1. In the machinery industry, “one millimeter” is a remarkably large scale—indeed, it’s a significant benchmark across the entire manufacturing sector. So the next time you see a TV ad boasting something like “accurate to the millimeter,” feel free to translate it automatically as: “Our marketing department sure has a vivid imagination.”
2. “Automation” is not the same as “robotization”; only a small portion of automated production lines actually employ robots. Why? Because it’s simply not necessary.
3. Robots are rarely used directly in machining operations, particularly metal cutting. This is because the reaction forces generated during metal cutting can easily bend or even snap most robotic arms—except for delicate tasks like deburring.
4. Chrome plating (ge)—mechanical engineering students generally know it’s pronounced du’ge, because the pinyin for du’luo can’t be entered on a keyboard. However, in everyday usage it’s still pronounced du’luo, since it’s important to distinguish between chromium and cadmium.
5. Quenching is commonly referred to in the industry as “dipping in fire” to distinguish it from annealing.
6. Over the past two years, artificial intelligence—often touted as capable of “dominating the world”—has, in practical mass production settings, largely been limited to processing only production data for the time being.
7. 3D printing (rapid prototyping) is a technology that was actually developed more than 30 years ago and later sensationalized by certain self-serving media outlets. At present, the advancement of this technology largely hinges on progress in materials science.
8. It is rare for a machine to operate exactly as designed right out of the factory; in such cases, “on-site commissioning” is required.
9. After working in this field for a long time, you really can tell at a glance—without even using a ruler—what the bolt’s specification and length are, as well as what size wrench to use.
10. The term “guang” refers to “jing” and “the final pass.” For example, “guang dao” means “the finishing turning tool,” and “guang yi dao” means “the final pass in finishing turning.” The scope of “guang yixia” is quite broad, encompassing processes such as “precision grinding,” “precision milling,” and “precision turning,” all of which generally denote the final operation requiring high precision. “Guang huo” refers to the final finishing of a workpiece surface to enhance its smoothness and surface finish.
11. The terms for rough machining differ between the north and the south: in the south it’s called “kai cu,” while in Northeast China it’s referred to as “la huang.”
12. Threading and buttoning: turning threads.
13. Tapping: cutting threads on a bolt.
14. Smothering fire: Backfire.
15. Shāo: taper or slope, referring to a workpiece that is wider at one end and narrower at the other; most people mistakenly pronounce it as shāo.
16. Defects: Non-conforming geometric and positional accuracy, such as uneven plates, non-circular discs, rotational runout, and poor coaxiality.
17. Purple (pronounced “shai”): a pigment used by fitters to coat workpiece surfaces to facilitate scribing.
18. Tool wear due to cutting: Due to plastic deformation caused by compressive forces, the cutting edge loses its ability to cut; this typically refers to milling cutters.
19. Tool breakage: the cutting tool cracks or breaks.
20. Knife jam: The cutting tool becomes lodged in the workpiece, causing damage or chipping.
21. “Le”: This refers to high-speed finish machining using carbide cutting tools. Because the cutting action at this stage is essentially extrusion, it is called “le.” In everyday usage, it is typically employed as a verb and should be accompanied by appropriate contextual phrasing; for example: “Use a carbide tool to ‘le’ this part, and it’ll be perfectly smooth in no time.”
22. Road: 0.01 mm, northeast.
23. Silk: 0.01 millimeters, southern region.
24. Units: millimeters; for example, 10 millimeters is referred to as “10 units.” For instance: “There are still 10 units left for this job.”
25. Milling cutter: reamer; though this term seems to be used less often.
26. Air milling cutter: a rotary cutting tool resembling a milling cutter, mounted on an air-powered grinding wheel, used by fitters.
27. Bending ruler: right-angle ruler.
28. Pliers: The term is quite broad and its meaning depends on who you’re talking to and how they interpret it, which often leads to misunderstandings when borrowing tools. For example, “tiger pliers” is just one type; any tool with the character “pliers” in its name counts, but a mechanic’s bench vise doesn’t.
29. Air receiver: an air-pressure vessel that looks somewhat like a gas cylinder.
30. Crank: Any device that is rotated by hand, such as a handwheel.
31. Kilogram wrench: torque wrench.
32. Clamp: a device used to tightly fasten a stack of thin metal plates together; its function is similar to that of a bench vise, and it is shaped like the letter “d,” with a screw running vertically.
33. Insert: chip-breaker groove.
34. Kāi qiào (fourth tone): Sharpen the chipbreaker on the turning tool.
35. “Racing to meet the deadline”: the key lies in the word “racing.” This involves closed-loop servo control with two axes coordinated, manual incremental positioning using both hands, and human-controlled machine tools where operators manually turn the hand wheels to regulate the feed rates of each carriage, enabling the machining of relatively complex geometries. Conventional lathes rely on spatial awareness and comparison with master templates, while milling machines depend on lines scribed by fitters; skilled operators can keep dimensional errors within 20 divisions, and exceptionally proficient mold-milling technicians can even perform 2.5-axis machining.
36. Turning the outer diameter: Turning the outer diameter of a workpiece. Rough-turning the blank’s outer diameter is also referred to as “peeling off the black skin.”
37. End face: turning the end face.
38. Tap and tap screw: tapping with a tap (different pronunciation).
39. The term “bèishāo” must always be pronounced as “péishāo.” “Bèishāo” refers to a heating process in which iron ore is heated to a temperature 200–300°C below its melting point. Through this heating, chemical changes occur in the iron ore while it remains in the solid state, thereby improving its metallurgical properties.
40. The term “leaching” should be pronounced as “qin chu,” not “jin chu.” For example: Using blast furnace slag from a steel plant as the raw material, the acid-leaching and auxiliary-leaching methods were employed to study the leaching rates of iron and aluminum. In fact, leaching is a commonly used process in hydrometallurgy; it is applied in the extraction of iron, copper, zinc, and gold. Generally, experienced professionals in the field do not pronounce it as “jin.”
41. “Cast billet” (pi) is often pronounced as “cast billet” (pei). A “cast bloom” (pei), on the other hand, is the product obtained by casting molten steel from a steelmaking furnace through a continuous caster; it is not a finished product and must still undergo rolling to become steel. Of course, in mainland China, both “cast billet” (pi) and “cast bloom” (pei) are used.
42. The character “轧” (zha) in “steel rolling” should not be pronounced as “pressure” (ya). Those who have not worked in the steel industry may often encounter “轧” in phrases such as “paving the road” (ya ma lu), “rolling” (ya zhi), and “competing with or undermining” (ya zha), but once you enter the metallurgical field, this character must be pronounced as “zha”—for example, in terms like roll, steel rolling, and rolling mill.