corrado vr6
|
| posted on 15/11/11 at 11:02 PM |
|
|
drill bits
Hi there, need to drill out some bolts but whenever i try and do this my drill bits never seem upto the job, and advice as to which set to look out
for i normally go for hss bits but they just dont seem to last! any suggestions? Many thanks in advance, Greg
http://r1indy7.wordpress.com/
|
|
|
|
|
daviep
|
| posted on 15/11/11 at 11:11 PM |
|
|
Buy good quality such as dormer or presto.
Cobalt are harder and will handle higher temps better but are more expensive.
Use the correct speed and a cutting lubricant, rule of thumb for speed is that you should just about be able to see the individual flutes.
Davie
“A truly great library contains something in it to offend everyone.”
|
|
|
madteg
|
| posted on 15/11/11 at 11:12 PM |
|
|
Cobalt but dear
|
|
|
MakeEverything
|
| posted on 15/11/11 at 11:15 PM |
|
|
Last set of 12 cobalt bits I bought was about £30. They do last if you look after them though.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
|
|
|
blakep82
|
| posted on 15/11/11 at 11:17 PM |
|
|
i like the bosch(?) Bullet ones. i got a 10mm one years ago, drills through 5mm steel plate in seconds.
not sure if they're really suited to drilling bolts out though, due to the shape of the tip, but worth a look anyway
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
|
|
|
daviep
|
| posted on 15/11/11 at 11:24 PM |
|
|
quote:
Originally posted by MakeEverything
Last set of 12 cobalt bits I bought was about £30. They do last if you look after them though.
The last set I bought cost me about £120.....they last well but it's heart breaking when you break one 
“A truly great library contains something in it to offend everyone.”
|
|
|
Autosri
|
| posted on 15/11/11 at 11:50 PM |
|
|
try using some wd40 it will keep the bit cooler so should last longer
|
|
|
RickRick
|
| posted on 16/11/11 at 07:10 AM |
|
|
If you can find them C1150 drills are good for drilling bolts, they only have a short flute so don't bent at all, and are really hard. like
this https://www.bolt.com.au/32mm-hss-c1150-sheet-metal-drill-p-81476.html
|
|
|
cliftyhanger
|
| posted on 16/11/11 at 08:04 AM |
|
|
Normal hss stuff isn't that great, def need decent brands or cobalt.
A mate works for Irwin, and nabbed a set of their drills. Absolutely brilliant, but not cheap. I guess like so many things quality costs. Or make
friends in the right places
|
|
|
Peteff
|
| posted on 16/11/11 at 09:52 AM |
|
|
It also depends on the bolts you want to drill out, If you can flatten the top and centre punch 8.8 you will probably have no problem but a jagged top
will push the drill to one side no matter what it is made of and harder drills are almost always more brittle. If you are drilling 10.9 or 12.9 you
will break anything occasionally.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
|
|
|
ashg
|
| posted on 16/11/11 at 10:52 AM |
|
|
i only use dorma now as cheep ones are a false economy. i have got some rather nifty cutting gunk that you dip the drill bit into before you start
drilling. easily doubles the life of the drill bit and stops it getting hot.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
|
|
|
Confused but excited.
|
| posted on 16/11/11 at 11:32 AM |
|
|
The fact that they are HSS doesn't mean that they have been heat treated properly as you will find with all cheapo bits.
As well as the Dormer, presto ones I have found the DeWalt 'Extreme 2' series to be good value for money.
Tell them about the bent treacle edges!
|
|
|
NigeEss
|
| posted on 16/11/11 at 11:40 AM |
|
|
quote:
Originally posted by RickRick
If you can find them C1150 drills are good for drilling bolts, they only have a short flute so don't bent at all, and are really hard. like
this https://www.bolt.com.au/32mm-hss-c1150-sheet-metal-drill-p-81476.html
I bought some like those, they were sold as drills specifically for stainless steel.
Time is an illusion. Lunchtime doubly so.................Douglas Adams.
|
|
|
rusty nuts
|
| posted on 16/11/11 at 07:55 PM |
|
|
Another vote for cobolt bits and cutting fluid. If the bolts have sheared it may be possible to weld a nut onto the shank, the heat often helps to
shift them
|
|
|
corrado vr6
|
| posted on 16/11/11 at 08:23 PM |
|
|
Thanks for replies guys looks like ill be spending some money then!
I have tried welding a nut on but it just keeps shearing, oh and incase anyones interested its bolts on a mini subframe that im having trouble with
Thanks again
http://r1indy7.wordpress.com/
|
|
|
.jpg)
