Drilling out pop rivets

I'm having difficulty drilling out pop rivets. Are they made or something that work hardens or something? Or have I just got naff drill bits? Or is a cheap cordless drill not up to the job?

Reply to
Doki
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The bit of steel that snaps is high carbon steel, the trick is to either use exactly the right size drill bit or very carefully a slightly too big one & stop when you've cut the flange and or reemove the centre popped bit by knocking it out with a small centre punch before drilling.

Reply to
Duncan Wood

Also, make sure the little buggers aren't just spinning merrily in the hole.

DAMHIKT.

Reply to
PC Paul

Sometimes the rivit spins with the drill bit. Holding the drill at an angle will mean it still cuts the rivit (even though it may still spin).

Reply to
Andrew Gabriel

Sometimes the remainder of the bit that snaps is left at various lengths, which makes for difficulties in properly penetrating the rivet with the drill. The other thing that can happen, fairly frequently in my experience, is that the drill bit may start the rivet turning in it's hole, necessitating pliers/ mole grips on the back, if it's accessible, or tears if it's not.

Reply to
Teddy K

The HCS mandrel is the least of your worries as you'll usually find it can be tapped through and out the other side of the (alloy) blind rivet, unles it is of the closed end type. If you are drilling pop rivets in your car I suggest using the right drill speed for an 'average' aluminium alloy, and make sure your drill is sharp.

If you are drilling rivets in a boat/yacht you'll find that they are likely to be made of Monel metal, similar to one of the popular Stainless steels. This will work harden as a result of the heat of drilling too fast. Start slow. Really slow, and just let it squeal and chatter. You might try using a cutting fluid or (Last resort) a squirty bottle full of water, just to keep drill and rivet cool. Mind the water if you are using a drill that plugs into the mains.... When you finish, then will be time to re-sharpen your drill.

A
Reply to
Adam H

tap out the centre, then drill. A sharp thin chisel is often the fastest, easiest method.

Reply to
Mrcheerful

There are two types of pop rivet.

The first one is called a 'break stem' and as suggested leaves part of the stem locked inside the rivet. The ball that swells the rivet is trapped inside the rivet

The second types is know as a break head and this lets the ball that sets the rivet fall out of the rivet.

Obviously, when you use a rivet in an enclosed blind area, you do not want bits of it ratting around after you pull and set them, so you chose a break stem type.

As others have said, it is possible for the rivet to revolve when trying to drill it out. just hold the driven twist dill at an angle of about 30 degrees from the direction of the rivet and you will be able to get the head of the rivet off. If the tail remains, just use a punch and it will fall out.

I have nearly 30 years experience of this.

HTH

Dave

Reply to
Dave

A sharp thin chisel is often

================================== I agree, I find this method works very well. A sharp tap with a hammer on an old (but sharp) wood chisel can be used to slice the top off the rivet.

If you've got space a very light touch with an angle grinder will also do the job, and the remains of the rivet can be tapped through the hole.

When I do use a drill, I find that a fairly big drill works best - about

3/8".

Cic.

Reply to
Cicero

It's not spinning around uselessly, thankfully. I suspect my problems are down to either crap drill bits or the stem still being in there.

Excellent.

Reply to
Doki

I'd agree completely with that. Usually ally rivets drill out easily, but if they are marine grade a cobalt drill will help no end.

Reply to
The Medway Handyman

Most are ally and drill out easily. However, the 'pip' that breaks off the shank is sometimes close to the head and that's hard steel. Which will stop the drill. Punch it out first with a shank.

Reply to
Dave Plowman (News)

I suspect a bad drill bit or the fact youre using a cheap cordless. A mains drill would be way quicker.

The other option not yet mentioned is to use wire cutters of the flush cutting type - these have no angle ground on one side and will cut flush. They can snip ali rivets off with one squeeeze.

Re the steel bit in the middle, apply a nail and give it a tap.

The last thing is that standard HSS twist drills dont work that good on ali, try a gold coloured coated bit instead.

Angle grinders are quick on rivets, but they do make a mess of the surrounding metal.

NT

Reply to
meow2222

First I've heard of this. ;-)

Reply to
Dave Plowman (News)

Sorry, but that is just plain nonsense.

A gold coloured bit usually means it is a HSS drill bit with a Titanium nitride coating, TiN, which gives it a harder surface finish than plain HSS.

Ally being a soft material is easily drilled using plain HSS bits. Even carbon steel drill bits have little trouble drilling ally. Certainly no problem drilling pop rivet material apart from the pins themselves.

Another point about TiN coated bits is that sharpening removes the TiN from the cutting edge. They are then no better than plain HHS bits.

IME as an engineer, a set of HSS drill bits is as good as any for drilling all the but the toughest material.

It also helps if you know how to resharpen them. Mike.

Reply to
Mike G

Me too and I have spent most of my working life in the aerospace industry teaching others to drill difficult metals.

Dave

Reply to
Dave

The only thing that might make a difference is that drills with a large included point angle for drilling alloys where often TiN coated & they're also quite good for drillin pop rivets out without snatching.

Reply to
Duncan Wood

No, it's true. gold coloured things work better.

Otherwise why would the goldy coloured car parts in Halfords be twice the price of the ordinary ones?

Answer me that, eh?

Reply to
PC Paul

Golds really corrosion resistant?

Reply to
Duncan Wood

Gold 'coloured'.

Reply to
PC Paul

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