[MBG]

Would it be a wise choose to switch to carbide drills since all of my HSS drills break? What I am doing is cutting pure iron round stock (production) about 500 a day I drill but I got to go easy on the drilling or else the HSS would break. Is there any benefit on going to a carbide drill to be able to drill faster and give more pressure while drilling?

[mxtras]

HSS in iron should last a very long time. Why are the drills breaking? Something is not right.

Carbide tools break also. I would find out why you are breaking your drills before you spend the money to start snapping more expensive drills. If you are wearing them out quickly then switch to carbide.

Scott

[MBG]

HSS in iron should last a very long time. Why are the drills breaking? Something is not right.

Carbide tools break also. I would find out why you are breaking your drills before you spend the money to start snapping more expensive drills. If you are wearing them out quickly then switch to carbide.

Scott

well they don't break until about 150 or so.... Then they break. I am running production and getting paid by the part so time is money here. When I push it I can make 14 an hour if I dont i'm making lik 9.... soo you know damn well i'm going to push it hah.. I just wnat to know if carbide will be able to hold up when i'm "pushing" it harder....

[mxtras]

Carbide is more brittle than HSS - it won't flex and twist the way HSS will, so in this case, I would not recommend carbide. I would recommend changing the drill after 125 holes or stopping for 15 seconds to grind new edges on it.

Scott

[MBG]

Carbide is more brittle than HSS - it won't flex and twist the way HSS will, so in this case, I would not recommend carbide. I would recommend changing the drill after 125 holes or stopping for 15 seconds to grind new edges on it.

Scott

yea... that is what I wanted to avoid is the time taking it out and putting it in... You know time is money.. I wnat to make the 14 an hour not the 8 an hour ahhahah

so what about another kind of drill is there any kind?

[Mcgyver]

whats different between the 1st one and the 150th one? tool wear. sharpen the drill if its big enough, if not toss it. also, what dia, and what do you mean by pure iron?

[MBG]

whats different between the 1st one and the 150th one? tool wear. sharpen the drill if its big enough, if not toss it. also, what dia, and what do you mean by pure iron?

the difference between the 1st and the 150th? really nothing finish is the same.. Just when I push it into the workpeice it just snaps... The diameter is .108 or something like that got it at the shop...


and it's pure iron I import it...

[mxtras]

I figured he meant cast iron, Mcgyver. Don't know about you, but I can drill cast for a week with the same HSS drill - it's like drilling butter.

Scott

[MBG]

I figured he meant cast iron, Mcgyver. Don't know about you, but I can drill cast for a week with the same HSS drill - it's like drilling butter.

Scott

no it isn't cast iron... It is pure iron like extruded or whatever I dont know but it's not cast it's a round round like 1/8 thick

[Mcgyver]

I can drill cast for a week with the same HSS drill - it's like drilling butter.
Scott

I've machined a cast iron many times but never in volume/production so I can't say first hand what the rate of tool wear is. I do like working it and agree the good stuff machines like butter, but that’s not necessarily the same as low tool wear and some cast is better than others and it can be abrasive. As drilling the hole isn’t the problem, but rather breakage after 10 hours of going at it, I figured it had to be tool wear + I’m still not sure what he’s drilling.

MBG I can’t follow your description – pure iron? round round like 1/8 thick? Like pure iron is in the element Fe?

[Mcgyver]

you guys type too fast, Scott, your earlier post basically says the same as mine, sorry either didn't see it or was too slow!

[mxtras]

I am with you on this one Mcgyver - I don't get it. Pure iron?

What is the ASTM # for the material, MBG?

Scott

[DareBee]

I would suggest you got A quick change toolholder, then you can have 3 drillbits always ready to go - would take 2 seconds to change drill and you can sharpen and reset the depth on the wore 1 between parts.

[MBG]

I would suggest you got A quick change toolholder, then you can have 3 drillbits always ready to go - would take 2 seconds to change drill and you can sharpen and reset the depth on the wore 1 between parts.

I do use two drills. I am doing it on a turret lathe so I got that revolving tool changer. I use two end mills and two drills..

[mxtras]

Before we comment any further on this I think it is fair for you to give us a good description of the material.

You said this is not cast iron but "pure iron" that you imported. If you imported it, then you must have the specs - give us the specs of this pure, imported iron please.

Why did you have to import this material yourself? The best iron in the world comes from right here in the states - where did it come from?? And what is the material called?

You asked for help, we need more info.

[MBG]

Before we comment any further on this I think it is fair for you to give us a good description of the material.

You said this is not cast iron but "pure iron" that you imported. If you imported it, then you must have the specs - give us the specs of this pure, imported iron please.

Why did you have to import this material yourself? The best iron in the world comes from right here in the states - where did it come from?? And what is the material called?

You asked for help, we need more info.

the guy that I am doing the parts for is supplying the materials so I dont really know. He says it works well with what he is doing...

[mxtras]

OK. Just change your drill more often. A dull tool is not the kind of thing to push - doesn't matter what it's made from - carbide, HSS, Cobalt - doesn't make a difference if it's dull.

Scott

[mxtras]

I thought of a good analogy for this -

If you continue to run into other cars and hit stuff while driving your Chevette, are you going to run out and buy a different car to solve the problem?

Scott

[jderou]

Is it possible the spindle runout is too great and the bits are work hardening until they break? Or they are walking off center (because of forcing them) on entry and again work hardening until breakage.
Can you shorten the length of the bit or anything else to stiffen it?

[mxpro32]

The material he is describing sounds like continuous cast iron. It is sold by the trade name durabar here in the US. It's billet cast iron with really good characteristics. It's carbon content is really homogenous and it is free of carbide and silica inclusions which wear tools. It's supposed to be 30-40% easier to machine than traditional cast iron and the strength is considerably greater as well due to the even distribution of carbon. Here is a good article on continuous cast iron.

http://www.production-machining.com/...es/030302.html

Also, it seems that carbide drill bits might just be the answer for him if tool wear is causing the breakage, because carbide bits would last significantly longer.