Bench dog holes

[Rolf Safferthal]

Hello,

working on my workbench project I stumbled over the dimensions of round bench dogs - 3/4 inch. Quite an unusual size for a metric person like me, but converted to metric this is 19.05 mm.

Getting a Forstner drill bit for 3/4 '' might be difficult in Germany, but 19 mm drill bits are readily available. My question: how much tolerance in diameter do the round bench dogs have? Is it possible to insert them in such a slightly smaller bore? To enlarge the holes might be difficult in a top with a thickness of 2 5/8 ''.

Rolf

[Dave Falkenstein]

Perhaps this will help - 3/4 inch bench dogs and clamps fit into the Festool Multifunction Table (MFT), which has holes that I am sure are drilled with a metric drill, since Festool products are made in Germany. I think the MFT holes are 20 mm, but I am not positive. Maybe someone else can confirm the dimension???

[Frank Chaffee]

Confirm Festool MFT round holes @ 20 mm.

Frank

[Keith Hooks]

I think drilling a 20 MM diameter hole would give you the perfect amount of "play" in the fit, since you don't want the bench dog to fit too tight. The extra space will insure that it doesn't get stuck.

I'd recommend trying it out on some scrap. Drill the hole and see how you like the fit.

[Rolf Safferthal]

Thanks for the quick answers!

If 20 mm is right then it is easy.:) Yes I also thought that a little bit wider might prevent jamming of the dogs in case the wood shrinks a bit.

Thanks again for the advice.

Rolf