Cutting speed and feed
- 1. Cutting Speed and Feed
- 2. Cutting speed Cutting speed for drilling is the rate at which the tool passes over the surface of the metal. i.e how fast the cutting tool is spinning . It is commonly expressed in metres per minute.
- 3. Cutting speeds depend on: The material being cut Condition and strength of the tool and machine Depth of cut Rate of feed Material of which the tool is made Availability of cutting fluid Size of the bit being used
- 4. Cutting speed selection The softer the work material, the faster the recommended cutting speed
- 5. The hardness of the cutting tool material has a great deal to do with the recommended cutting speed. The harder the cutting tool material, the faster the cutting speed. The softer the cutting tool material, the slower the recommended cutting speed
- 6. Calculating cutting speed Given in metres per minute spindle speed of machine (N) and diameter of work must be known S (m/min)= πDN/1000 Where π= 22/7 or 3.142 D= diameter of material N= Spindle speed(rev/min) 47-6
- 7. Spindle Speed The rate at which the spindle rotates. It is commonly expressed in revolution per minute.
- 8. Calculating Spindle speed (rev/min) D xS1000 rev/min π = S (m/min)= cutting speed Where π= 22/7 or 3.142 D= diameter of material N= Spindle speed(rev/min
- 9. Examples Calculate rev/min required to drill a hole 15mm diameter in a piece of machine steel (CS 90) Find the cutting speed of a 10mm diameter drill with a spindle of 178 rev/min.
- 10. 5. Find the cutting speed for: Diameter 9mm. Spindle speed 180rev/min Diameter 6mm. spindle speed 20rev/min Diameter 5mm. spindle speed 160rev/min spindle speed 120 rev/min. Diameter 10mm. 6. Find the spindle speed for: Diameter 16mm. Surface speed 20 m/min Diameter 14mm. Surface speed 30 m/min Diameter 15mm. Surface speed 15 m/min.
- 11. Feed Feed rate is the velocity at which the drill bit is fed, that is, advanced into the work piece.
- 12. Feed rate is dependent on the: Type /size of the tool Surface finish desired Power available at the spindle Rigidity of the machine and tooling setup Strength of the work piece set up Characteristics of the material being cut, chip flow depends on material type and feed rate. Depth of cut