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Drilling forged 317

Crowndroyal

Plastic
Joined
Jun 3, 2019
Location
Sarnia
Looking for advice or options for drilling on forged 317.
Blueprint says SA 182 317/317L

Material is 205mm thick hole size is 25.6 mm, using an intimidator 120.

Material has been machined down from raw forge and set up on four blocks and clamped down in a x pattern. Blocks are about 2 inches tall roughly 1600 holes.

Have 2 different drilling tools
KSEM1000R10SS125 DRILL BODY
KSEM1011SPL INSERT

Currently drilling the Kenna at 700 rpm at 51mm/min
Center of the insert breaks off around 20 to 30 holes sometimes only get 3 holes before it breaks.
Hole size was also an issue when changing feeds and speeds ( can't remember off hand what numbers were tried )

Coolant pressure is around 500 to 530 at about 3 to 4 gpm

ISCAR ICM 1012 IC908 with matching size drill body
Currently drilling this setup at 500 rpm 90 mm/min get about 30 holes on insert before go/no go gauge gets tight. Also getting crunch noises once in awhile which im assuming are just chips not clearing tried higher rpm lower feed but hole size was all over and swirls on finish.

Coolant pressure is 500 psi with 4.9gpm
Oh holes are also being spot drilled to 5.08 mm depth on both setups. The iscar also tends to rub edges of spot before entering hole.

Need any other info just ask csnt thinknof what else would be needed at time of posting

So question is what feeds and speeds or procedure would be recommended
 
Dont waste your money on any more kennametal drills! Their new tip geometry is very weak and it just simply cracks randomly leaving your expensive drill insert useless. They will be quick to blame your machine and your setup, but in reality its just their inserts with their stupid new tip design. I ran into this exact problem with a Kennametal KTFS drill this summer. Cost me a small fortune. Would loose the center randomly. Sometimes halfway through an inserts expected life, sometimes just after a few parts. I tried all sorts of things, but kept randomly loosing drill tips even at way less then half their recommended feed. Read this post here: https://www.practicalmachinist.com/...e-tip-drills-363417/?highlight=loosing+center

I bit the bullet on cost of drill body and changed to a Sandvik 870 series drill and I cant even begin to tell you how much better they are! Drilled nearly 12,000 3" deep holes in steel this summer with the 870 and absolutely no surprises with the sandvik drill at all. Not a single insert chipped prematurely. Ran it at their recommended feed and everything worked perfectly.

The sandvik inserts cost about 25% more then kennametal, but I could run nearly twice as much feedrate, I would get about twice as many parts per insert, It ran much quieter, The Z axis load was WAY lower for a given feedrate and most of all it was sooooo much more reliable. Never even the slightest hickup. You constantly had to babysit the machine with the kennametal drill because you never know when the center of the drill tip was going to explode. I had one KTFS tip that broke and everything jammed up and took out the holder.

Also, FWIW im not totally against kennametal and just bashing their product. I still love their solid carbide milling tools, they are still my first choice here. But their insert drills suck. Cut your losses now and move on to something else. Best of luck with it20191119_235623.jpg
 
What are you spotting with? if its a 90°(or less to the following drill tip) you will be damaging the insert as it enters the hole.

Ideally you should spot 1.5xD deep with a stubby Sumocham then follow up with the (im assuming) 8xD drill.
 
Spotting with the same type insert as drilling just in a short kennametal spotting body thats like 2 inches long.
Same with the iscar inserts etc.
 
Dont waste your money on any more kennametal drills! Their new tip geometry is very weak and it just simply cracks randomly leaving your expensive drill insert useless. They will be quick to blame your machine and your setup, but in reality its just their inserts with their stupid new tip design. I ran into this exact problem with a Kennametal KTFS drill this summer. Cost me a small fortune. Would loose the center randomly. Sometimes halfway through an inserts expected life, sometimes just after a few parts. I tried all sorts of things, but kept randomly loosing drill tips even at way less then half their recommended feed. Read this post here: https://www.practicalmachinist.com/...e-tip-drills-363417/?highlight=loosing+center

I bit the bullet on cost of drill body and changed to a Sandvik 870 series drill and I cant even begin to tell you how much better they are! Drilled nearly 12,000 3" deep holes in steel this summer with the 870 and absolutely no surprises with the sandvik drill at all. Not a single insert chipped prematurely. Ran it at their recommended feed and everything worked perfectly.

The sandvik inserts cost about 25% more then kennametal, but I could run nearly twice as much feedrate, I would get about twice as many parts per insert, It ran much quieter, The Z axis load was WAY lower for a given feedrate and most of all it was sooooo much more reliable. Never even the slightest hickup. You constantly had to babysit the machine with the kennametal drill because you never know when the center of the drill tip was going to explode. I had one KTFS tip that broke and everything jammed up and took out the holder.

Also, FWIW im not totally against kennametal and just bashing their product. I still love their solid carbide milling tools, they are still my first choice here. But their insert drills suck. Cut your losses now and move on to something else. Best of luck with itView attachment 270481

We are running the spl's on one machine and on another iscar.
Also tried running kennametal HPL which seemed to work better bit have a extreamly small amout of them , also ran kennametal HP'S both of the later the centers held up but holes would go out of tolerance in some spots due to what we believe are just hard or soft spots in the forged 317.

I believe the SPL's are bouncing in the hole also get vibration in the material from time to time.


Kennametal did come and gave us some of them inserts you pictured we ran them at about 3.5/4.5 ipm through 4 inches of 317 got about 300 holes out of them.
What were you drilling with them again and at what feeds and speeds. We did not run them anywhere close to what they claimed they could run at as ot would be costly if something happened to the material.
 
Dont waste your money on any more kennametal drills! Their new tip geometry is very weak and it just simply cracks randomly leaving your expensive drill insert useless. They will be quick to blame your machine and your setup, but in reality its just their inserts with their stupid new tip design. I ran into this exact problem with a Kennametal KTFS drill this summer. Cost me a small fortune. Would loose the center randomly. Sometimes halfway through an inserts expected life, sometimes just after a few parts. I tried all sorts of things, but kept randomly loosing drill tips even at way less then half their recommended feed. Read this post here: https://www.practicalmachinist.com/...e-tip-drills-363417/?highlight=loosing+center

I bit the bullet on cost of drill body and changed to a Sandvik 870 series drill and I cant even begin to tell you how much better they are! Drilled nearly 12,000 3" deep holes in steel this summer with the 870 and absolutely no surprises with the sandvik drill at all. Not a single insert chipped prematurely. Ran it at their recommended feed and everything worked perfectly.

The sandvik inserts cost about 25% more then kennametal, but I could run nearly twice as much feedrate, I would get about twice as many parts per insert, It ran much quieter, The Z axis load was WAY lower for a given feedrate and most of all it was sooooo much more reliable. Never even the slightest hickup. You constantly had to babysit the machine with the kennametal drill because you never know when the center of the drill tip was going to explode. I had one KTFS tip that broke and everything jammed up and took out the holder.

Also, FWIW im not totally against kennametal and just bashing their product. I still love their solid carbide milling tools, they are still my first choice here. But their insert drills suck. Cut your losses now and move on to something else. Best of luck with itView attachment 270481

Another vote for Sandvik 870 drills. They are unreal.
 
We are running the spl's on one machine and on another iscar.
Also tried running kennametal HPL which seemed to work better bit have a extreamly small amout of them , also ran kennametal HP'S both of the later the centers held up but holes would go out of tolerance in some spots due to what we believe are just hard or soft spots in the forged 317.

I believe the SPL's are bouncing in the hole also get vibration in the material from time to time.


Kennametal did come and gave us some of them inserts you pictured we ran them at about 3.5/4.5 ipm through 4 inches of 317 got about 300 holes out of them.
What were you drilling with them again and at what feeds and speeds. We did not run them anywhere close to what they claimed they could run at as ot would be costly if something happened to the material.

I was drilling mild steel. Ran around their recommended SFM, started at 0.010 IPR and they recommended me to try higher (0.012) but this cracked even more centers. Got best results around 0.007 IPR but it still wasnt reliable. Still cracked some. And finally wiped out the whole tool when a center went out.

Their inserts have different shapes for the center based on material. The stainless inserts for this drill had a different tip design, maybe they would have worked better. But the tip on the steel inserts is way to pointy, its weak, and it cracks off. Its just a bad design. Take a look at this pic. Look how thin it is, this should explain everything.
 

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Looking for advice or options for drilling on forged 317.
Blueprint says SA 182 317/317L

Material is 205mm thick hole size is 25.6 mm, using an intimidator 120.

Material has been machined down from raw forge and set up on four blocks and clamped down in a x pattern. Blocks are about 2 inches tall roughly 1600 holes.

Have 2 different drilling tools
KSEM1000R10SS125 DRILL BODY
KSEM1011SPL INSERT

Currently drilling the Kenna at 700 rpm at 51mm/min
Center of the insert breaks off around 20 to 30 holes sometimes only get 3 holes before it breaks.
Hole size was also an issue when changing feeds and speeds ( can't remember off hand what numbers were tried )

Coolant pressure is around 500 to 530 at about 3 to 4 gpm

ISCAR ICM 1012 IC908 with matching size drill body
Currently drilling this setup at 500 rpm 90 mm/min get about 30 holes on insert before go/no go gauge gets tight. Also getting crunch noises once in awhile which im assuming are just chips not clearing tried higher rpm lower feed but hole size was all over and swirls on finish.

Coolant pressure is 500 psi with 4.9gpm
Oh holes are also being spot drilled to 5.08 mm depth on both setups. The iscar also tends to rub edges of spot before entering hole.

Need any other info just ask csnt thinknof what else would be needed at time of posting

So question is what feeds and speeds or procedure would be recommended

.
SS if has hard spots of slag in metal will damage any cutter especially if grain of rice size or bigger. like totally damage cutter 10 each new drills tried one after another. dont matter if somebody says they drill a million holes a seconds and drill bit still working after 50 years and never needed sharpening. if slag hard spots are smaller it just dulls cutting edges faster so shorter tool life just needs to be expected with that part material
.
if its a part material problem usually harder material you lessen ipt feed cause it will break cutter edges with the harder material. also drill bit length and tool holder length are usually very important factors as longer drills tend to vibrate enough to damage cutting edges basically when drill is 2x longer it flexes 2x2x2 or 8x more and if drill 3x longer it vibrates 3x3x3 or 27x more
.
some cnc when pecking drill it rapids in 0.100" from last peck when it goes back to feed. if long chip sticking up in hole this distance may need increasing so not drilling at rapid. usually a parameter adjustment. if hole still full of chips when drill reenters pecking it hits the chips compressed at bottom of hole at rapid. slowing rapids often helps
 
I was drilling mild steel. Ran around their recommended SFM, started at 0.010 IPR and they recommended me to try higher (0.012) but this cracked even more centers. Got best results around 0.007 IPR but it still wasnt reliable. Still cracked some. And finally wiped out the whole tool when a center went out.

Their inserts have different shapes for the center based on material. The stainless inserts for this drill had a different tip design, maybe they would have worked better. But the tip on the steel inserts is way to pointy, its weak, and it cracks off. Its just a bad design. Take a look at this pic. Look how thin it is, this should explain everything.

It sounds like the tip is failing upon entry, and looking at that grind my guess is that it has no support because the outer isn't in the hole yet. Definitely try a spot drill, this way when the insert makes contact it's supported by the cutting edges.
 
.
SS if has hard spots of slag in metal will damage any cutter especially if grain of rice size or bigger. like totally damage cutter 10 each new drills tried one after another. dont matter if somebody says they drill a million holes a seconds and drill bit still working after 50 years and never needed sharpening. if slag hard spots are smaller it just dulls cutting edges faster so shorter tool life just needs to be expected with that part material
.
if its a part material problem usually harder material you lessen ipt feed cause it will break cutter edges with the harder material. also drill bit length and tool holder length are usually very important factors as longer drills tend to vibrate enough to damage cutting edges basically when drill is 2x longer it flexes 2x2x2 or 8x more and if drill 3x longer it vibrates 3x3x3 or 27x more
.
some cnc when pecking drill it rapids in 0.100" from last peck when it goes back to feed. if long chip sticking up in hole this distance may need increasing so not drilling at rapid. usually a parameter adjustment. if hole still full of chips when drill reenters pecking it hits the chips compressed at bottom of hole at rapid. slowing rapids often helps

Go away already.
 
That takes time something we don't have atm we are already behind.
But guess i will just keep pounding away at it with the iscar and kennametal spl's
 
It sounds like the tip is failing upon entry, and looking at that grind my guess is that it has no support because the outer isn't in the hole yet. Definitely try a spot drill, this way when the insert makes contact it's supported by the cutting edges.

In my case, the tips were failing all over the place. Some on entry or shortly after, some halfway, some almost at the bottom. There was no obvious part of the cycle causing the problems. Wasn't happeneing only on entry.

Also Kennametal said these drills (at 5D length) did not need a start drill.
 








 
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