I saw these on tv shopping, says metals fine, has anyone tried them on hard metal ?
www.drillalldrillbits.com/page3.htm
www.drillalldrillbits.com/page3.htm
Diamond Tipped Drill Bits - Uk tv shopping
- Thread starter petrochemicals
- Start date
thanks for that, I was thinking of getting some as Bosch do something similar, but if theyre rubbisd I'll not bother, it will have to be a grinding tip then.
www.screwfix.com/p/bosch-multipurpose-drill-bit-7-x-100mm/78311
www.screwfix.com/p/bosch-multipurpose-drill-bit-7-x-100mm/78311
Cobalt drill bits are the way top go for drilling harder metals. 
The bosch ones do look handy but I'd rather have the right drill bit for the right material. Masonry and wood bits aren't expensive, the cobalts are but can be sharpened again.
The bosch ones do look handy but I'd rather have the right drill bit for the right material. Masonry and wood bits aren't expensive, the cobalts are but can be sharpened again.
Diamond is not a material that I'd choose for something which might experience high temperatures as when all's done it's just carbon, and it will burn just like coal will burn. The description on the page linked is completely unconvincing anyway.
Generally I'd avoid diamond tipped tools except for special applications. When I was doing a lot (miles) of scribing steel plate prior to gas cutting I tried diamond tipped scribes. The tips kept falling off and getting lost and I went back to the old faithful tungsten carbide. They just break.
Some of the cheap drills out there are real rubbish, especially those made in China. Don't get me wrong, China knows how to make good stuff, but it will also sell you complete tat if you let it and in my experience more tat than good stuff leaves China.
On the other hand I bought a set of cheap drills (not diamond) from Aldi a couple of years ago (nothing like those linked in the OP) and I was so impressed I bought another two sets the next time they did the offer. The package claims they're made in Germany, which given the performance of the drill I can well believe.
I've never seen them anywhere else, here are photos of the pack:
http://www.jubileegroup.co.uk/JOS/misc/dscf4032a.jpg
http://www.jubileegroup.co.uk/JOS/misc/dscf4034a.jpg
Generally I'd avoid diamond tipped tools except for special applications. When I was doing a lot (miles) of scribing steel plate prior to gas cutting I tried diamond tipped scribes. The tips kept falling off and getting lost and I went back to the old faithful tungsten carbide. They just break.
Some of the cheap drills out there are real rubbish, especially those made in China. Don't get me wrong, China knows how to make good stuff, but it will also sell you complete tat if you let it and in my experience more tat than good stuff leaves China.
On the other hand I bought a set of cheap drills (not diamond) from Aldi a couple of years ago (nothing like those linked in the OP) and I was so impressed I bought another two sets the next time they did the offer. The package claims they're made in Germany, which given the performance of the drill I can well believe.
I've never seen them anywhere else, here are photos of the pack:
http://www.jubileegroup.co.uk/JOS/misc/dscf4032a.jpg
http://www.jubileegroup.co.uk/JOS/misc/dscf4034a.jpg
well from what I've read with hard hard stuff that will not deform enough for conventional drilling, there seems to be 3 ways to go
1) to grind/wear away
2) hammer action (maisonry)
3) or to soften the work piece for conventional drilling to bite into it. one way of drilling files is to heat em up and use a tungsten bit on them
I know what your saying with good cobalt and hss bits, but if the metal will not give the drill won't bite. Theory on the masonary bit is it is a grinding bit. Cheap and long lasting. I'll buy one and report back because I'll end up having to anyway. If it is diamond I will try and keep it cool.
1) to grind/wear away
2) hammer action (maisonry)
3) or to soften the work piece for conventional drilling to bite into it. one way of drilling files is to heat em up and use a tungsten bit on them
I know what your saying with good cobalt and hss bits, but if the metal will not give the drill won't bite. Theory on the masonary bit is it is a grinding bit. Cheap and long lasting. I'll buy one and report back because I'll end up having to anyway. If it is diamond I will try and keep it cool.
Whittler Kev
Bushcrafter (boy, I've got a lot to say!)
Can't get better than Dorma. Easy to sharpen again even if you snap one. Most shows have sets for sale that will drill files, hammers, brake discs, etc with a "lifetime guarantee" if you break or blunt one of them - Yeah right! All of the cheapies will as well if you get the metal your going to drill red hot and let it cool naturally. That's how we metal bashers make strikers etc 
Cobalt drills are good but still blunt.
False economy buying a set as you will probably only ever use a few of the sizes. I get the sizes I want from EBay or UKdrills in job lots of 5ish
Cobalt drills are good but still blunt.
False economy buying a set as you will probably only ever use a few of the sizes. I get the sizes I want from EBay or UKdrills in job lots of 5ish
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