Optimize boring performance through effective chip evacuation, proper cutting parameters, stable fixturing, and suitable insert geometry. Minimize chatter with Smart Damper technology, correct insert grades, and coolant pressure. Reduce tool wear and breakage by selecting appropriate coatings and inserts while minimizing cutting forces.
ROUGH BORING TROUBLESHOOTING GUIDE Rough boring getting… rough? Keep this cheat sheet handy and be ready when issues arise.
Issue 1: Poor Chip Control or Evacuation Feed Rate too Low • Increase feed rate
Inadequate Space Below Bore • Elevate workpiece from table more
Excessive Height Variation of Inserts • Preset tool to max. .0002" variation of both inserts Excessive Stock Allowance • Consult cutting data tables and/or reset tool for stepped cutting
PRO TIP Consider stepped cutting in boring—in which the insert cutting edges are staggered, both in length and in diameter, effectively creating two tools in one operation. This method produces narrower chips for easier evacuation, especially helpful when dealing with long-chipping, gummy materials like aluminum or mild steels.
Boring Bar Diameter too Large • Reduce to smaller head and extended range holder
Issue 2: Chatter & Vibration
Excessive Speed • Reduce SFM, check cutting data tables Extreme Length/Diameter Ratio • Shorten tool to increase stiffness • Increase boring bar diameter to larger size and use reduction adapters • Change boring head to SMART DAMPER
Insert Radius Too Large • Reduce nose radius of insert Unstable Workpiece • Improve fixture and clamping support Lead Angle On Insert Holders • Change to 90-degree insert holders (type CC)
PRO TIP Deep holes or long-reach applications? Try Smart Damper technology, which damps vibrations and reduces chatter to achieve better surface finishes and improved metal removal rates while allowing for higher cutting parameters.
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
Page 1 Page 2Powered by FlippingBook