Drilling Technique For Metals

[GLPoomobile 958]

I know this will be child's play for some of you, but I'm acutely aware that I totally suck when it comes to drilling anything metal. So I'm after some tips.

 

As an example, I recently had to drill 4 rivets out of my V70's door skin, which hold the speaker basket in place. You'd think rivets would be easy, well I did anyway. But noooo, these were some sort of triple-hard-bastard rivets. I was using brand new HSS bits, kept swapping sizes to see what worked best, using a slow speed and some WD40 for lubrication and to keep the heat down, but what a fight they put up! I've still got the passenger door to do.

 

I realise different metals probably call for slightly different tactics, but what are the basic rules I should be following for stuff like SS and hardened steels?

[DamirGTI 323]

I use carbide/tungsten burrs for poping off rivets , i have various shapes and sizes which i usually use for head porting jobs ..

 

The ball type burr is the one with wich i just press on the rivet and drill it down untyl it flattens off flush with the panel skin then the rivet head just pops off and the panel skins can then be separated .

 

 

D

Edited June 3, 2017 by DamirGTI

[toolie72 67 1 Cars]

We drill a lot of rivets (when we're hiding the scrap metal from boss)

Always found dormer or presto to be good

Some hss bits like makita etc are utter pish

[Tom Fenton 1,524]

Anything that's truly hardened forget it, you likely won't touch it with a drill bit and will usually need to grind it.

 

Decent drills help a lot. Slow speed is good but don't be afraid to push into the job. If the drill skids round on the surface not cutting then you build heat up, this can then make whatever it is (in the case of carbon steels anyway) progressively harder and harder.

[ciarandeery1 22]

Cutting paste like trefolex on the drill bit will definitely help keep the heat down.

 

Good sharp drill bits also are your friend

[petert 549]

If the rivet is SS it maybe work hardening as you're drilling. The key is to use lots of feed, low RPM with a sharp drill.

[Kambo 9]

This is not just for rivets but for general screw heads/bolts etc

 

Your basically doing what you need to be doing apart from the drill bit. You've basically done it the harder way. Carbide/tungsten tip will make the difference

 

If you have one use a punch to get started and use the thinnest drill size you have, that first pilot hole is the hardest, keep it straight or it will snap, keep a slow speed and hard pressure, keep to one slow speed and if you see shavings/swarf coming off your on

 

If not, vary the speed but keep the pressure on and you'll find the ideal speed when shavings start spiralling off

 

Then start going up drill sizes to required hole size (for removal tools etc)

 

Just taken off four wheel locking bolts

[Bobbafett 49 2 Cars]

Get some Bosch Multi-Construction bits. I use them at work for drilling everything and they are very very resilient and good at drilling stuff.