Originally Posted by overbored
I am trying to under stand how adding labor rates will make it seem cheaper. labor rate to machine Ti are higher. tool costs are higher and polishing costs are higher. if you are talking about 1/2" thick 316 Vs 1/4" thick Ti then maybe a bit less to cut and drill but most shops have a higher rate when working with Ti. if they make a mistake it gets expensive real fast. it is no doubt Ti is a great material and I have made many part out of it, but while owning a machine shop for the last 37 years I have never found a reason to use it because it is the cheaper way to go. I am still hoping that day will come.
Part of our advantage in labor/tool rates is that all we do is work in titanium. So every tool is specced and purchased for titanium applications. So we are more efficient than other shops when using it. In addition, because we fabricate so many parts in titanium, we have economies of scale that have allowed us to buy the most efficient tools. As an example, we have a very expensive 3D printer to make casting molds. While it was a huge initial investment, now that we own it, we can make new casting molds for around 10% of the cost of traditional mold making methods. Which allows us to cast parts that previously had to be machined. To solve the problem with casting imperfections, we have also acquired a HIPPING machine that allows us to make cast parts with the same strength as machined parts.
This machinery however isn't likely to be found, or available in a standard machine shop.
There is also the fact that with titanium there are no post fabrication processes that are needed. So we don't have to electropolish our parts like a high quality 316L chainplate should be. And unless the customer wants it done for esthetic reasons we don't have to polish at all. Often leaving the parts either a mill finish, or a rough sandblasted finish since the finish of titanium has nothing to do with its corrosion resistance.
While it is rare for the switch to titanium to be less costly, I have seen it happen. So far only in places where the part it is replacing has large corrosion allowances,and needs to be strong. As an example, keel bolts are one of the better places to look. Because ether are so critical, and so corrosion prone the standard is to design keel bolts with a 50% corrosion allowance on top of the 10:1 safety allowance. So if the engineering says a keel bolt needs to have a minimum strength of 5,000lbs, then the safety factor requires a 50,000lbs bolt, and the corrosion allowance kicks that up to 100,000lb bolt.
If we are working in 316 stainless steel this is going to require a 2" keel bolt for a designed load of 5,000lbs
If we are working in G5 titanium, the numbers look a lot better. We still need a bolt rated at 50,000lbs, but since we don't need a corrosion allowance (because in this application titanium doesn't corrode) the bolt can be much weaker and keep the same safety margin. So a G5 titanium bolt rated to 50,000lbs would need to be 13/16" instead of the 2" 316 bolt.
When you price 2" 316 bolts, then price 13/16" G5 bolts, the titanium can actually be less expensive. Particularly if you factor in things like shipping costs. If we wanted to make 5 full J hook poured keel bolts, of say 2 meter each
316 - 2" threaded rod will weigh 71lbs each
g5 - 13/16 threaded rod will weight about 9lbs each
Since we need five, the stainless rod would weigh in at 355lbs, while the titanium would be 45lbs.
Shipping cost for the different pieces... Well the stainless would have to ground shipped by LTL freight, while the titanium could be sent via standard UPS. you could even package them all together as a single shipment.
There is also the labor savings of using lighter and stronger parts. On these bolts it wouldn't matter so much, but if you were replacing the bolts on a much deeper bulb keel, where instead of 2 meter rod you needed 3 meter rod, the weight of the stainless starts getting to the point that you need more than one person to move them increasing labor costs.
Btw I did mention I sell the stuff. I tend to give long explanations, but I hope informative.