Coventry line
  COVENTRY TOOLS BITS CARBIDE BRAZED TURNING TOOLS
Co 10% SPEZIAL ASP-60 P-20 P-40 K-10 M-10
MATERIAL MANUFACTURING High speed steel 10% Cobalt alloy. First choice quality. High-speed steel cobalt alloy, Tungsten and Carbon High alloy ASP-60 powder metallurgical grade with a more even distribution of cobalt, tungsten and Carbide particles.. Premium carbide imported from Germany and under ISO.
APPLICATIONS Turning, grooving and parting off. General purpose cutting tools. High feed turning. Means cutting depths. High wear resistance cutting edge. Turning and parting off. Turning, grooving, threading. Generalmachining. Turning, grooving, high feed ordificult conditions. Turning, grooving, threading. Generalmachining. Turning, grooving, threading. Generalmachining.
MACHINING Tough materials Wood
Extrusion Shearing tools
Tough materials Wood
Extrusion Shearing tools
Carbon steel, stainless steel,aluminium alloys, heat resistant alloys. First choice grade for general turning steel. Steel machining under difficult conditions.  Aleaciones de cobre a alta temperatura.
Universal grade for cast iron,
aluminium, abrasive materials and copper alloys.
Turning stainless steels and wear resistants manganese steels.
RESISTANCE Allowed in difficult cutting
conditions.
High wear resistance and machining withhigh concentration of heat. Alta resistencia al desgaste.
Alta resistencia de la arista de corte.
High wear resistance.
High strength cutting edge.
High wear resistance. Allowed in difficult cutting
conditions.
High wear resistance. High wear resistance.
REGRINDING Regrinding easily with ceramic or CBN wheels. Regrinding easily with ceramic or CBN wheels. Regrinding easily with ceramic or CBN wheels. Silicon carbide Wheel, finish withdiamond wheel.
SPECIAL FEATURES Good results in wide materials
range.
Better wear resistance at
cutting edge.

Increased productivity by higher cutting conditions and increased wear resistance.
Optimal performance in machining processes
MILLING SOLUTIONS
Problem Cause Solutions
Vibrations on the milling cutter • Cutting speed is too high
• Feed rate is too low
• Tool clamping is not unstable
• Tool is too long
• Tool is too unstable
• Flute length too great
• Reduce cutting speed
• Increase feed rate
• Check the clamping device or replace
• If possible, choose the quickest possible process
• Use a stronger shaft
• If possible, choose the quickest possible process
Vibrations on the workpiece •Clamping is not stable enough • Check tool clamping and optimize if appropriate
Cutter breakage • Tool wear
• Incorrect cutting specifications
• Vibrations
• Conventional milling
• Tool stability
• Workpiece stability
• Replace or re-sharpen tool in good time
• Match cutting specifications to the work
• Reduce rotation speed
• Mill in synchronism
• If possible, choose the quickest possible process
• Check clamping device and optimize if appropriate
Breakage of the cutting edge • Tool stability
• Workpiece stability
• Vibrations
• Feed rate is too high
• Conventional milling
• Cutting material too brittle
• Incorrect tool
• If possible, choose the quickest possible process
• Check clamping device and optimize if necessary
• Reduce rotation speed
• Reduce feed rate
• Mill in synchronism
Milled slot is too small less than the diameter of the tool • Too much tool wear • Replace or re-sharpen tool in good time
Milled slot is too large less than the diameter of the tool • Tool run-out error • Minimize run-out error
Service life is too short • Reaming is too intense
• Incorrect tool chosen
• Incorrect front rake angle
• Lip clearance of the tool is incorrect
• Use a coated tool
• Adjust tool to the work
• Select a tool with the correct front rake angle
• Correctly grind or re-sharpen the tool
Tool breakage • Machining cross-section is too large
• Feed rate is too high
• Tool is too long
• Reduce or adjust feed rate per tooth
• Reduce feed rate
• If possible, choose the quickest possible process
Poor surface quality • Incorrect tool chosen
• Incorrect lubricating coolant delivery
• Feed rate is too high
• Rotation rate too low
• Built-up edge development
• Chip removal not at optimum
• Chips too large
• Tool wear
• Adjust tool to the work
• Ensure correct lubricating coolant delivery
• Reduce feed rate
• Increase rotation speed
• Use tools with a greater twist angle
• Optimize lubricating coolant delivery
• Reduce machining cross-section
• Replace or re-sharpen tool in good time
Chatter marks on the surface • Tool run-out error
• Tool not stable
• Tool clamp unstable
• Reduce run-out error
• Use a tool with a larger shaft
• Check the clamping device or replace
Extreme flank wear • Machining temperature too high
• Incorrect cutting material chosen
• Reduce cutting speed
• Choose a tool made from a suitable cutting material
Too much tool wear • Incorrect cutting specifications
• Incorrect twist angle
• Conventional milling
• Incorrect tool
• Match cutting specifications to the work
• Select a tool with the correct twist angle
• Use tool in synchronism
• Adjust tool to the work
Lengthways markings on the surface • Break-outs at the borehole boundary surface • Replace tool
Extreme crater wear • Cutting pressure too high
• Machining temperature too high
• Reduce feed rate
• Reduce cutting speed
DRILLING SOLUTIONS
Problem Cause Solutions
Borehole is too large • Feed rate is too high
• Chipping blockage
• Run-out defect on the drill used
• Grinds incorrectly
• Reduce feed rate
• Use the correct tool
• Reduce run-out defect as much as possible
• Check grinding is correct
Burr at borehole exit • Cutting speed is too fast
• Wear limit width exceeded
• Reduce feed rate
• Replace or re-sharpen tools in good time
Breakage of the cutting edge • Unstable working conditions
• Incorrect core hole drill
• Unstable workpiece clamping
• Wear limit width exceeded
• Feed rate is too high
• Lip clearance angle too great
• Clear spindle clearance
• Use the correct core hole drill
• Check workpiece clamping
• Replace or re-sharpen tools in good time
• Reduce feed rate
• Carry out better re-sharpening
Fissure in the core • Impact on the chisel edge
• Drill tip too sharp
• Feed rate is too high
• Lip clearance angle too great
• Correct cutting speed
• Re-sharpen correctly
• Reduce feed rate
• Re-sharpen correctly
Chisel edge wear • Cutting speed is too low
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Feed rate is too high
• Correct cutting speed
• Ensure good lubricating coolant delivery
• Ensure good lubricating coolant composition
• Reduce feed rate
Built-up edge development • Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Cutting speed is too low
• Uncoated tool
• Ensure good lubricating coolant delivery
• Ensure good lubricating coolant composition
• Increase cutting speed
• Use a coated tool
Poor borehole surface quality • Feed rate is too low
• Inaccurate positioning
• Increase feed rate
• Centre borehole in advance
Vibrations • Cutting speed is too high
• Feed rate is too low
• Unstable workpiece clamping
• Run-out error of the core hole drill is too great
• Reduce cutting speed
• Increase feed rate
• Ensure stable workpiece clamping
• Reduce run-out error
Flank wear • Cutting speed is too high
• Feed rate is too low
• Clearance angle too small
• Reduce cutting speed
• Increase feed rate
• Increase clearance angle
Corner wear • Excessive speed • Reduce speed to the optimum
• Possible increase in feed rate
Margin wear • Cutting speed is too high
• Run-out error of the core hole drill is too great
• Tool tapering is insufficient
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Reduce cutting speed
• Reduce run-out error
• Use tools that are more tapered
• Ensure good lubricating coolant delivery
• Ensure good lubricating coolant composition
Fluting edge breakage • Poor chip removal
• Drill bit is not stable in the chuck
• Remove earlier
• Ensure that the drill bit is in the chuc
Stand length is insufficient • Incorrect cutting specifications
• Unstable workpiece clamping
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Ensure cutting specifications are correct
• Ensure stable workpiece clamping
• Ensure good lubricating coolant delivery
• Ensure good lubricating coolant composition
Poor borehole surface quality • Feed rate is too low
• Inaccurate positioning
• Increase feed rate
• Centre borehole in advance
Vibrations • Cutting speed is too high
• Feed rate is too low
• Unstable workpiece clamping
• Run-out error of the core hole drill is too great
• Reduce cutting speed
• Increase feed rate
• Ensure stable workpiece clamping
Flank wear • Cutting speed is too high
• Feed rate is too low
• Clearance angle too small
• Reduce cutting speed
• Increase feed rate
• Increase clearance angle
Corner wear • Excessive speed • Reduce speed to the optimum
• Possible increase in feed rate
Margin wear • Cutting speed is too high
• Run-out error of the core hole drill is too great
• Tool tapering is insufficient
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Reduce cutting speed
• Reduce run-out error
• Use tools that are more tapered
• Ensure good lubricating coolant delivery
• Ensure good lubricating coolant composition
Fluting edge breakage • Poor chip removal
• Drill bit is not stable in the chuck
• Remove earlier
• Ensure that the drill bit is in the chuc
Stand length is insufficient • Incorrect cutting specifications
• Unstable workpiece clamping
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Ensure cutting specifications are correct
• Ensure stable workpiece clamping
• Ensure good lubricating coolant delivery
• Ensure good lubricating coolant composition
THREADING SOLUTIONS 
Problem Cause Solutions
Thread cutting • Incorrect thread cutter
• Incorrect tolerance
• Thread cutter is not centered
• Cutting speed is too high
• Insufficient lubricating coolant delivery
• Core hole bore is too small
• Chipping blockage
• Incorrect axial feed rate selected
• Match the thread cutter to the correct material group
• Check the tolerance of the thread cutter and, if applicable, use another tool
• Check tool mount and position the center of the thread cutter over the hole
• Reduce cutting speed
• Ensure good lubricating coolant delivery
• Ensure that the correct core hole bore is used (see core hole drill table)
• Use the correct tool shape
• Reduce feed rate to 5-10% and check the contact pressure of the thread cutter
Thread is too narrow • Incorrect thread cutter
• Incorrect tolerance
• Core hole bore is too small
• Thread is too narrow
• Match the thread cutter to the correct material group
• Check the tolerance of the thread cutter and, if applicable, use another tool
• Ensure that the correct core hole bore is used (see core hole drill table)
• Ensure that the correct tool shape is used
Too much wear • Incorrect thread cutter
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Cutting speed is too high
• Match the thread cutter to the correct material group and select the correct shape
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
• Reduce cutting speed
Tool chipping off • Incorrect thread cutter
• Hardened surface
• Core hole bore is too narrow
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Match the thread cutter to the correct material group and select the correct shape
• Reduce speed, choose a coated tool,
• Ensure good lubricating coolant composition
• Ensure that the correct core hole bore is used (see core hole drill table)
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
Thread surface is not clean • Chipping blockage
• Cold welding on the thread cutter flank
• Unsuitable tool shape
• Cutting speed is too high
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Ensure that the correct tool shape is used
• Remove cold welding or use another tool
• Ensure the correct thread cutter is used
• Reduce cutting speed
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
Thread cutter breakage • Chip blockage or jam
• Tool shape unsuitable for the work
• Too much wear on the thread cutter
• Torque is too high
• Thread core hole is too narrow
• Adapt choice of thread cutter to the work being carried out
• Ensure that the correct tool shape is used
• Replace the thread cutter in good time
• Use a thread cutter with overload coupling
• Ensure that the correct core hole bo
Thread cutter overheating • Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Thread cutter is worn
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
• Replace the thread cutter in good time
Thread axially blended • Obtain left-rotating thread cutter for lower point pressure
• Strong right-rotating thread cutters have point pressure that is too strong
• Keep thread cutter in the same pressure range as the thread cutter chuck. Stronger axial contact pressure when beginning to cut
• Only minimum contact pressure when beginning to cut
REAMING SOLUTIONS · SOLUCIONES PARA ESCARIADO
Problem Cause Solutions
Diameter is too large • Cutting speed is too high
• Feed rate is too high
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Point is too short or very uneven
• Tool or machine spindle rotation incorrect
• Due to low-density or flexible structure, the working material enlarges
• Reduce cutting speed
• Reduce feed rate
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
• Lengthen point or reduce point angle
• Centrally clamp or guide the reamer. Use a reamer chuck
Diameter is too narrow
 
• Cutting speed is too low
• Feed rate is too low
• Chip removal rate is too low
• Point is too long
• Tool is ground smooth
• The working material is of high density or has an inflexible structure
• Reamer of insufficient size
• Too much heat created when reaming. Contracting borehole
• Tool diameter too small

 
• Increase cutting speed
• Increase feed rate
• Increase machining allowance
• Select a smaller point
• Check the tool and replace in good time
• Increase reamer diameter
• Select a higher allowance
• Increase lubricating coolant delivery
• Select the correct diameter
Heavy wear • Insufficient size • Select a larger diameter
borehole is not round or is conical • Incorrect positioning in the machine spindle
• Alignment error between the tool and the borehole
• Asymmetrical point angle
• Incorrect tool run-out
• Clearance angle too great
• Point is not round
• Insufficient guide
• Check the spindle and correct its position
• Use front-cutting reamers
• Re-sharpen point angle
• Centrally clamp tool, use reamer chuck and guide
• Reduce clearance angle when re-sharpening
• Evenly sharpen and round the point
• Guide more accurately or use guide reamers
Poor surface quality • Worn tool
• Front rake angle is too small
• Cutting speed is too low
• Feed rate is too low
• Workpiece tends to stick (built-up edge)
• Cutting exit is sharp-edged
• Insufficient lubricating coolant delivery
• Incorrect lubricating coolant composition
• Cutting is uneven
• Defective point
• Replace or re-sharpen tool in good time
• Re-sharpen correctly
• Increase cutting speed
• Increase feed rate
• Increase clearance angle and front rake angle; use highly fluid lubricant
• Round and smooth the borehole exit
• Ensure good lubricating coolant delivery
• Ensure correct lubricating coolant composition
• Grind the point and guide piece to an evenly round shape or to a tapered shape
• Finely smooth or lap the point round and smooth the guide piece joint
The tool jams and breaks • Borehole is too narrow
• Bevel width is too great
• Shaft is too short
• Worn tool
• Reduce material cross-section
• Check the tool and replace if necessary
• Check the tool and replace if necessary
• Replace or re-sharpen tool in good time
Borehole exit too narrow • Feed rate when removing the reamer from the borehole is too high • Reduce feed rate shortly before passing through or use even feed rate
Broken off or deformed driver • Incorrect position between shaft and clamping device • Keep shaft and clamping device clean and undamaged