling speed down and use a cutting fluid, normal oil is better than nothing. Most importantly make sure the drill is sharped properly.
spearing05 - on 30 Nov 2012
In reply to spearing05: Or even sharpened
Martin W on 30 Nov 2012
In reply to Milesy: I actually used a small tile/glass drill bit (the kind that looks a bit like a stone age spear) to make the initial holes in the web of the spike on my Flys. I don't know what it was tipped with, I just had it kicking around in my toolkit. Nothing else would make any kind of impression. I then opened the pilot holes out with a Bosch titanium bit, and tidied up afterwards with a small round file.
RichardP - on 30 Nov 2012
In reply to Milesy:
Use a centre punch to act as a centralising point for where your drilling, otherwise the drill bit will drift over the piece of steel

If you buy Tunston Carbide drill bits (they are gold in colour), they are harder than HSS (High Speed Steel) drill bits

I've used these kind of drill bits for drilling hardend and stainless steel

As previously advised use a drill on a slow speed and use a oil, or Tallow (lard) to act as a coolant

It maybe a good idea to step the size of the drill bit.

first of all 3mm, then 5mm, them 8mm upto the desired size
David Cowley - on 01 Dec 2012
In reply to Milesy: B & Q do a titanium or carbon drill bit set for 20 quid ish and he just used a dewelt drill and used some coolant to help with the process. What petzl grip rests are you using? I'm wanting to do the same with mine
wilkie14c - on 01 Dec 2012
Milesy - on 01 Dec 2012
Great advice from everyone here. I will take all on board this week and try again properly :) thank you.
Milesy - on 03 Dec 2012
The 2mm, 3.5mm titaniumm bits snapped in the drill without making a dent. The 5mm just seems to spin, and spin and spin and spin....... christ.
RichardP - on 03 Dec 2012
In reply to Milesy:
Centre punch where you want to drill and use Tungston Carbide (the gold drill bits) as I said the other day.
spearing05 - on 03 Dec 2012
In reply to Richard Phelan: The gold drill bits are generally just HSS with a titanium coating. Tungsten carbide is used in the tips of masonry drills (I've known guys put an edge on one of these for drilling hard steel but you need the right grade of grinding wheel)It is also used for the tips of ceramic drills and on some core drill bits You can get solid carbide drills but they're not the sort of thing you'll pick up from B&Q.
RichardP - on 04 Dec 2012
In reply to spearing05:
> (In reply to Richard Phelan) The gold drill bits are generally just HSS with a titanium coating. Tungsten carbide is used in the tips of masonry drills (I've known guys put an edge on one of these for drilling hard steel but you need the right grade of grinding wheel)It is also used for the tips of ceramic drills and on some core drill bits You can get solid carbide drills but they're not the sort of thing you'll pick up from B&Q.

I wasn't aware that the the tip was used on SDS drill bits?
( I only use SDS Drills on site)

However when drilling stainless steel cabinets on sites like for cable entries we always used Tungsten Carbide Drill bits. (which are the Gold drill bits as opposed to the Black or stainless coloured ones)
So long as you don't let the drill go to fast as so heated up the material and so Harden the metal being drilled you'll be ok.

to explain about the properties of drill bits you could refer to this page.

http://www.ehow.co.uk/about_5112484_hardest-drill-bit.html

cousin nick - on 04 Dec 2012
In reply to Richard Phelan:

I have a set of cobalt steel drill bits (horrendously expensive!) that I bought several years ago for drilling marine grade stainless steel. They are excellent PROVIDED (as Richard has said) you keep the speed down and use some lubrication. I am fortunate to have a drill press, which undoubtedly makes the job easier. I also had occasion to drill stainless underwater, using an air drill, which was interesting, but I've never tried these bits on titanium (they will, reputedly drill Ti).
A good quality bit will make all the difference:
http://www.ttp-hard-drills.com/cobalt-drill-bits-products.html
andic - on 04 Dec 2012
In reply to Milesy:

Sintered tungsten carbide bits are the mutts nuts, a sort of blueish silver colour very hard but brittle and pricey.
http://www.cromwell.co.uk/index.php?q=0&p=browse&c=39151202

The gold coloured bits are just coated with titanium nitride which is very hard and reduces friction but wears away eventually and a thin coating is only as strong as the substrate anyway (HSS probably)

I am really surprised you are having so much trouble i wonder if it is actually rour drill that is the problem?
mkean - on 04 Dec 2012
In reply to Milesy:
Not taking the mickey but are you running the drill the right way?
wupert on 04 Dec 2012
I ran into similar problems last year, trying to drill my flys's with a cheap corded drill on my door step at home.

In the end i took it to the Engineering department at university and they did it in two seconds.

They used my cheap bosch drill bit nothing special just 2 from B+Q.
The man just had a very good old pillar drill, and said its all amount a slow constant speed and pressure, which you cannot get with a normal drill.

He also said the axe i had attempted to drill at home was hardened because i had compacted and heated the metal where i was trying to drill.

Hope that helps,
Martin W on 04 Dec 2012
In reply to spearing05:

> Tungsten carbide ... is also used for the tips of ceramic drills

I didn't know that, but it would explain why my tile drill bit worked to drill the pilot hole for me.

To Milesy: this is the sort of bit I used: http://diydata.com/tool/drillbits/drillbits.php#tile - they're readily available from DIY & hardware shops.
jkarran - on 04 Dec 2012
In reply to Milesy:

> The 2mm, 3.5mm titaniumm bits snapped in the drill without making a dent. The 5mm just seems to spin, and spin and spin and spin....... christ.

A center punch, sharp cobalt drill a few drops of oil and nice steady pressure from a drill press should see you through unless the Flys are seriously tough.

jk
Milesy - on 04 Dec 2012
How is a centre punch going to make a dent in such hard metal if titanium drill bits wont?

I only have a plain single speed corded drill (with hammer turned off).

I could only get the Titanium ones near me. I need to balance all this cost off with just selling the things and getting new axes. I have already wasted 30 quid on drill bits, and then when I price in the potentially wasted grip rests and petrol and hassle I would have been as well just getting the new axes.
andic - on 04 Dec 2012
In reply to Milesy:

The hardened steel of a decent punch will be harder than what your axes are made of and you need something to stop your bit running off esp if you are not going to use a pillar drill or stand
jkarran - on 04 Dec 2012
In reply to Milesy:

Spinning good drills against tough metal too fast without enough pressure or cooling just softens and blunts the drill. It can also work harden the spot you're drilling. You need to use a drill press.

The tip of the punch will be much harder than your axe handle.

jk
winhill - on 04 Dec 2012
In reply to Milesy:
> How is a centre punch going to make a dent in such hard metal if titanium drill bits wont?
>
> I only have a plain single speed corded drill (with hammer turned off).
>
> I could only get the Titanium ones near me. I need to balance all this cost off with just selling the things and getting new axes. I have already wasted 30 quid on drill bits, and then when I price in the potentially wasted grip rests and petrol and hassle I would have been as well just getting the new axes.

I've not tried drilling Flys but on other metals I've tried the big difference wasn't the bit or the drill (I used hand held) but getting some cutting oil. I would've got paste but couldn't find any so ending up going to machine mart where it was about a tenner for a big bottle of oil.

After that it went fine, nothing to do with the bit or the speed of the drill.

A decent centre punch will stop you slipping, especially once it's oily.
mkean - on 04 Dec 2012
In reply to Milesy:
The tips of the punches are seriously hard plus you are going to have a 2lb hammer behind it :-)
wupert on 04 Dec 2012
In reply to Milesy:

Just take it too a man at an engineering works, it will cost you a fiver at most,there's one on most industrial estates. Much cheaper than posh drill bits etc
DPaul - on 04 Dec 2012
In reply to Milesy: Did this with B&Q tungsten carbide bit(can't remember exact size,but cost under 10),dewalt corded drill and a vice-straightforward job.
Milesy - on 06 Dec 2012
My mates dad is actually a machinist so he done it for me today in his work. Job done. thanks everyone.

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