Landyfox

Well-Known Member
As most know, I've fitted one of the fabulous rear crossmebers made by Clive! Wow, what a bit of kit, I've not seen anything Land Rover related as well built. However.... in that lies the problem lol! I'm trying to fit new mud guard brackets to X Member but each drill bit I'm using is hardly marking the X Member and burning it self out within seconds.

I'm using HSS DeWalt bits at low speed with plenty cutting oil.

Can someone possibly suggest an appropriate bit!
 
I drilled mine with no issues, small drills like to go fast.
My favourite start size is 4mm, nothing special and certainly no cutting oil and a good bit of pressure as well.
Remember to put a washer or nut between the mudflap bracket and the x member bottom face to stop corrosion starting.

Not taking the **** but just check drill is in forward gear, weve all done it!
 
cobalt 2mm then whatever size you need ie 6mm

+1. I've used Cobalt drills for years, and they were expensive not that long ago - now 5% cobalt are almost cheap enough to throw away. IME, the Silverline ones are good enough for any hand held application - but for machine drilling I use something a bit better, preferably Osborne / Dormer.

IMHO, always use cutting oil - the tectane stuff from toolstation is good for hand held drilling!
 
As most know, I've fitted one of the fabulous rear crossmebers made by Clive! Wow, what a bit of kit, I've not seen anything Land Rover related as well built. However.... in that lies the problem lol! I'm trying to fit new mud guard brackets to X Member but each drill bit I'm using is hardly marking the X Member and burning it self out within seconds.

I'm using HSS DeWalt bits at low speed with plenty cutting oil.

Can someone possibly suggest an appropriate bit!
Don't take this the wrong way but a friend of mine had the same thing drilling steel and when I looked the battery drill was set to reverse, the drills were just rubbing, a HSS drill should be well able to drill mild steel, which should be the case here if the section has been folded to make the cross member. Especially If you are using a cutting fluid then they should be fine.
 
As most know, I've fitted one of the fabulous rear crossmebers made by Clive! Wow, what a bit of kit, I've not seen anything Land Rover related as well built. However.... in that lies the problem lol! I'm trying to fit new mud guard brackets to X Member but each drill bit I'm using is hardly marking the X Member and burning it self out within seconds.

I'm using HSS DeWalt bits at low speed with plenty cutting oil.

Can someone possibly suggest an appropriate bit!

Are you drilling slowly.... ? If you full blast you will never go through, go as slow as you can and make sure you see metal coming off if its not cutting in you are
a. going too fast
b. drill is knackered
 
I'm using HSS DeWalt bits at low speed with plenty cutting oil.

Therein lies your problem - HSS! - HIGH SPEED STEEL! They are made from tool steel and are much more resistance to heat, run it fast with moderate pressure.

All drill bit types depend on different usage techniques. Drills are not just bits of metal that cut material away. Different materials (ali, copper, steel, iron) need different types of drill bit; the point, helix and relief angle needs to be different for different materials. Which is why often people find when they try to drill grey cast iron with a 'good drill bit', not a lot seems to happen, this is because they need a lower point angle of about 90°.

Ever wondered why drilling on a pillar drill cuts so much better, it's because you can apply a constant pressure and with the drill spinning at the correct speed you get a great first cut then the metal will chip or spiral off well - drills don't actually cut once they are in the hole running, they should lift the material away as the chip is lifted up into the flute.
 
Dormer 4 mm C1150 drills are ideal for pilots in metal up to around 3/16" thick. Low speed medium pressure will cut almost any material. You should not need cutting oil on chassis plate. It actually hampers the bite.
 
Therein lies your problem - HSS! - HIGH SPEED STEEL! They are made from tool steel and are much more resistance to heat, run it fast with moderate pressure.

All drill bit types depend on different usage techniques. Drills are not just bits of metal that cut material away. Different materials (ali, copper, steel, iron) need different types of drill bit; the point, helix and relief angle needs to be different for different materials. Which is why often people find when they try to drill grey cast iron with a 'good drill bit', not a lot seems to happen, this is because they need a lower point angle of about 90°.

Ever wondered why drilling on a pillar drill cuts so much better, it's because you can apply a constant pressure and with the drill spinning at the correct speed you get a great first cut then the metal will chip or spiral off well - drills don't actually cut once they are in the hole running, they should lift the material away as the chip is lifted up into the flute.
Bollocks... HSS allows you to cut faster than normal cobalt steel...... "run it fast" is never advised.
 
Bollocks... HSS allows you to cut faster than normal cobalt steel...... "run it fast" is never advised.

Cobalt steel drills are superior to HSS drills. Carbide drills are superior to both. Use Dormer drills if you can. Low to medium speed and moderate pressure is the way to drill metal depending on it's hardness. He wants to try drilling normalised tool steel at high speed and see what happens. ;)
 
All getting a bit involved, remember this is sheet steel which has been folded so it will be a fairly ductile mild steel, should drill easily with an HSS drill.
Maybe it is a bit blunt.
 
All getting a bit involved, remember this is sheet steel which has been folded so it will be a fairly ductile mild steel, should drill easily with an HSS drill.
Maybe it is a bit blunt.

I would suggest if you can't cut, what as you say is more than likely mild steel with an HSS drill bit, a bit blunt is a gross understatement. :D:D
 
It's a few holes in a bit of galv, not disagreeing with anything above but a decent brand of HSS should do the job easily. The quality of Dewalt accessories is extremely disappointing imo but even so they should cope.

Slow speed, steady pressure is the key. If they're burning out they're blunt or you're way too fast.
 
Bollocks... HSS allows you to cut faster than normal cobalt steel...... "run it fast" is never advised.

Clearly you know little about machining, turning and drilling etc. Also your comment further shows your total lack of understanding of this subject; those who know the difference between drill bit materials will also know what I am talking about regarding your comment. Go and do some research!
 
Cobalt steel drills are superior to HSS drills. Carbide drills are superior to both. Use Dormer drills if you can. Low to medium speed and moderate pressure is the way to drill metal depending on it's hardness. He wants to try drilling normalised tool steel at high speed and see what happens. ;)
I meant carbon... sorry Cobalt came from me reading the other thread...
 
It's a few holes in a bit of galv, not disagreeing with anything above but a decent brand of HSS should do the job easily. The quality of Dewalt accessories is extremely disappointing imo but even so they should cope.

Slow speed, steady pressure is the key. If they're burning out they're blunt or you're way too fast.
Its funny you say that, I have a few Dewalt items and I was thinking they were the better end of the market when purchased but they disappointed me.
 
Thanks everyone I appreciate you advice!!!

Yeah definitely drilling the correct way, although after reading your post I did have to double check... self doubt kicked in lol... but it's definitely set correctly. I have my speed setting on 4 and would've thought that was low enough.

I must admit, I must agree with BB. I'm not impressed with the Dewalt bits, I purchased them specifically for this job. I'm also using the battery powered Dewalt drill and sufficiently charged. Can anyone suggest an alternative make of bit as I really have no confidence in them.
 
Thanks everyone I appreciate you advice!!!

Yeah definitely drilling the correct way, although after reading your post I did have to double check... self doubt kicked in lol... but it's definitely set correctly. I have my speed setting on 4 and would've thought that was low enough.

I must admit, I must agree with BB. I'm not impressed with the Dewalt bits, I purchased them specifically for this job. I'm also using the battery powered Dewalt drill and sufficiently charged. Can anyone suggest an alternative make of bit as I really have no confidence in them.
Felt a bit cheeky suggesting it, but some drills are easily reversed by accident, and you know what they say if you haven't made a mistake its because you haven't made anything.
at the risk of starting things off again, easy to work out the correct drilling speed of HSS drills the cutting speed should be 80 - 100 ft per min max
So look at the diameter of the drill bit, multiply by 3.142 ( 3 will do) multiply by the RPM of the drill machine and that would give the speed in MM/ min, divide that by 305 and you will have ft per min.
 

Similar threads