Trend Fostner bit

[MikeJhn]

How many 35mm holes should I be able to drill 13mm deep into 25mm MDF with the Trend bit before its so blunt I have to sharpen it?

Mike

 

[ED65]

What day of the week do you plan to drill the holes?

:mrgreen:

Seriously though, what speed does your drill run at? How hot a bit gets in use has a lot to do with how quickly it'll blunt.

 

[MikeJhn]

Any day that has an "a" in it. #-o

Thanks for the reply, the bit in question is the Trend T420/35 Hinge Sinker, so not a Forstner bit per see, the recommended speed is 1000 to 3000rpm, I used it at 1290rpm on my pillar drill and it lasted about five holes before it started to show signs of needing some attention, since posting this I have found this old thread: best-forstner-bit-for-mdf-t65861.html which recommends the Wealdon tools Hinge boring bit: https://www.wealdentool.com/cgi-bin/sh0 ... ml#aT1835A I have ordered one, but heaven knows when it will get to my workshop in France, will report back when it does and what its like.

Mike

 

[MikeJhn]

The Wealdon bit arrived today at my place in France, good service I call that, it was too hot to work today (over 40 degs) so spent it in the pool, even that was 32 degs, will try to get around to using it tomorrow to see how good it is. :twisted: :twisted:

Mike :twisted:

 

[MikeJhn]

Used the Wealdon bit in anger yesterday, once the correct speed was selected it just eat through the MDF without any trouble, it needed a much slower speed than I anticipated, but much better and a cleaner cut than the fostner or Trend.

Mike