[JSMC]

i have drilled the floor of van and located all holes for tank to be situated. I have also placed 4 rods of metal through chassis for steel bolts to insert into. I have spreader plates cut to size and primered and painted.
all i need to do is drill 13mm holes through 5 mm plate and thats it!!! Is it feck. i bought a 13mm blacksmith drill bit and cutting paste and thought here we go. i got one hole drilled and it seems drill bit is now useless.

other weekend my bosch multipurpose drill bit also got knackered.

what the hell do i need to cut holes in this steel plate.

[EZclean]

A-Team 

[JSMC]

thinking that myself mate. god knows what now.

[john tomkins]

You're not trying to go straight through with the 13mm drill are you?
Start with a pilot hole and work up to the 13mm.

[mingram123]

 Use a cobalt drill at slow speed .
 
 Mike.

[NWH]

Diamond tipped drill bits is what you need.

[JSMC]

i had a 12mm hole and wanted it out to 13mm so i used the 13mm drill and it was ok.

next hole was utter crap and drill is now blunt. i tried a 6mm hole there and then the 13mm drill utter pants would best describe this drill bit.
hope to have it sharpened by weekend

[steve bell]

Hmmm... I know it can be frustrating. Best advice is make sure the drill is turning pretty slow. The speed of the drill is what has caused you the problem.
Steel has a specific cutting speed, meaning the smaller the hole the faster you can get away with. At 13mm diameter I'd suggest around 50 to 75 rpm if you can get the drill as slow as that.
Don't be in a rush and press too hard either. The drill will chew through it nicely if you treat it right.

Sorry if all of this is gobbledigook. I am actually an engineer by trade, windows is something I've fallen into.
 

[JSMC]

the drill is now blunt i reckon. i have drill set to lowest speed but no use now

[steve bell]

Was going to offer to pop over, then I realised your miles away from me here in sunny yorkshire. Sorry, Guess a new drill bit is the way forward?
Either that or a grinding wheel so you can sharpen your old one?

[matt]

for future reference for other

start off with a small hole and work up in a few mm jumps

i just use water from a fairy bottle to cool the bit

[ftp]

Or pure water which of course will melt through it. 

[Bazzy1999]

As said.. start with a small hole 5mm or 6mm on high speed then 13mm slow speed and keep it cool with water...
You can resharpen the drill bit if you have a small bench grinder.

Bazz....