What hole saw for deck lights?

[Sayuru]

Hey there, I'm a very very newbie DIYer who recently fell in love with all these tools and stuff. I'm doing a small treated pine deck in my front yard and I want to install deck lights 

Deck Lights Kit This is the kit I have selected. It comes with 40mm lights. My treated pine decking slats are 90mm, so I'm guessing the size is fine (?)

But my big question is, how do I find a tool to cut holes for these lights? I couldn't find a spade bit or a hole saw of diameter 40-42mm. The closest sizes were 38 and 44. 

Any suggestions?

Any help and guidance is highly appreciated. 

Thanks.

[MitchellMc]

Welcome to the Bunnings Workshop community @Sayuru. It's sensational to have you join us, and many thanks for your question about installing deck lights.

So glad to hear you've caught the D.I.Y. bug; it opens up a whole world of possibilities.

Those lights will be fine for your 90mm decking. 

Although they call them 40mm lights, that's the outside diameter of the stainless front flange. The rear insert that goes through the decking board is actually smaller. According to the instructions, it requires a 30mm hole in the decking board, and this IRWIN 30mm Blue Groove Spade Bit would suit. You could also use the 32mm hole saw in this kit. However, my preference would be to go with the spade bit.

Please let me know if you have any questions.

Mitchell