Practical knowledge, theories and problems related to machining or metal cutting can be found here. Details of operations like turning, facing, threading, drilling, reaming, milling, shaping, knurling, hobbing, etc.
Question: In an orthogonal cutting operation shear angle = 11.31°, cutting force = 900 N and thrust force = 810 N. What will be the shear force? [ESE 2014] Solution: With the help of Merchant Circle Diagram (MCD), this problem can be solved easily. A typical MCD for positive rake angle is shown below. Here in the question, the main cutting force (PZ) and thrust force (PXY) for an orthogonal
Question: Mild steel is being machined at a cutting speed of 200 m/min with a tool rake angle of 10°. The width of cut and uncut thickness are 2 mm and 0.2 mm, respectively. If the average value of co‐efficient of friction between the tool and the chip is 0.5 and the shear stress of the work material is 400 N/mm2, then determine: [ESE 2005] (i) The shear angle (ii)
Question: In an orthogonal cutting test, the cutting force and thrust force were observed to be 1000 N and 500 N, respectively. If the rake angle of tool is zero, what will be the coefficient of friction in chip‐tool interface? [ESE 2000] Solution: For an orthogonal machining, the rake angle of the cutting tool is given as zero. The cutting force and thrust force values are also given. Using these
Question: In an orthogonal cutting process the tool used has rake angle of zero degree. The measured cutting force and thrust force are 500 N and 250 N, respectively. What is the coefficient of friction between the tool and the chip? [GATE 2016] Solution: This problem can be solved with the help of Merchant Circle Diagram (MCD). MCD is the graphical representation of various forces associated with an orthogonal machining
Question: While turning a 60 mm diameter bar, it was observed that the tangential cutting force was 3000 N and the feed force was 1200 N. If the tool rake angle is 32°, then calculate the coefficient of friction. [ESE 2018] Solution: This problem can be solved with the help of Merchant Circle Diagram (MCD). In orthogonal machining of ductile material with a single point turning tool, the relevant forces
Question: In orthogonal cutting test, the main cutting force = 900 N, the thrust force = 600 N and chip shear angle is 30°. Calculate the chip shear force. [ESE 2003] Solution: This problem on cutting force can be solved with the help of Merchant Circle Diagram (MCD). MCD is one vector representation of several cutting forces associated with orthogonal machining with a sharp tool. A typical MCD for positive
Question: The following data from the orthogonal cutting test is available. Rake angle = +10°; Chip thickness ratio = 0.35; Uncut chip thickness = 0.51 mm; Width of cut = 3 mm; Yield shear stress of work material = 285 N/mm2; Mean friction co‐efficient on tool face = 0.65. Determine the following forces: [ESE 2000] Main cutting force Radial force Normal force on tool Shear force Solution: Force calculation in
Question: A single point cutting tool with 0° rake angle is used in an orthogonal machining process. At a cutting speed of 180 m/min, the resultant thrust force is 490 N. If the coefficient of friction between the tool and the chip is 0.7, then calculate the power consumption for the machining operation. [GATE 2015] Solution: Cutting power consumption in orthogonal machining can be estimated from main cutting force (PZ),
Question: In orthogonal turning of a bar of 100 mm diameter with a feed of 0.25 mm/rev, depth of cut of 4 mm and cutting velocity of 90 m/min, it is observed that the main (tangential) cutting force is perpendicular to friction force acting at the chip‐tool interface. The main (tangential) cutting force is 1500 N. (i) Determine the orthogonal rake angle of the cutting tool. (ii) Determine the normal
Question: The Merchant circle diagram showing various forces associated with a cutting process using a wedge-shaped tool is given in the adjacent Figure. The coefficient of friction can be estimated from the ratio: [GATE 2017] (i) f1 / f2 (ii) f3 / f4 (iii) f5 / f6 (iv) f6 / f5 Solution: Merchant Circle Diagram (MCD) is the graphical representation of various forces associated with an orthogonal machining operation. It
