Need Help!- Drill bits for Stainless Steel

[Khalid]

I need to get information of the comapnies that sells best quality drills for drilling Stainless and other exotic materials.. I am looking after the drills that have removable insert tips..
Any help will be highly appreciated

[neilw20]

I know of them but have not used them. Other iscar products I use a quite good.
http://www.iscar.com.au/ProductLines...neDetailID/326

[Shotout]

Originally Posted by neilw20 I know of them but have not used them. Other iscar products I use a quite good. http://www.iscar.com.au/ProductLines...neDetailID/326

I'll second that recommendation. The Cham drills from Iscar are a real nice product. I've used them in different insert grades in 17-4 and 18-8 stainless as well as ductile and gray iron. Have a titanium job coming up I ordered some tips for as well. We ran them production in the last shop I was at and I figured the tool cost, without resharpening and re-coating, as $.068 per hole which compared to $.12 per hole for Sandvick Delta drills (brazed on coated) and $.28 for regular brazed on carbide tipped drills. The speeds and feeds are pretty high and surface finishes are nice. I also like the fact you can get them in 8X the dia for deep hole drilling or if you need to reach through a void and drill inline.

[dertsap]

Originally Posted by Khalid I need to get information of the comapnies that sells best quality drills for drilling Stainless and other exotic materials.. I am looking after the drills that have removable insert tips.. Any help will be highly appreciated

I recall you mentioning in the past that you had a problem with run out , if your going to use carbides then your going to need to be sure to have your drill running dead center or you'll greatly reduce the tool life

[Khalid]

Thank You Neil, Shotout and Curt for your feedback.. I have seen the website and its really interesting... I have also searched another website
http://www.sumicarbide.com/whatsnew_products.htm
Curt.. Actually these drills will be used on the Radial drill Machine (Novisa and Bergonzi)... These machines are from Italian origin and having very good quality in all respect...

We currently using drills from Dormer and Presto but i think there is something quality issues.. May be their are some more companies copying and making cheap drills with their name..

[Shotout]

Originally Posted by Khalid Thank You Neil, Shotout and Curt for your feedback.. I have seen the website and its really interesting... I have also searched another website http://www.sumicarbide.com/whatsnew_products.htm Curt.. Actually these drills will be used on the Radial drill Machine (Novisa and Bergonzi)... These machines are from Italian origin and having very good quality in all respect... We currently using drills from Dormer and Presto but i think there is something quality issues.. May be their are some more companies copying and making cheap drills with their name..

I tested the Sumitomo drills and found them lacking in these respects:
1. Tool life. I ran the normal Iscar drill on the left hand part and the Sumi drill on the right hand mirror image part. I had to dig it up but the Sumi drill failed @ 1890 dia17.5mm thru holes (48-49mm thick boss). I changed the tip as per schedule on the Iscar drill @ 2160 holes without tool body loss. As it was a head to head test and the speed feed ranges compared they where both run at the same speed and feed.
2. Ease of insert replacement when compared to Cham drills. The Iscar system uses a hand tool to simply twist and release;lock rather than screws.
3. Cost. Bodies where about $30 USD more and tips about $5 USD more.
4. Availability of product. This was over a year and half ago but it wasn't as good as Iscar and could have resulted in lost production time. Now this was in the grades we used on cast iron but based on the website info "Other tips specifically for cast iron, stainless steel and exotic materials are also available upon request" say to me that probably hasn't changed. These are stock items with Iscar.

Now hole size was in the same tolerance range between both drills and the surface finish was comparable. This was all in ductile iron too so the test data differences for stainless might not be as pronounced.

[dertsap]

I've always had good results from kennametal drills ,and its fairly cheap to get the inserts resharpened and recoated , just be sure to have sufficient coolant , because you will generate a lot of heat and once some of these stainless steels and many of the exotics get work hardened then your in for a nightmare

[Geof]

Originally Posted by Khalid .... Actually these drills will be used on the Radial drill Machine (Novisa and Bergonzi)... These machines are from Italian origin and having very good quality in all respect.....(

I am dubious about using insert drills on a Radial Drill.

Radial drills are very stiff vertically but not radially and they rely on the self-centering action of a conventional drill bit. It is possible that an insert drill would try to "walk around" because they are not self-centering.

[dertsap]

single insert drills are self centering but won't like any amount of movement (play)

[Khalid]

Originally Posted by Geof I am dubious about using insert drills on a Radial Drill. Radial drills are very stiff vertically but not radially and they rely on the self-centering action of a conventional drill bit. It is possible that an insert drill would try to "walk around" because they are not self-centering.

Thats the reason, we will first centre drill by using ordinary drill/ or by using the centre drill inserts.. You can say it a pilot drill.. I have seen some inserts too that having both in one drill...

Our radial drills having locking actions against radial movement...

[Khalid]

The attached drilling job was done manually on NOVISA radial drill... May I ask a question, is it possible to CNC the radial drill...
I am thinking to make a movable bed for it ..the other possibility is to make the ARM movable against its centre axis...

[dertsap]

Originally Posted by Khalid Thats the reason, we will first centre drill by using ordinary drill/ or by using the centre drill inserts.. You can say it a pilot drill.. I have seen some inserts too that having both in one drill... Our radial drills having locking actions against radial movement...

you can get the flat bottom drills with the centering insert but you will probably destroy it on a radial drill , if you choose to use the single insert carbide drill then you can not center drill or predrill or the tool will fail as well