Modular polo mallet head design

Rich, see my earlier post.

So if anyone is interested, I did a bit of experimentation with a Perro pole at Leyland today.

Anything between an M4 and an M8 fits down the shaft from the top, but not from the bottom (when it's not cut).

An M4 nut sits about 5cm from the bottom, roughly where the notch is.
An M5 nut sits about 8cm from the bottom, about 3cm above the notch.
An M6 nut sits about 15cm from the bottom, so well above the notch.

Leyland do 1m rods in all 3 sizes, for about £1.

I'm went with M6, as any lower and you would have to to cut around, or below the notch, and I imagine that's a weak spot.

For long M6 countersunk bolts I had to go to Clerkenwell Screws, they had them up to 100mm in length.