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[grifter]

Hi what's the best drill bits anyone can recommend for drilling out threads. Is cobalt the name of the game for this?

[Andy B]

cobalt are harder drill, but if it's just AN Other bolt on your car, a reasonable HSS drill (not a set of 100 from the £ Shop  ) is good enough

[Kevin Wood]

Indeed. Remember, the harder it is, the worse it is to sort out if when it breaks off in the hole.

[omega2018]

bolt extractor/left handed drill bit, something like this www.ebay.co.uk/itm/311734242947

cobalt is the best for drilling any hardened steel but as mentioned more brittle so more likely to break

[Andy H]

Is it a bolt on an Omega?

[Broomies Mate]

Drilling is bit of an art.  You can't go in heavy handed, especially with hardened steel, or steel which has been hardened due to high temperatures.

Slow and steady.  Use less force than you would expect, let the bit do the work.

Start off small and work up.  It's easier to cut material away once a pilot has been drilled.


The amount of times I've seen 'mechanics' trying to drill out a 8mm threaded bolt with a 7mm drill bit in an air gun, leaning on the drill while it spins at 324348 gazillion RPM.  Just Dont Do It.

There really is no need to spend a fortune on drill-bits.  Even the cheapers end of the scale will perform just fine IF they are used correctly.

[grifter]

Is it a bolt on an Omega?

Nope, I'd been meaning to find out as it's something I come up against here and there.

[grifter]

Is it a bolt on an Omega?

Nope, I'd been meaning to find out as it's something I come up against here and there.

Usually give the drill tip a scoosh of oil now and again and don't lean on the drill permanently, let it off and on in short bursts.

[Viral_Jim]

Drilling is bit of an art.  You can't go in heavy handed, especially with hardened steel, or steel which has been hardened due to high temperatures.

Slow and steady.  Use less force than you would expect, let the bit do the work.

Start off small and work up.  It's easier to cut material away once a pilot has been drilled.


The amount of times I've seen 'mechanics' trying to drill out a 8mm threaded bolt with a 7mm drill bit in an air gun, leaning on the drill while it spins at 324348 gazillion RPM.  Just Dont Do It.

There really is no need to spend a fortune on drill-bits.  Even the cheapers end of the scale will perform just fine IF they are used correctly.

+1 to all of this. Top advice. I buy all my bits from toolstation and have never had a problem drilling out any bolts I've had to on cars. Usually do mine in 3-5 stages depending on the size of the bolt.

[Doctor Gollum]

Well that's summat learnt today... 

[Andy B]

Well that's summat learnt today... 

So have I 

...... some people buy their own drills 

[henryd]

Well that's summat learnt today... 

So have I 

...... some people buy their own drills 

Lol

[Andy B]

Well that's summat learnt today... 

So have I 

...... some people buy their own drills 

Lol

 

[omega2018]

the cobalt bits  have a split point and a 135 degree point angle compared to normal 118 degrees.  they require less pressure.  i would always use a cobalt on a bolt but they can snap if abused even a little.

[Broomies Mate]

the cobalt bits  have a split point and a 135 degree point angle compared to normal 118 degrees.  they require less pressure.  i would always use a cobalt on a bolt but they can snap if abused even a little.

Whats the forum term?  Dangle Berries or something.  A drill bit is a drill bit.  That's all you need to know.

Next we'll be having threads on buying Chrome Vandium spanners.