Drill bits

[BBadger]

Evening all
After spending my sunny afternoon sharpening drill bits too no avail as there all buggered i have decided to get new ones!

Im looking for high quality stuff in a set that covers most sizes, as after having a search i dont know whats good and whats not.

So any recommendations and rough prices for somthing good.


Thanks
Brock

[Stuuk1]

What sizes are you after...?

I dont know makes of drill bit. But definitely do not buy the make 'defiance'. They are black bits and snap very very easily.

I get mine free from work...

[dirtydog]

What do you want to drill into? Or just general drill bits?

[Specialone]

Evening all
After spending my sunny afternoon sharpening drill bits too no avail as there all buggered i have decided to get new ones!

Im looking for high quality stuff in a set that covers most sizes, as after having a search i dont know whats good and whats not.

So any recommendations and rough prices for somthing good.


Thanks
Brock

What you doing with them?
Ocassional use then cheaper ones are fine, if you use them regular on a range of materials then get some tin coated ones or quality HSS.
Good drills can be sharpened a few times especially for a home users demand.

[madness]

Dormer is a good brand, but not that easy to get hold of. I'd recommend buying drills from an industrial engineering suppliers and not a diy store.

[BBadger]

Well they will generaly be drilling wood, brick, plaster, snapped swing arm and airbox bolts and so on.

The bits i use are my dads...and hes had them a while, whilst being good they are coming to the end of their life so ill be needing a whole new set essentialy.
Also ive seen some lovely ones from engenering firm but dear god there rediculously expensive.

[punyXpress]

You'll probably need metric ones, then ;)

[monkey]

Cobalt bits for the metalwork on your bikes although HSS or other cheaper ones sometimes do just as good a job.

Other than that boff up a bit on speeds for drilling stuff. The general rule is go slow for hard things and fast for softer things. For brick any old masonary bits will do. They're pretty much blunt to start off with.

[DarrenSV650S]

spending my sunny afternoon sharpening drill bits
:-s

[Specialone]

Dormer is a good brand, but not that easy to get hold of. I'd recommend buying drills from an industrial engineering suppliers and not a diy store.


+1 Most of my bits are dormer, i aquired some good sets from my last employer :)
One of the sets i have is a 0.5-6mm set in 0.1 increments, very precison :p

[Lozzo]

Evening all
After spending my sunny afternoon sharpening drill bits too no avail as there all buggered i have decided to get new ones!

Im looking for high quality stuff in a set that covers most sizes, as after having a search i dont know whats good and whats not.

So any recommendations and rough prices for somthing good.


Get a bunch of left handed ones as well, for removing broken screws. Have to be one of the best investments I've ever made

[timwilky]

How I used to hate grinding drill bits, lathe tools never a problem.

118° on a circular profile with clearance and balancing both cut edges. Hard work when you only do it every couple of years and then discover you have a hundred to do.

Far easier to put a stores rec in far a new batch

[Wideboy]

I got specialized bench grider at home for sharpening engraving tools ect, its got a swinging fence you can clamp your drill bits in, with a fine diamond wheel it does them perfect. at work i do it by eye one a bench grinder

i got a cheap set from aldi or lidle (sp). colbat coated, i bought 5 tins as i expected them to be crap plus im forever breaking bits, they were cheap but i've still got a tin left and i bought them over 2 years back..... very good value i've seen they still do them

[xXBADGERXx]

I`ve still got all my drill bits from my apprenticeship , they are HSS High Speed Steel bits and have lasted years . The trick with grinding drill bits is to make sure the cutting edge is the highest point (obviously) , relieve the back of the bit so it doesn`t rub on your work , make sure both cutting edges are of equal length and don`t have too much of a rake on them . When grinding a bit you literally just skim it over the grinding wheel and then quench it in Oil , don`t have it on the grinding wheel for too long otherwise you will overheat the bit and make it go soft .

My tip is to approach the wheel with the bit at the correct angle for it`s cutting edge , place it on the wheel and then curve over to the other side of the wheel like a Dyno Graph but without the drop off at the end , as you do this you are also rotating the bit . Minimal time is spent on the first approach so the cutting edge is made , then dwell a bit longer on the arc upwards to remove the material behind the bit , then quench it .

The knack of using drills is generally "the smaller the bit , the faster the speed" when drilling . If you are putting weight on the drill then you are either trying to take too much off when drilling or the bit is blunt . Drill in steps as well , if you have a big hole to do then drill a "Pilot" hole and then increase in 2mm sizes upwards to the desired diameter . This post is just a generalisation of sharpening , if you lived nearby I would come and show you how to do it , then watch you finish off the rest whilst I drink Tea and admonish you for your lack of technique .... whilst demanding more Biscuits .

[Specialone]

I`ve still got all my drill bits from my apprenticeship , they are HSS High Speed Steel bits and have lasted years . The trick with grinding drill bits is to make sure the cutting edge is the highest point (obviously) , relieve the back of the bit so it doesn`t rub on your work , make sure both cutting edges are of equal length and don`t have too much of a rake on them . When grinding a bit you literally just skim it over the grinding wheel and then quench it in Oil , don`t have it on the grinding wheel for too long otherwise you will overheat the bit and make it go soft .

My tip is to approach the wheel with the bit at the correct angle for it`s cutting edge , place it on the wheel and then curve over to the other side of the wheel like a Dyno Graph but without the drop off at the end , as you do this you are also rotating the bit . Minimal time is spent on the first approach so the cutting edge is made , then dwell a bit longer on the arc upwards to remove the material behind the bit , then quench it .

The knack of using drills is generally "the smaller the bit , the faster the speed" when drilling . If you are putting weight on the drill then you are either trying to take too much off when drilling or the bit is blunt . Drill in steps as well , if you have a big hole to do then drill a "Pilot" hole and then increase in 2mm sizes upwards to the desired diameter . This post is just a generalisation of sharpening , if you lived nearby I would come and show you how to do it , then watch you finish off the rest whilst I drink Tea and admonish you for your lack of technique .... whilst demanding more Biscuits .


Thats pretty much the same way i was shown, but tbh i dont sharpen small bits cos i never seem to get them as good and they are cheap, so below 3-4mm id chuck them and replace them.

Also, generally the harder the material the slower you go which goes hand in hand with the speeds for varying diametres of drill bits, there is various cutting speed charts around but most experienced people 'know' (within reason) what speed to use with different materials / drill sizes without thinking and look at the way it cuts and maybe adjust accordingly.

Ps i love biscuits...

[xXBADGERXx]

Aye , and a dab of oil doesn`t hurt when drilling , or go and buy some cutting oil from a supplier , comes in handy when tapping a thread as well .

[yorkie_chris]

Well they will generaly be drilling wood, brick, plaster, snapped swing arm and airbox bolts and so on.

The bits i use are my dads...and hes had them a while, whilst being good they are coming to the end of their life so ill be needing a whole new set essentialy.
Also ive seen some lovely ones from engenering firm but dear god there rediculously expensive.

No point buying a decent drillbit to drill into plaster!

[xXBADGERXx]

No point buying a decent drillbit to drill into plaster!

A wet finger is good enough around here .

On a side note , buy the right bits for the right Job , Masonry bits for home , Wood bits for DIY and HSS/Cobalt/Nitrided/Unobtanium bits for Metals (dependant on Hardness etc)

[Sir Trev]

Screwfix or Axminster sell reasonable sets and will have individual ones to replace the items you break or go dull.

I'm very lucky and have a branch of both within 500yards of each other less than a mile from my house. I also have a pukka shop aimed at the trade user even closer to home (Isaac Lord) who also have some very good quality kit.

All three do mail order.

[embee]

Dormer always used to be the benchmark for bits, I bought a set 30yrs ago and have only replaced a couple, they are in regular use.

Basically like the others say. You can find charts of cutting speeds for HSS driling into various materials, rpm vs diameter, this (http://www.ibiblio.org/twa/info/drillSpeedChart.pdf) was the first one up on the search, plenty of others available.

Cutting oils (drilling and tapping fluid) is ideal but any mineral type oil (engine oil/3-in-1 etc) will be an OK DIY substitute usually, it's mainly for cooling and preventing welding/pick-up.
Steel - cutting oil
Aluminium - ideally paraffin but oil will do
Brass - none
cast iron - none

If you ever try drilling lead, use plenty of oil (don't ask me how I found out).

Don't use your "best" metal drill bits in wood, they easily overheat due to friction in the hole. Everyone does use metal cutting bits in wood, including me, but the most important thing is to frequently withdraw while still turning to remove "swarf" while drilling deep holes in wood. If it starts smoking it's far too hot. Use wood bits (lip&spur/forstner etc) when possible.

Masonry bits are actually chisels which are hit into the masonry and then turned and hit again, it's the hitting which breaks the masonry not the turning. SDS is the best way to drill masonry bar none. Masonry bits do not have sharp edges, the "cutting" edge is like a slightly skewed cold chisel and is usually somewhat blunt to prolong the edge, sharp edges just break away and chip. Get in the habit of using a plastic bag held under the hole with masking tape to catch most of the masonry dust, it saves an awful lot of clearing up.

[BBadger]

This is the thing all bits that are left are dormer but their older than me so they are ok now sharpened but dont stay that way long especially as its summer and works getting done round the house.
Ill check out the screwfix ones for now as they seem reasonable and can see how they last for now.

Thanks guys some handy tips in there too.
Brock.