MoriMillMan
Aluminum
- Joined
- Jan 6, 2019
I’m using the 870 full tip inserts
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Largest Manufacturing Technology Community on the Web
Stay Connected:
Loosing the center of carbide tip drills...
- Thread starter mmurray70
- Start date
- Replies 31
- Views 7,075
I’m using the 870 full tip inserts
MoriMillMan
Aluminum
- Joined
- Jan 6, 2019
Hey sorry I misinformed you. Our replaceable top drills are ingersol quick twist and gold twist. Both I highly recommend although they are all I’ve used. Neither shows noticeably longer life or better performance to me.
For our bigger solid drills ( I just used used this yesterday - 1.68” 6.5” deep hole @ 4 ipm 900? Rpm?) we use the sandvik 880 and also performs very well I made 24 holes so far with these inserts and they show little wear.
Hope this helps give you a little data for your decision.
For our bigger solid drills ( I just used used this yesterday - 1.68” 6.5” deep hole @ 4 ipm 900? Rpm?) we use the sandvik 880 and also performs very well I made 24 holes so far with these inserts and they show little wear.
Hope this helps give you a little data for your decision.
Well you're limited by your equipment. That's okay, but you may need to look at other Tooling solutions, instead of trying to make a thing work. Indexable/Insert Drills pop to my head.
R
Thanks for the help guys. My Kennametal rep spoke with an engineer and now they suggest I try backing down to 0.005 IPR. I increased slightly to 0.006 and got 350 holes out of an insert before it wore out, and the center was fine. Gonna bump this up a little now with each new insert until I start breaking centers again. Im thinking somewhere around 0.008 IPR will probably give me the best results. Big drop from the 0.019 IPR maximum they list for this tool. But im still pretty happy with the drill overall. I like how the whole tip is carbide, no part of the body sticking up to be damaged. Inserts are easy to change. And the chips are nice. I just wish they gave me more realistic feedrates to start out with. Id probably buy another in 26.5mm but they dont make the KTFS this big.
I havent ordered the 26.5mm drill yet. Still leaning towards the sandvik 870. They estimate 600 holes per insert and if thats true it will be cheaper per hole then the kennametal im using now.
I havent ordered the 26.5mm drill yet. Still leaning towards the sandvik 870. They estimate 600 holes per insert and if thats true it will be cheaper per hole then the kennametal im using now.
memphisjed
Titanium
- Joined
- Jan 21, 2019
- Location
- Memphis
Can you spindle ramp up near the material approach and then ramp down to working rpms, kinda of fooling the tool into a slow start cut? It only took a 1/16" of initial feed lower to add the x 10 multiplier to hole count with our inserts (Allied's accent of the helix bit tip). Most of our holders are 5d.
Orange Vise
Titanium
- Joined
- Feb 10, 2012
- Location
- California
IME, replaceable tip drills start a little bit straighter and require a little less spindle HP. They are excellent above 6xD. But when they fail, they fail badly. The only machine window I've ever broken was due to a cracked replaceable tip drill.
6xD and below, on a lathe with tons of low RPM torque, I lean toward regular insert drills. If Sandvik is providing you with an 870 on guaranteed test, ask to test their 880 as well - one of my favorites.
This is bullshit. I would throw a fit. So KM advertised an MRR, it didn't work, and their solution is 30% MRR. Did you get 60% off the cost of the Tool? This is why I don't fuck with KM. I found one thing that I really like and know and buy, but I don't listen to their reps. Ask Curtis.
R
Just a little update. Its running reliably now at 0.007 IPR. I got 350 holes from an insert at 0.006 IPR, bumped it up to 0.007 and got 430. Tried it at 0.008 and it started off great but started to sound a little rougher after around 200 holes so i backed back to 0.007 again, got 411 holes in total out of that insert. Center of the tool is fine, just wear on cutting edges now. It obviously couldn't handle the higher feed in this material.
I bought the Sandvik 870 to try for the other job. Will post back how it works. Going to be interesting to see how they compare.
I bought the Sandvik 870 to try for the other job. Will post back how it works. Going to be interesting to see how they compare.
Hi guys I got this job finished now and just posting a follow up on how the Sandvik and Kennametal drills compared. The Sandvik 870 is the clear winner. It had no problem running at 0.012 IPR and gave me over 600 holes per insert, exactly what sandviks calculator predicted.
I had to run the kennametal drill at 0.007 IPR feed to avoid insert crumbling in the center, and then it struggled to get 400 holes per insert, and finally one of my kennametal drills jammed up and destroyed the whole drill part way through the job. The kennametal coolant holes exit about an inch back from the tip and this leaves the tip of the drill prone to rubbing and welding imo, poor design. The coolant holes actually push chips back towards the tip! I replaced this drill with another sandvik 870 and it ran WAY faster, quieter, cheaper per hole and seems to be much more reliable too.
I had to run the kennametal drill at 0.007 IPR feed to avoid insert crumbling in the center, and then it struggled to get 400 holes per insert, and finally one of my kennametal drills jammed up and destroyed the whole drill part way through the job. The kennametal coolant holes exit about an inch back from the tip and this leaves the tip of the drill prone to rubbing and welding imo, poor design. The coolant holes actually push chips back towards the tip! I replaced this drill with another sandvik 870 and it ran WAY faster, quieter, cheaper per hole and seems to be much more reliable too.
Murray
thanks for the heads up, its alwasy nice to hear real life info/end results on tooling
For future reference, Just remember the high cost of "customer supplied material". Generally this is someone trying to nickel and dime a job and will find whatever garbage steel the local foundry or mill has outside left over for pennies on the pound. It took me a while to learn this even after shoving round bar in my iron worker and chipping the die or a $300 bi metal blade on my saw only made one cut. remember many hot rolled steels (Not certed) have whatever is laying around tossed in the pot including re-bar thus introducing glass.
Not saying this is what happened in your case but it is quite possible. If a customer decides to supply their own material ask for a certification and if they don't have that it doesn't hurt to ask for a tooling deposit just in case you find the hard spot. I hate the sound of a broken tooth in a saw. You know there will be 1000 more before you get it stopped.
Not saying this is what happened in your case but it is quite possible. If a customer decides to supply their own material ask for a certification and if they don't have that it doesn't hurt to ask for a tooling deposit just in case you find the hard spot. I hate the sound of a broken tooth in a saw. You know there will be 1000 more before you get it stopped.
Similar threads
