Drilling 5mm pilot hole x150mm deep through oak sleepers - drill bit recommendations please!

[Deleted member 174758]

I would tend to agree. Counterbore the top one first (maybe 12mm, but also needs to be big enough to get the socket in there as well), then clearance drill it (8mm, standard 235mm auger bit) through the first piece of timber. It's only the second piece of timber where you need the pilot bit, and at 50 to 60mm that could be a cheap 5mm or 6mm brad point twist drill - you'd need to test on a piece of scrap if you get enough holding poser with the 6mm. If you clamp the two pieces together and drill through the first to full depth it will leave a mark on the second one that you can use to drill the pilot hole. Make sure that you lubricate the screw with either soft soap or wax polish when you install it and it will go in a bit easier

 

[Temmy]

@foxhole @JobAndKnock Thanks both for your advice. Will be tackling this in a few days.

 

[Temmy]

What an absolute dream. Just to say this is working out great. I'm using 25mm oak dowels to plug things after fixing, and bashing those in and sawing them level with the top of the sleepers is strangely super satisfying.

Thank you for your help!

 

[Deleted member 174758]

Glad you got it sorted. Thank you for posting the end result. We don't always hear