It matters. a LOT.
And that is why it matters - who is going to make or repair stuff when these skills are lost ?
It matters. a LOT.
And that is why it matters - who is going to make or repair stuff when these skills are lost ?
raywin
Well-Known Member
Use a centre punch,Well reading this thread I learnt that you should use coolant when drilling metal - so that's a positive
Any more tips for someone that doesn't really drill like me?
Cheers.
If you are drilling more than about 6 mm drill a small pilot hole first
If you are drilling into a hardened bolt or Allen bolt then use one of these but keep the speed down.
http://www.ebay.co.uk/itm/Cintride-...hash=item1ea0b5466d:m:mrjL_7SNmRho0kCR2zwat_A
Don't run with sissors
fozt
Active Member
Brilliant thanks.
I recently had an experience drilling into an Allen bolt, it was an absolute nightmare. Perhaps next time I'll be more prepared.
It just depends on what you call small.
potus
Well-Known Member
wattfield
AKA Dirk Diggler
Tip 5: Learn to spell the word "scissors".
raywin
Well-Known Member
Yes I'm a founder member of the UCN (national dyslexia association)Tip 5: Learn to spell the word "scissors".
Cruel trick using a word like that for such an affliction.
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brian47
Well-Known Member
One of the most awkward drilling jobs to do without the proper tools is drilling through a round bar or a pipe.
The safest and probably the easiest way to do it is to use "Vee" blocks or a fastened down drill stand vice and a vertical mounted or pillar drill, as well as a centre punch, eye protection, cutting fluid and the correct drill and feed speeds.
There are, or were some cheap bench mounts designed to take a hand held electric drill, Black and Decker (used) to do some for their drills. For occasional light work they can be OK .... just, but bear in mind their limitations and the fact that very slow drill speeds aren't really available with that type of drill, so you'll have to modify your work techniques to take this into account.
Of course, an even easier way is to get someone else to do it for you.
The safest and probably the easiest way to do it is to use "Vee" blocks or a fastened down drill stand vice and a vertical mounted or pillar drill, as well as a centre punch, eye protection, cutting fluid and the correct drill and feed speeds.
There are, or were some cheap bench mounts designed to take a hand held electric drill, Black and Decker (used) to do some for their drills. For occasional light work they can be OK .... just, but bear in mind their limitations and the fact that very slow drill speeds aren't really available with that type of drill, so you'll have to modify your work techniques to take this into account.
Of course, an even easier way is to get someone else to do it for you.
TorsionBhudda
Well-Known Member
+1 for Dormer cobalt drills it all we use at work and what i use at home. slow and steady is name off game when drilling metal and plenty cutting compound/fluid.dormer cobalt are what i use successfully ,but they do need sharpening like any drill, you might be better getting one of theses or similar
View attachment 100519
or buying in packs like theses
flat
Well-Known Member
I have one of those sharpeners and it works fine, I don't think it is as accurate as by hand to be honest as you just shove the drill bit in while it's turning and there is a bit if slack so the angle isn't perfect sometime - this is one I got from machine mart. However it does work.
I don't have a bench grinder anymore but I know how to sharpen on that to, it isn't overly hard but I can't do small bits on the grinder.
I tend to keep and reshape/sharpen the bigger stuff and small bits <5mm I just buy a few at a time
I still haven't been able to drill stainless neatly
I don't have a bench grinder anymore but I know how to sharpen on that to, it isn't overly hard but I can't do small bits on the grinder.
I tend to keep and reshape/sharpen the bigger stuff and small bits <5mm I just buy a few at a time
I still haven't been able to drill stainless neatly
As well as carbide tipped drills for drilling metal, I've sometimes ground a cutting edge on a spare masonry drill (with a 'green grit' grinding wheel) and used it to drill holes in hard things like cast iron, files and other bits of high carbon steel. If you're using a small workpiece that you can heat up, then getting it red hot and letting it cool slowly can help soften (or anneal) it. Putting it in a fire while the fire goes out over night is good for this. I used to make a lot of stuff out of angle iron from old bed frames. That's often tough stuff, and spring tempered too. Putting the ends I wanted to work on in a fire overnight made it a lot easier to cut, drill, bolt and rivet the following day.
And the drill bit is 0.3mmEspecially when your eyes are 50 years old....
Well, lots of feedback on this so thanks everyone.
In answer to earlier questions...
Using a hand drill on slow speed
Nope...ashamed to admit not using a cutting liquid - really didn't realise this was necessary for small jobs with hand drill...oops!
Trying to drill 8mm and 13mm holes in mild steel...pilot holes first
Drill bits are not even spiralling any swarf...its painfully slow
Drill bits are fairly new but nothing fancy
Appreciate the info on the drill bits...I will try them out and will get myself some lube/coolant
Yet again...more learnt on this forum.
In answer to earlier questions...
Using a hand drill on slow speed
Nope...ashamed to admit not using a cutting liquid - really didn't realise this was necessary for small jobs with hand drill...oops!
Trying to drill 8mm and 13mm holes in mild steel...pilot holes first
Drill bits are not even spiralling any swarf...its painfully slow
Drill bits are fairly new but nothing fancy
Appreciate the info on the drill bits...I will try them out and will get myself some lube/coolant
Yet again...more learnt on this forum.
If it's going slowly and with no spirals of swarf, it suggests your drills could do with a sharpen. If they're not producing swarf, then they're just skating on the surface, which makes heat and interferes with the temper. Drills are happiest when they're cutting something. If they're just skating they tend to blunt quite quickly.
raywin
Well-Known Member
Absolutely right vital that any cutting tool should cut not rub.
And while over speed is a problem with drills on small diameter drills don't go too slow, it makes life hard for both you and the drill.
Remembering my old tech collage days cutting speed for HSS is 80 - 100 feet per minute so if you get the diameter of the drill and multiply by 3.14 (in inches) then you divide that by 12, then divide the result into 80 gives you the correct rpm.
Hope I remembered that right, but if not I will soon be reminded.
I always found it a wee bit high and lowering it a bit helps with the less than ideal conditions we usually work in.
neilly
Well-Known Member
Similar ball park figures to what I was taught during my apprenticeship. Then a case of listen and look to tune what you were doing.
Cheers
I do drill grinding classes at work (using machine and manual method ) it is a skill that is being lost just as general machining is such a shame
the big mistake is that for thin steel you should alter the drill point angle use a centre punch to stop it running all over the place and use a drop of oil
the big mistake is that for thin steel you should alter the drill point angle use a centre punch to stop it running all over the place and use a drop of oil
raywin
Well-Known Member
Well it's good to know that at least some of theses skills are being carried forward. I remember "flattening" drill point angles for thinner metal gets more of the edge cutting before the chisel point breaks through. And boxing holes ahhh
It makes me sad that there are so few skilled engineers out there now I love my job I get to play with very big machines making /salvage parts for them
where I work we have a full machine shop I still get to do some screw cutting on the lathes ect very rare you see that now
where I work we have a full machine shop I still get to do some screw cutting on the lathes ect very rare you see that now
