METAL DRILL BITS???

[HYBRIDNI]

Can anybody suggest some good quality drill bits that will last more than a few goes in 3-6mm steel?

I am currently using gold coloured cobalt bits but they seem not much better than the standard hss black ones.

 

[brian47]

A bit more information might be required before somebody can give you a proper reply:-

• Diameter of the drill bit
• Type/quality of the steel being drilled
• What coolant you're using
• Bench drill press or hand tools
• Drill bit speed
• Applied drilling pressure

 

[listerdiesel]

Most folks haven't a clue about drills, they just use them until they don't work

As Brian says above, we need to know a bit more before commenting.

I drilled some 12mm steel plate on the weekend, no trouble at all, but the drill speed and feed were correct and I wasn't trying to do it in 10 seconds flat. Take your time and we also use a high-sulphur cutting oil if it's something a bit tough.

Peter

 

[flat]

Yeah I have some cobalt tipped ones and they are lasting absolutely fine

How are you using them?

 

[ER1C]

Can anybody suggest some good quality drill bits that will last more than a few goes in 3-6mm steel?

I am currently using gold coloured cobalt bits but they seem not much better than the standard hss black ones.

I had this same problem and then my dad (engineer) saw my drilling one day..... "what the hell are you doing son, you aren't drilling wood".... at the time I had no idea there was a difference. For metal the drill should be a massive amount slower, as slow as can be.... even though it may not look like its doing anything as long as you can see filings coming off its working. If you max out on the drill you will blunt any known drill for under £50

 

[jamesmartin]

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

or buying in packs like theses

 

[raywin]

Quite honestly forget, Cobalt, titanium plated, or whatever, to drill mild steel get some decent HSS twist drills made by an old reputable company either Dormer, Eclipse or similar, they are not the cheapest but when you have been using them a few years you will see why.
And importantly learn to sharpen drills, or get a sharpening gizmo, that way you can keep using them, all drills will blunt with continued use but you can keep sharpening good ones, some of mine are 35 - 40'years old.

 

[Brown]

The other thing that might help is if the drill bit has overheated (often shown by being a bluish colour) it might benefit from being hardened and re-tempered. The hardening bit involves heating it to red heat and quenching suddenly (I use water, some people prefer oil). Then if you clean a bit of the oxide off so you can see the colour of the metal you heat it again, only not so hot this time. Traditionally, people used to tell the temperature by the colour of the oxide layers. which change as the metal heats up. 'Dark straw' or 'brown-purple' is about where you want to be. If you go too far, just re-harden and start again. Even cheap drill bits can sometimes be made quite tough by a quick harden and temper. As a teenager I used to sit watching the telly doing this in a blowtorch flame with the family's stock of drill bits after my father and brother had blunted them all. Nowadays I have less time and more money so I tend to just order some more drills.

 

[chrisstdt]

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

Are those drill sharpeners shown in the pic any good ?

 

[wammers]

Are those drill sharpeners shown in the pic any good ?

Don't need drill sharpeners just a bench grinder and the knack. Using drills at to fast a speed is what knackers most up. Use only good quality bits, the ones for £9.99 a set are a waste of space unless you are drilling butter.

 

[cooltide]

Don't need drill sharpeners just a bench grinder and the knack. Using drills at to fast a speed is what knackers most up. Use only good quality bits, the ones for £9.99 a set are a waste of space unless you are drilling butter.

I also find they work better turning clockwise

 

[Thor1950]

I also find they work better turning clockwise

that depends, some need to be used counter clockwise.

 

[raywin]

Don't need drill sharpeners just a bench grinder and the knack. Using drills at to fast a speed is what knackers most up. Use only good quality bits, the ones for £9.99 a set are a waste of space unless you are drilling butter.

I suspect the people with the knack are getting less and less every year.

 

[blue beasty]

I suspect the people with the knack are getting less and less every year.

Something that's worth passing on. It bothers me that so many basic skills are being lost.

It probably doesn't matter but it feels like it should.

 

[cooltide]

that depends, some need to be used counter clockwise.

Casted out, sat back, opened a tinny and
caught myself a Thor

 

[raywin]

Something that's worth passing on. It bothers me that so many basic skills are being lost.

It probably doesn't matter but it feels like it should.

One thing I have spent time thinking about.
Back in 1970 I was a craft apprentice and some good skilled men passed to me a set of skills which have provided me with a good living ever since, the original plan was that we were just the keepers of these skills until we passed them on to future generations.
Somewhere along the line the chain was broken by people who were so short sighted they saw no profit in apprentices, and while I try to help any younger people I sometimes feel that the plan is so far off track that what I learned will dissapear when I retire in a couple of years.
No point in getting political about this but it feels so wrong, especially when they speak so "skill shortages" skill is still there we just need people with the vision to use and preserve it.

 

[chris7]

Why bother to learn when you can pay someone to do it.....seems to be the attitude.....problem is my generation are not passing these once handed down skills.....

Something that's worth passing on. It bothers me that so many basic skills are being lost.

It probably doesn't matter but it feels like it should.

onto their sons....

 

[jamesmartin]

Don't need drill sharpeners just a bench grinder and the knack. Using drills at to fast a speed is what knackers most up. Use only good quality bits, the ones for £9.99 a set are a waste of space unless you are drilling butter.

small bits are hard to sharpen on a bench grinder

 

[jamesmartin]

Are those drill sharpeners shown in the pic any good ?

ive got a drill doctor thats good for anything 4mm up, those other types are ok but will do smaller bits too, i use them regularly

 

[jamesmartin]

Something that's worth passing on. It bothers me that so many basic skills are being lost.

It probably doesn't matter but it feels like it should.

i can and was taught to sharpen drills but why bother when you can get kit that does it better