Learn about how a quill stem is made - here is a great example. Cinelli Road Stems - the CINELLI 1A ROAD STEM - made in Italy, the Cinelli 1A stem is one the most widely recognized road quill stems ever made. At the time of it's original release, it represented a major improvement in the overall quality that cyclists could expect from bike stem manufacturers. This quill stem is forged from aluminum in a single solid forging, and then it's machined and polished. The quill is bored from the bottom to a depth of 115mm, leaving a wall thickness of 4.5mm for the section of quill stem that is exposed just above the headset. At the base of the interior the hole flares from the 4.5mm thickness down to 1.8mm thick. This reduction in wall thickness is to permit the quill stem wedge to push strongly against the steerer tube. 27 millimeters from the bottom, a 4mm hole is drilled front to back through the quill. The quill stem is then sawn from the bottom straight up to each of these holes leaving a 3mm kerf. This cut creates essentially two "legs" so that the wedge splays as it's threaded up the expander bolt, and it is these "legs" that press against the steerer tube, holding the quill stem firmly in place. The quill is bored from the top with a 12mm hole, that creates the cradle that supports the expander bolt head, leaving it flush with top of the stem. The binder is drilled through with the characteristic 26.4mm diameter hole for the handlebar. Cinelli bars have always had a slip-sleeve on the center of their bars, building the outer dimension to 26.4mm. The front of the binder is drilled through for the binder bolt, leaving an extra recess for the for the bolt head to fit elegantly into. There is a second drilling from the front to create a small notch, that a "key" on the bolt head sits into, preventing it from rotating as the rear nut is tightened. The bottom of the binder is then cut through leaving a 3mm kerf that creates the cinch system. The final stage of aluminum work is the immaculate polish done to clean all external forging marks, producing a smooth pearl-like satin finish on the quill stem. One of the differences of this Cinelli quill stem was the "hidden binder bolt". Up to this time it had been acceptable to leave the hex head on the bolt exposed at the front of the stem. Cinelli took a different approach by using a flush faced head on the bolt, with a notched key to hold it in place, as you turned a nut with a hex head from the back of the binder to tighten your bars. This left a very clean and sleek look, and at least in the mindset of the rider, it reduced wind resistance from the quill stem. The bolt brought the simple elegance to their quill stem design, and elevated the art of stem making. The binder bolt and nut are made of chrome plated steel, because the nut would rotate against aluminum. Cinelli inserts a thin brass washer between the nut and the stem, providing a lubricated surface for the nut to slide on. The binder bolt, nut and washer weigh 14 grams. The expander bolt is made of chrome plated steel, with 7mm x 1mm pitched threads, a 135mm length, and has the same thin brass washer where the steel head rotates against it's aluminum seat. The wedge is cast of steel, in a conical shape so that as the wedge is drawn up, it applies sloping even pressure to the bottom of the legs. The expander bolt, wedge and washers weigh 60 grams. The Cinelli 1A is made only in the 1", (22.2mm) diameter, with a -15 degree rise, and comes in 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, and 140mm extension lengths. A Cinelli 1A stem in the 80mm length weighs 258 grams. Lengths 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm.