Drill Bits & Polycarbonate

[Mark-J]

Hi all,

I was hoping someone might be able to help me.

I'm looking for drill bits that will go through 4mm thick polycarbonate.

Ideally, I am looking for a 25mm drill bit and a suitable sized drill bit for a 5mm screw (I think they are 5mm screws).

The plan is to attach the 4mm polycarbonate to the bottom of a Stanley No. 71 hand router in order to extend the No. 71's underside surface. In effect, this extended underside surface will make it easier for me to work on the large tenons I'm making.

The 25mm drill bit will be used for a clearance hole, to allow the No. 71's cutting blade to poke through.

However, I need to make holes for two screws that will do the actual attaching of the polycarbonate to the underside of the No 71, but I am not sure which size screws to use.

I'm quite new to all of this so any advice would be much appreciated.

To summarise:

> I need a 25mm drill bit (not sure they even make them that size) that will go through the polycarbonate sheet.
> What sized screws for attaching the polycarbonate to the underside of the No. 71.

Here is a picture of the Stanley No 71 for reference. The white extended part represents the polycarbonate sheet.



Thanks all.

[Rorschach]

Can't help on the screw size, I don't have a stanley router. For the 25mm hole though I would reccomend either chain drilling and then filing to shape (if you want to be cheap) or buy a 25mm hole saw. Don't try with a forstner, it will shatter the polycarbonate.

[Bob225]

I would go with some phenolic ply over poly carb

pilot drill and step drill the 25mm hole

[Cannyfixit]

Aldi do a hole saw set,cheaper than buying a individual one
https://www.aldi.co.uk/workzone-carbide ... WEQAvD_BwE

[Job and Knock]

Polycarbonate can also be cut with a jigsaw and a wavy set metal cutting blade. All you need is a starter hole which can be drilled with an appropriate size of twist drill

[Nos]

Drill at a slow speed, at high speed the friction will melt though the poly instead of drilling through, dont ask how I know

[Mark-J]

Thanks all very much for the advice

Much appreciated.

[ayjay]

What's wrong with a handsaw for cutting tenons?

A tenon saw for small stuff or a rip saw (or a sharp panel saw, as not many people have a rip saw) if the tenons are too deep for a tenon saw.