Drilling,...then routing...newbie question.

[fanlee]

Hi.

Is a 'Forstner' drill bit the same as a 'spade' drill bit? I've seen Forstner used on o'seas pages & my local Mitre 10 guy seems to think it's the same as a spade bit.

Could someone confirm this please?

If they're different where can I easily buy a set of Forstner bits?

Thanks for your time.

[jchappo]

Hi.

Is a 'Forstner' drill bit the same as a 'spade' drill bit? I've seen Forstner used on o'seas pages & my local Mitre 10 guy seems to think it's the same as a spade bit.

Could someone confirm this please?

If they're different where can I easily buy a set of Forstner bits?

Thanks for your time.

Forstner drill bits are not the same as spade bits.
They drill very clean holes, and can drill off-centre.

Try Carbatec, they sell sets of 16 for $49

John

[bsrlee]

Spade bits are definitely NOT the same as Forstner bits. Spade bits drill rough holes for rough jobs - thye are OK for drilling wire holes in wall studs for instance - they are flat with a central skipe to centre them, and in better examples have 2 spurs on the outer edges to reduce splintering.

Forstner bits, and their close relative, saw-tooth bits, drill neat holes. They have a circular body on the end of a reduced shaft, the edge of the circular body has a sharp rim to sever wood fibres & two scrapers to remove the majority of the wood after the rim has cut the outside edge. Forstner bits will also cut well in end grain without wandering & cut OK at an angle to the surface.

Many 'bargain' forstner bits are only made of High Carbon (HCS) steel, while better quality bits are High Speed steel (HSS) - the main preformance difference is that HSS is not affected by heating of the bit's rim, which is quite common in Forstner bits, while HCS bits can be thrown away after they start to smoke due to softening. Lee Valley & Carbatec both offer HSS and HCS bits, make sure you get/order the HSS ones, they are worth the few dollars extra in the long term.

[doug the slug]

......while better quality bits are High Speed steel (HSS) - the main preformance difference is that HSS is not affected by heating of the bit's rim.........


Brslee, i will stand corrected if necessary but i believe that it would be possible to damage an hss bit by overheating. i am always careful to avoid overheating my forstner bits and the hss router bits i use

[Ashore]

When you use a forstner bit it's advisable to use a lower speed so as to not overheat the larger the forstner the slower you go, thus if your drilling with a hand drill use a variable speed one. It is easy to get a feel for them once you have used them a couple of times.
the cheaper forstners can tear out at the bottom of the hole easily if you are not careful so I usually drill over a scrap piece of timber


Rgds

[fanlee]

Thanks guys. All this has been a great help.

RobSm.

[Ian007]

Forstner bits look like this, I think you know what a spade bit looks like.

Cheers Ian:)

picture kindly pinched from the carbatec web site:eek: