Thread: Drill Bits

I would like to know this also. I occasionally have them explode or snap off the tips. I bought a set of Dewalt 'titanium' drill bits which so far has been great but others may have a different opinion on this set

Can of worms time

It all depends on what you are drilling, how big the hole, how deep, feed rate, drill speed, drill type and your level of patience. Do you center punch your work piece?

I use Bosch Brad points for Timber holes 2mm - 6mm. The 5mm version is the most common used, perfect size for the Woodfast Screw Chuck. Sutton Tools drill bits for larger holes 7mm - 25mm. I try to keep bits that use in timber separate from metal bits.

I use various drill and impact drivers, Bosch 10v, Milwaukee 18v, Makita Hammer to my Fidax Bench drill, cast iron beast.

+1 for Sutton if you're willing to pay that much.

The TTI drill bits from Total Tools are a great alternative for a smaller budget.

For timber it's very hard to go past Colt Five Star Brad Points (used to be German, but now made in France). They are High Speed Steel so handle much more heat than Tool Steel, don't rust as easily. Because they are harder steel they retain sharpness longer, but this does make them more brittle than Tool Steel. I've only broken a couple of vey small ones (3mm and 1/8").

Range of sizes is good:
3 to 16mm with 0.5mm increments fron 4.5 to 10.5mm
1/8" to 1/2" in 1/64 increments.

This is a 10mm tip (pardon the dust):




They also have Forstner bits in a huge range of sizes (High Alloy steel range and a HSS range with pilot bit).

However, the range of sizes in Brad Points and Forstners locally available from retailers is tiny and expensive. Click.

Famag (German) and Fisch (Austrian) also get favourable write ups, but are not available here to the best of my knowledge.

For metal drilling I think the Metalheads would say Sutton Vipers are the pick out of the Sutton range (they are still made in Oz, but most of their other lines are "made elsewhere").

I keep a few different sized centre drills handy for the odd small-hole drilling, either just to start the hole or (in thin stuff) complete the hole. I find these a lot better with hand held drills than normal drill bits.

Fence Furniture, that is a really great picture of the drill.

I can't comment on brands for the brad point bits, although I will admit they do make life a lot easier for timber to avoid drill wander.

With metal, do yourself a favour and invest in a top notch set. A fractional set from 1/16" to 1/2" by Sutton or P+N might cost a fair bit of dough, but if you have a sharpener or are blessed with the ability to freehand sharpen, they will last for years (at least the ones over 1/8" will, the smaller ones are easy to break at the best of times).
Another brand I have found to be rather good and fairly priced is Alpha. Our local industrial supplier sells them and they have proven to be good for workshop use.
Bosch make pretty well all the other obscure drill bits for ceramic and masonry etc. and have a decent reputation.

Drill care makes a large difference. Drilling at the right speeds, clamping your work, and using the right lubes (with metal) all make drill edges last so much longer.

If you use a hand-held drill a lot, the way you hold the drill can cause snappages. The arm that provides the force should be as close to the axis of drill rotation as possible to reduce lateral force on the drill bit.

If you drill sticky things (resinous timber, aluminium alloys, some stainless steels) then coatings, such as TiN, may help. They reduce the friction at the cutting edge, allowing swarf to be ejected without build-up on the cutting edge. Also helps reduce heat.
If you are drilling hard and tough things, then cobalt HSS drills are the way to go. They certainly aren't cheap, but if you have a lot of holes to drill in a hunk of stainless, they will mend your heartache.

For your ceramic needs, you'll want carbide tipped drills designed for the job, their tough tips both resist wear incredibly and are ground at a rake angle that allows the bit to essentially scrape the ceramic away without digging in and causing cracks.

Brittle plastics also require special drills, that have a small included tip angle and a neutral rake on the cutting edge. They can be ground out of regular jobber drills, or bought but are hard to find in a lot of stores. Be careful with a regular bit and you should be OK.

I think I might have started waffling here (I like drills, cut me some slack ), but with any luck there might be some useful info in there.

Cheerio
Tom