Issue 3: Inserts Breaking or Wearing Prematurely
Wrong Insert • Change to tougher/higher wear-resistant grade • Use a larger radius if available Excessive Cutting Speed • Reduce speed Inserts Chipping • Check stock allowance and feed rate Coolant Pressure Too Low • Increase through-tool coolant pressure • Adjust the coolant ports of head, if available Excessive Feed Rate • Reduce feed; minimum 25% of insert radius Stock Allowance Excessive • Reset tool for stepped cutting method Low Machine Torque • RPM in area of low spindle torque; increase speed • RPM in area of gear change; decrease speed slightly • Change insert to higher rake angle • Reduce depth of cut Issue 4: Insufficient Machine Power PRO TIP Consult your machine manual to identify where the spindle has the highest torque and adjust the cutting speed at or close to the highest torque area.
Severe Interruption • Decrease speed and feed Chips Packing And Re-Cutting • Check for boring bar/bore diameter clearance PRO TIP Insert grades and coatings go a long way in preventing breaks and premature tool wear. Consider cermet and triple-coated carbide grades for steel. For cast iron, coated carbide grades are best, but Silicon Nitride and some other grades can work in stable conditions.
Excessive Feed Rate • Reduce feed rate as tool exits workpiece material CC Type Insert Holders • Use square insert holders with 6-degree lead Cutting Forces Too High • Reduce depth of cut Issue 5: Excessive Exit Burr PRO TIP SCMT inserts with four cutting edges and a 6-degree negative lead reduce thrust forces upon exit, avoiding the punch-out ring and breakout where the bore ends.
STILL HAVING ROUGH BORING ISSUES? CALL IN THE EXPERTS. 888.866.5776 • bigdaishowa@us.bigdaishowa.com • bigdaishowa.com
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