Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Tool cost is often used as the major criterion for justifying tool selection. Ei

ID: 2994405 • Letter: T

Question

Tool cost is often used as the major criterion for justifying tool selection. Either Silicon nitride (SiN)or PCBN  insert tips can be used to machine (bore) cylinder block on a transfer line at a rate of 312,000 parts/yr (Material: gray cast iron). The operation requires 12 inserts (2 per tool) as six bores are machined simultaneously. The machine was run at 2600 sfpm with a feed of 0.014 in at 0.005 in. DOC for finishing. Here are some additional Data:

                                                                                     SiN                                    PCBN

Insert tips/part                                                           12                                         12

Tool life (Parts per tool)                                           200                                     4700

Cost per Tip                                                               $1.25                                 $28.50

a. What is the tool material that you would recommend?

b. on what basis?

Explanation / Answer

for 200 hrs ......... SiN .. $1.25
for 200 Hrs .. PCBN ..... 28.5*200/4700 .. $1.212


so PCBN is recommended , as it is costing lesser


thnx