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Old 06-02-21, 11:41 PM
  #9  
cjenrick
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Who came out with investment cast lugs first, was it Cinelli?

"Traditional stamped lugs (aka pressed lugs) are formed by pressing sheet steel over a mandrel, bending them to shape, and then welding the seams. These lugs are of constant thickness resulting in stress risers, if large amounts of file work are not done to alter the thickness of the lug. They are easily identified by the visible seam.[6]

Lugs used today on higher performance bicycles are investment cast (aka lost wax process). Copies of the lugs are made in wax, and they are attached together into a "tree". The tree is surrounded by ceramic and fired in a kiln, thereby melting the wax and setting the ceramic. Finally, molten steel is poured in to produce the lug. Cast lugs have many advantages over stamped lugs: they allow much finer detail, tighter tolerances (and correspondingly less manipulation and file work), and more accurate angles, and they can be made from superior materials (chromoly or stainless steel). The disadvantages of cast lugs are few: casting doesn't allow for long points or cutouts (done for aesthetic appeal), it is difficult to bend the lug to change the angle (requiring framebuilders to order lug sets that precisely match the desired frame geometry), and they are more expensive."
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