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- Mar 8, 2008
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Hello, I normally don't make definitive statements about things, because it just leads to unnecessary arguments. But in this case I cant open with" in my opinion ". Cast is inferior to forged. It might be good enough in a lot of apps, but when you want better people always go with forged. For instants crankshafts pistons connecting rods. Grain structure is always stronger when forged. Grain size can be fixed after casting by putting the part through heat cycles but strength is increased by forging. Grain size is affected by forging also. If a cast part isn't much cheaper, then in my opinion it isn't a good value. Cast then drop forged is fine.
Grain size isn't so much impacted by casting unless you're not doing any heat treatment afterwards and not managing your mold temperature and cooling process. The main issue is grain flow, which behaves a lot like wood grain, and is completely absent in cast items. However, while forging as a process does eliminate a lot of stages where manufacturing errors can be introduced, modern castings are generally well more than strong enough to withstand use as tools, and the Steel Founders' Society of America even ran a collegiate competition in 2019 where teams competed to produce cast axes that had to chop a steel sheet 3 times and then sever a rope, though most of the teams clearly were not familiar with optimum design specifications for axes.
Casting vs. forging is mostly a strength issue when dealing with MUCH higher forces than those inflicted on hand tools. Good casting process design can eliminate porosity issues from dissolved gasses or mold shrink and yield a tool that would be indistinguishable from a forged one unless doing controlled failure testing into ranges above what a human user could reasonably generate. On paper it's gonna' be one thing, but in use it's another. Casting has been used by custom knifemakers like David Boye and manufacturers like Condor for knives without issue, and there are a lot of cast steel axes out there from various companies that get heavily abused, and I've yet to hear about any of them failing in use due to them being cast vs. forged.
You'll see a lot of smack talk online from forging companies about the disadvantages of casting, but they always portray a "best of forging vs. worst of casting" perspective to make the differences seem more marked than they typically are. There are advantages and disadvantages to either method, but while I'd rather take a forged product over a cast one at equal price point, I have no qualms about using and relying upon a cast tool so long as I know the manufacturer wasn't cutting corners with their process.