Copyright Goodheart-Willcox Co., Inc. 476 476 Modern Metalworking Modern Metalworking Summary • Milling machines rotate a multitoothed cutting tool into a workpiece to remove material. • Types of milling machines include fixed-bed fi milling machines and column-and-knee milling machines. • Both fi xed-bed and column-and-knee milling fi machines may have either horizontal or vertical spindles. • The two main categories of milling operations are face milling and peripheral milling. • The two basic methods of milling operations are conventional and climb milling. • Milling cutters are either solid or inserted-tooth cutters. • Commonly used milling cutters include end mills, face mills, and arbor mills. • An arbor is commonly used to hold and drive cutters on horizontal milling machines. • In milling operations, cutting speed refers to the distance (measured in feet or meters) a point (tooth) on the circumference of the cutter moves in one minute. • In milling operations, feed is the rate at which the work moves into the cutter. • Methods of holding work on a milling machine include vises, vacuum systems, magnetic chucks, rotary tables, indexing tables, and dividing heads. • Horizontal and vertical milling machines are capable of performing the following operations: milling fl at surfaces, squaring stock, face milling, fl side milling, gang milling, milling slots or keyways, slitting, milling internal openings, machining multilevel surfaces, drilling, reaming, and boring. • Toolholders with standardized tapers are commonly used to hold cutting tools in vertical milling machines and machining centers. Test Your Knowledge Answer the following questions using the information provided in this chapter. 1. What are the three movements used on a milling machine worktable? 2. The ______ and ______ are the two basic milling machine families. 3. What four basic methods of control are used in milling machines? 4. Name four variations of face milling. 5. Make a sketch showing the difference between conventional milling and climb milling. 6. What are the two basic types of milling cutters? 7. Cutters are also classifi by the methods used to fied mount them in the machine. List them. 8. The ______-flute end mill is used when the cutter fl must be fed into the work like a twist drill. 9. The ______-tooth side milling cutter is used to _ machine deep slots. 10. The plain _____ saw is used for cutoff operations. 11. The slab milling cutter is a member of the ______ milling cutter family. 12. How should you handle milling cutters to prevent hand injuries? 13. In general, the ______ arbor suitable for the job should be used. 14. The ______ goes through the spindle and helps to hold the arbor, collet, or collet holder in the spindle. 15. What three functions do cutting fluids serve? fl 16. To what does cutting speed refer in milling operations? How is it expressed? 17. Calculate the cutting speed (rpm) of a 6″ diameter ″ side mill (HSS) to machine aluminum. 18. Calculate the cutting speed (rpm) of a 1″ diameter ″ end mill (HSS) to machine mild steel. 19. The base on the ______ vise permits the vise to be pivoted to any desired angle. 20. The dividing head is used to ______. A. locate the center of round stock B. divide the circumference of a workpiece into a number of equal parts C. locate hole positions for drilling D. None of the above. 21. Name three types of milling cutters used to machine fl at surfaces. fl 22. The ______ is the most accurate tool to align a vise. 23. Gang milling means ______. A. one cutter is used to do the job B. one or more cutters straddle the job C. machining several work surfaces in one pass using multiple cutters D. the same thing as side milling 24. Explain how to center a side cutter on round stock to machine a keyway using a steel rule and a machinist’s square. 25. Small drills are held in a(n) ______ in the vertical milling machine.