CLICK IMAGE TO ENLARGE (+)
Because of its purchase of a new lathe coupled with the implementation of some new CBN inserts for threading, Metalmite is now capable of producing parts in-house that it wasn’t previously equipped to do.
Tom Gendich, president of Metalmite Corp., grew up immersed in a manufacturing environment. His father, Michael Gendich III, who started the business in 1968, saw to it that his son was exposed to manufacturing, so naturally Tom’s earliest memories include deburring parts and sweeping the shop floors. And from early on, Tom was indoctrinated with the unique, forward-looking mentality that his father imbued in the shop.
Michael had originally conceived of Metalmite after a decade of witnessing shop inefficiency in roles as a draftsman, manufacturing salesman and shop manager. He envisioned his own shop as a model of efficiency, based on a dream to create a better approach to manufacturing, tapping into the latest technology for productivity and optimized processes. And Michael continued down that path, growing his company in efficiency and productivity as well as in size and scope.
When Michael eventually retired, Tom was there to take the reins. Having studied in the aviation and management fields he was ready to take over as president. He was committed to keeping his father’s early vision of efficiency and productivity alive. For instance, he studied Lean Manufacturing principles and helped to have the company certified to ISO 9001:2008, as well as getting the company approved as a Prime Contractor for the U.S. Military.
Built on the efficiency principal, while keeping productivity and precision high at the lowest possible cost to the customer, Metalmite thrived and consistently grew over its 45 year history. The shop currently occupies more than 10,000 square-feet of space, and employs 18 operators. The company’s wheelhouse in terms of customers lies primarily in aerospace, military and automotive fields. Though those three industries make up the majority orders, the production mix is ever-changing, keeping things interesting.
“Our unique set of customers keeps us diversified—I have no sales people, our reputation precedes us in a lot of ways,” Tom says. “Most customers have worked with us for 20 to 25 years, and we have strong relationships. And most of the new customers we’ve added have been the result of customers switching to new companies and calling on us to help in their new role.”
The shop predominantly features five- and six-axis turning and milling machines, wire EDM, and CNC grinding machines. Much of the heat treating and finishing is handled by Metalmite, so the company is usually able to deliver a finished product. Taking on turnkey projects is a focus area for the company.
The sweet spot for orders had long been medium-sized runs of around 1,000 parts or less, but with the recent boom in automotive production, Tom has witnessed that run numbers creep upwards of 5,000 specifically for an all-wheel-drive drive shaft. In fact, it was a similar drive shaft that put Tom and shop manager Ryan Matz in a bind that tested Metalmite’s commitment to efficiency and self-reliance in the face of a tight deadline.
Tooling up to Take a Job In-House
A turned drive shaft forgings of 1050 steel, induction hardened to 62 Rockwell, was a difficult-to-machine component. Complicating things, the threaded component featured a milled keyway or slot that interrupted the thread. In fact, there were two keyway slots, one on each side. The slots that made the interrupted cut were 7.6 mm wide and 3 mm deep, so they were deeper than the actual thread. The thread length was 25 mm long, and those keyways went the whole length.
“We had been sending them out for an external thread grinding operation. It became costly and a timing issue – and time is our most valuable resource,” Tom says. “Around the time we were doing that component, we had bought a Samsung SL 35 lathe. We were phasing out an older machine from 1987, and we knew the new Samsung would open the door to a lot of new tooling because of the speeds, feeds and advanced controls. We knew that we’d be able to push the envelope, and start doing our own threading on the hardened steel.”
And for this particular hardened steel job, the thread had a larger flange and needed a drilled hole – the new machine could do the drilling and hold the size they needed. Within a week of purchasing the new machine, Metalmite’s distributor called to invite the shop to the demonstration that Sandvik Coromant was holding on the Samsung SL35 machine. Mr. Matz went to watch, and asked the Sandvik Coromant yellow coat to see some specific threading examples that they could apply to the difficult drive shaft application. Sure enough, the demo produced the results that Metalmite was looking for – Tom and Mr. Matz were ready to take the threading operation in-house.
“When I went to that demo, I wasn’t aware that Sandvik Coromant had CBN for threading,” Mr. Matz says. “I had never seen it before. That was something new that I saw, and it fit the job perfectly.”
Mr. Matz came back from the demo on a Wednesday, and Metalmite was ready to start threading on Thursday. Remarkably, there were only four Sandvik Coromant inserts to our specs in all of North America, so Tom ordered them all –spent $500 for the inserts themselves and had them over-nighted to them, and Sandvik Coromant came through. That was important, as the 120-component run was scheduled for delivery on Monday of the following week.
Hiccups and Heros
Initially, Mr. Matz intended to run at 500 surface feet and 0.003-inch depth of cut. This would place the RPMs at 1,212. But halfway through the first part, the first insert broke. It turns out that somewhere in translation, the keyhole slots hadn’t been taken into consideration.
There they were, Saturday at 10 a.m.; they had just snapped their first insert, and they did not have a part to show for it. At that point, Tom had two options. He could call up the thread grinding shop, begging them to help with the parts Metalmite had promised to the customer for Monday morning, or trust the new technology that Sandvik Coromant had created. He decided to stick with the new technology.
Mr. Matz first thought was the 0.003-inch depth of cut in the interrupted cut was just too much for the insert. On the part he was running, he had already cut the thread. So, in that thread cycle, he couldn’t just back off the feed because the timing wouldn’t pick up, and he’d end up having to scrap the part. He could, however, change the depth. So Ryan reduced the depth of cut by half, which allowed him to cut the rest of the first part. With every adjustment, the tool life improved. But Metalmite was still down to only one insert, five parts into the 120-part run.
That’s when Ryan arrived at to 375 surface feet and 0.001-inch depth of cut, resulting in zero wear on the insert. They were then able to run the remaining 115 of 120 parts on their single remaining insert.
“This is the challenge we face being a job shop: no two jobs are the same. This is why we have to stay up on the latest technology, because if we don't, the industry will pass us by,” Tom says. “Also, this is why we are excited to work with Sandvik Coromant, and look forward to what’s to come in the future.”
Not to mention, when Tom and Mr. Matz were sending these parts out for grinding, they were spending about $17.50 each to get that part ground, a cost that had to be passed on to the customer. By getting the life out of a single insert that they did, for 120 parts, they made out well, even with three out of the four inserts going down early thanks to a simple miscommunication. Once the correct speeds and feeds were dialed in and the keyholes accounted for, that $17.50 per part outsourced went down to about a dollar per component, a significant savings.
“It’s so nice, when you think about it, if you hard turn the whole shaft, you know that the thread is going to be perfect because you’re just finishing on an existing setup,” Ryan says.” You’re hard turning, then threading, and you know you’re running perfect because it’s on the same machine – no removing and then trucking and setting up again on a new machine for grinding. This goes right to the customer, saving on time and preventing unnecessary damage.”
Opening Up New Possibilities
Tom says this one-insert hero story caught everybody’s attention in the shops’ eye, especially since they’ve done a lot of work with competitive tooling companies for many years. Metalmite has been on both sides of the aisle in both making the tooling for Sandvik Coromant’s competitors, and used their tooling. Mr. Matz called all those guys with this problem, but none of them were able to do that kind of threading.
Prior to the new machine and hardened steel interrupted threading operation, the company didn’t use many lathe turning inserts from Sandvik Coromant. Some of the tooling could be found around the shop, but when it came to lathes, Metalmite had been loyal to its suppliers.
“But since then, we have other similar stories on lathes, one was another threading application, one was hard turning with a high micro finish. Sandvik Coromant came through on those, as well,” Tom says. “I also now think there are definitely more applications out there for us and Sandvik Coromant, and our milling department has been watching this whole story unfold. We’re definitely looking at catalogs right now, and I think the doors are opening for more of a larger partnership in the future, now that we know what we can expect.”
Bringing things in-house has been the biggest accomplishment. The company recently began hard turning chrome, a difficult operation that they would usually grind or outsource otherwise. We were able to use an insert and peel off the chrome to the size we needed so Tom bought the tooling and the inserts.
There are other new possibilities as well. The company already does a lot with aluminum, but has recently been asked to look at magnesium. Tom is always monitoring where the larger tooling suppliers are focusing, so non-ferrous is now on the radar, as well. With all of the new possibilities, Tom focuses on tool availability and support.
“Ryan was impressed with the specifics of why the tooling works, but from a management side, the availability of tooling is a key. Many times in the past, we were told about or promised tooling, and it either didn’t exist or took months,” Tom says. “With Sandvik Coromant, we could order it and have it the next day. Something with support, we’d often hear that we could do something with a certain tool or insert, and then it wouldn’t deliver. That wasn’t the case this time. We didn’t even know the product existed, but we’re sure glad we found it.”
Thread whirling attachments installed on this bone screw maker's Swiss screw machines p...