Drill bits

[Toneyz]

Is it me or when you have used a drill bit (especially metal) they are blunt same with hole cutters.

 

[Toneyz]

There's quite a science to drilling a hole in metal and getting maximum drill life and efficient drilling.
Some materials require lubricant to drill them, cutting oil for steel, wd40 for aluminium whereas other materials such as cast iron are self lubricating due to the high carbon content.
Running the drill too fast will wreck it, generally the bigger the diameter the slower the drill should be.
Drills work their best at specific cutting rates, cutting too little material at once can blunt them so a lack of pressure on the drill can kill the drill bits, but too much pressure can kill them too.

Some good advice there Dave thanks.

 

[Timbo]

Just bought 2 sets of Metabo 1 - 13mm, 25 piece, for £5.99 + VAT each. Disposable at that price.
toolstoreuk.co.uk

 

[-Matt]

I use steel conduit cutting compound on the hole saw when drilling steel.
Massively increases hole saw life.