Help with drilling chrome ???

[WildBill2566]

I need to drill two 4mm holes in the vertical support brackets on my windshield, to fit a TomTom Rider. I have tried every drill bit I have, and man this stuff is hard. I tried starting with a 1.5mm bit, but even this wont bite.

Anyone got any ideas?

Thanks in advance for any replies

[Spice]

Its just the hard chrome that your drill bit is struggling with penetrating initially.
mark and give it a hard and deep centre punch hole, and using a sharp steel
ideally a new drill bit and using some oil any old oil will do. as a coolant.
using a low speed and applying some pressure. it should start and then continue, having broken that initial hard chrome plate. harley chrome although thin is very hard,
failing that it aint chrome its Cryptonite
good luck and let us know how you get on
Spicey

[Roger]

Chromium is bloody hard - about 8.5 on the MOHS scale. Tool steel is usually about 7.5. Try making a pilot hole with a Dremel (if you have one) using either a diamond bit or a very small carbide point to break the surface.

[Stuarty]

Why not get a wee bracket made up and fit it to the bars?

Get a map ;)

[WildBill2566]

Ok gave up with plan A, dont know what it is made of but even after using a diamond bit and the Dremmel the steel below is like diamond. Fitted a bracket to the screen just below the rail, looks pretty good.

and yes I've done the map thing, but I've found something better. The SatNav in the car is a blessing on foreign soil, and I fully expect the one on the bike to be as useful.