How to drill holes in ABS plastic without splintering?

I used standard jobber drill bits to drill a line of holes in an ABS plastic enclosure.

Final dimeter is to be 10mm. I centre punched then pilot drilled 3mm (rightmost hole) at a slow speed, then went straight to final size, and the plastic snatched.

Clearly my technique is wrong. Please give me clear instructions on how to get it correct on the replacement! Thanks in advance.

Other more capable people will come in after me

Nice sharp drill (wood drill?)

sandwich between 2 bits of wood?

Some good advice in this video.

Ed.

Edited By Ed Duffner on 04/08/2018 03:37:37

Edited By Ed Duffner on 04/08/2018 03:37:55

Yes sir, that's good information!

Pete

I use a step drill as it only has one cutting edge it wont't dig in

Having support material above and below the part. Negative or dulled off a drill bit like the video is good for plastics. Also withplastic , not too hi a rpm. Otherwise it will want to melt the material. Same for a lot of other plastics.

Neil

As NL. Alternatively use a slot mill.

Step drill as they have almost zero helix and as they take small cuts per step won't rip into the work

Or a lip & spur bit as used for wood though watch the exist side with that.

A wood drill, or a metal drill reground like a wood drill so it has two cutting tips and a tit in the middle. These work well for thin sheetmetal too.

You need to use one of those tapered drills for cutting holes in very thin plate or ,perhaps a countersink drill

with many cutting edges ( don't let it get hot ! ).

Are you sure it's ABS? I've drilled hundreds of holes in plastic boxes, mostly for work, and never seen it chip like that.

I use standard 4-facet Dormer A002 drills. Like in brass they'll snatch if given a chance so you have to clamp the work properly. The clamping doesn't need to be tight, but it needs to be in the right place to prevent the work from lifting. I don't bother marking out and centre popping, just use the DRO on the mill. For a 10mm hole I'd start with a pilot hole around 6-7mm and finish off with 10mm.

Incidentally stoning the edges of the drill as shown in the video has never worked for me. You just end up badgering a perfectly good drill. For brass and bronze I've got a small selection of slow spiral drills for bulk removal of material. If the width of cut is small for subsequent enlargement the drills don't have much of a tendency to snatch.

Andrew

Are you sure the material is ABS?

I have worked with ABS for may years and have never found any difficulty in drilling holes in it using normal jobbers drills other than a bit of "rag" sometimes on the exit side. The material sown it the photo looks as if it has a lot of filler in it.

Eric

This is what I use for plastic and brass one is a slow spiral and one has definite flat to prevent grabbing. I keep them just for that use.

David

Clamp it down, close to the holes.

Step drills do work well,

Defo ABS plastic apparently from datasheet. To elaborate: I had it clamped in the bench vice with a softwood block behind supporting.

The work definitely didn't lift, it's like the bit (a normal 118 deg jobber) started tearing into the plastic due to too quick material removal, leaving the unsightly ragged edge.

Another vote for a step drill, never had a problem with drilling Perspex at work with them.

Clamp it down firmly on a sacrificial wood surface and use a hole saw with the finest teeth you can find.

Could well be ABS - but with high percentage of degraded regrind, used as a way to dispose of ("recycle" ) flashing and sweepings. Every time the material is melted in the moulding machine, it degrades but many moulding companies like to minimise the amount of stuff they have to dispose of, so they feed it back into the mincer.

I have some of those "Hippo" type builder's buckets from Aldi that are nothing like as tough as the real thing but that also includes the price which is bargain buckets in comparison. I expect they have recycled everything but the kitchen sink into those.

Murray

Edited By Muzzer on 04/08/2018 17:49:57

Hmmm, given your recent travails with kitchen sinks it may well have the kitchen sink in it.

Andrew

I always drill through plastic into wood. Pallet timber is adequate.

Regards,

Richard.