Indexable insert drills- Sandvik's 880 vs Tungaloy's Tung Twisted TDX
Our company recently began manufacturing more of our parts. We needed to drill 3,4, and 5xd holes in 17-4 Stainless steel with an indexable drill, and we talked to Tungaloy representatives in our area, including one individual who staffed the Tungaloy booth at last years IMTS show in Chicago.
The reps recommended Tungaloy Twisted drills. They showed me a drill- the drill really looked impressive- nice nickel plated finish, nice geometry etc. We bought 7 or so of the twisted drills at their recommendation.
It took us ~4 months to begin making chips on the machines these were intended for. We hired a 20+year mill-turn machinist to lead the new turning cell. Our machines have 25HP main spindles and 1000PSI M30-70 chip blasters, running Master Chemical Trim E206 coolant at 10% concentration [we've been thinking about going to Qualachem Xtreme Cut 292 but haven't yet]. We had a lot of trouble getting the Tungaloy drills to perform consistently. After about 4 days working with the drills, having damaged one TDX340W40–4 4Xd holder body and replaced it with a TDX340W40–5 5xd body, we had them at about 290SFM, pushing a feed of about .0041”/Rev. We had tried speeds up to 450SFM, and feeds .0035-.0059/rev. The smoothest we could get the drills to be, they screamed like an apparition, and made the machines vibrate in the 3-5Xd depth region. At their worst, they made the concrete vibrate and the machines seemed about ready to start walking around on the floor. We really felt like we were beating up our brand new machines using the TDX drills. Some insert edges would go 20 minutes, others 7 or 13, and the process was so unstable the machinist couldn’t really leave 1 machine to check a part at another. After drilling a few hundred holes, we realized part of the insert used in the initial cut would later be used and part of another edge. So there really were only 2 ACTUALLY CLEAN insert edges per insert set. (This doubles the cost of a pair of inserts). The marketing suggested 4 edges, but our practical application showed 2 real indexes per insert set. That probably was the condition causing spotty insert life. The production rate was slow under ideal conditions with the Tungaloy drill, and slower with the machinist second guessing and checking the insert condition, having to stop machines when inserts chipped or failed prematurely etc.
We switched products to the Sandvik 880-D3400L40-05, and instantly the unstable process stabilized. We tuned the drill in only 2-3 cuts (25 minutes of production time) and settled on 391SFM at .0055/rev. The drilling time per hole decreased by 45% [51 seconds faster per hole]. The 880 gave us Fanuc tracked tool life of 13 minutes per insert edge, and gave us 4 predictable indexes. The machine vibration was gone. Spindle loads dropped substantially. Feed loads dropped 30%. We drilled over a thousand holes on one body, and our machinists were able to operate 3 machines and get their focus and efficiency back.
Production speed greatly increased, and we drilled over a thousand holes on the Sandvik 880-D3400L40-05 without an issue. Our second Sandvik drill to go into a machine- a A880-D0625LX19-03, was tuned in 2 cuts, and produced 1500 holes.
The Tungaloy product for us was a waste of time and money. The first drill body was destroyed in a couple dozen holes. The tuning time cost us $1000 of payroll, and probably several times that in lost production time. Sandvik mops the floor with the competition. It’s not really even comparable. The only negative point for Sandvik is the higher insert cost. The drill body costs are comparable, but the insert pricing makes them a little less attractive. We’ve had trouble getting decent discount pricing on sandvik inserts and tools so we do as little business with Sandvik as possible unfortunately. Iscar is where we currently do probably 60% of our purchasing.
Tungaloy reps (local and regional) showed up thursday. They said they wanted to work with me implying a return for refund on my tungaloy drills. I told them I would be happy with 60 cents on the dollar as it would be better than being totally hosed. The conversation shifted to developmental discussion as they pumped me for information on product shortcommings and discussed how Tungaloy could improve the tung twisted drill (developing more aggressive stainless chip formers, sharper edge prep options for free cutting, different insert geometry to keep edges from being used on more than one index etc) covering exactly how it failed to work in my 35rc application (free research and development for tungaloy).
I was busy managing a sump cleanout and two mill turn part prove outs, but paused to talk with them. They shifted the conversation to trying to sell me other tungaloy products, and I several times tried to get them to articulate what they meant when they talked about wanting to work with me so that I wasn't stiffed with non functional product and out money. They ultimately expressed interest in returning to work on applying the tungaloy drills when the job went back in machines, and then left.
So essentially they offered nothing and wasted my time. The Sandvik 880 is drilling holes twice as fast as the tungaloy drill, with boring process stability. The 880 is not beating up my spindle bearings, turret couplings, and machine. To put the tungaloy product in the machine would be a losing situation. Ild lose money every time a hole was drilled, every time an insert was changed, and would lose production and payroll developing a working feed and speed for the drills. We arent a charity working to support Tungaloy so it doesn't work.
Tungaloy had an opportunity to stand behind the product and opted out.
Indexable insert drills- Sandvik's 880 vs Tungaloy's Tung Twisted TDX
Reply with Quote
