EMUGE Taps are very free cutting and will easily cut oversize threads if overfed or pushed. For the best results, we recommend the use of an EMUGE Quick-Change Tap Holder with built-in tension, compression and overload clutch features. Always utilize your holder's tension feature by programming spindle feed to 95-98% of the calculated feed rate.

Possible Cause	Possible Remedy
Problem: Tapping oversized threads (no-go gage too loose)
Improper tap for material and thread application.	· Use a suitable tap for the hole style and material being tapped. Reference the EMUGE Tap Finder for proper selection.
Cutting speed to high.	· Reduce cutting speed. · Improve coolant/lubrication.
Cold welding on the flanks of the tap (loading).	· Use a new tool. · Use surface treated taps. · Improve coolant/lubrication. · Grind away chipped and damaged teeth.
Chip packing in flutes.	· Use tap with different flute geometry/angle. · Possibly use set of taps.
Grinding burr.	· Remove burr with soft wire or fiber brush.
Incorrect fixturing or positioning of part.	· Use tap holders with axial and parallel floating. · Check clamping of part for correct alignment.
Inconsistent feed of tap.	· Tap with controlled feed. · Check CNC programs. · Check lead screw for backlash. · Use compensating tension/compression tap holder.

Problem: Tapping oversized threads (no-go gage loose)
Possible Cause	Possible Remedy
Tap selected too large for class of thread fit required.	· Review markings on tap and determine if it is suitable for the class of fit required. · If in doubt, contact an EMUGE Representative.
Improper reconditioning of tap.	· Reconditioning of tap requires that all ground surfaces maintain the original geometry put on by the manufacturer. · Contact an EMUGE Representative for instructive information.

Problem: Tapping bellmouthed hole (first few threads gage oversize)
Possible Cause	Possible Remedy
Wrong initial starting pressure.	· Work with controlled tap feed.
Axially hard working spindle.	· Use a tap holder with length compensation.
Incorrect fixturing or positioning of part.	· Use a tap holder with axial and parallel floating. · Check clamping of part for correct alignment.

Problem: Torn and rough threads
Possible Cause	Possible Remedy
Improper selection of tap for material and thread application.	· Use a suitable tap for the hole style and material being tapped. Reference the EMUGE Tap Finder for proper selection.
Cutting speed too fast or slow.	· Select proper cutting speed. · Improve coolant selection to assist the effects of tap speed.
Cold welding on the flanks of the tap (loading).	· Use a new tool. · Use surface treated taps. · Improve coolant/ lubrication. · Find away chipped and damaged teeth.
Chips packing in flutes.	· Use tap with different flute geometry/angle. · Use set of taps.
Grinding burr.	· Remove burr with soft wire or brush.
Tap drill too small.	· Use correct size drill. · Reference recommended sizes listed in EMUGE catalog. Note that cutting and roll form taps use different size tap drills for the same size thread. · If in doubt, contact an EMUGE Representative.
Insufficient coolant/ lubrication.	· Selection of suitable coolant/lubrication for material being tapped. · Use adequate amounts of coolant lubrication.
Tool overloading due to coarse pitch, hard materials or short chamfers.	· Use a set of taps.

Problem: Tapping undersized threads (go gage won't enter/binds up part way into hole)
Possible Cause	Possible Remedy
Tap selected too small to do multiple regrinds.	· Limit the number of regrinds a tap has. · Use a new tap.
Area of wear not removed when tap was resharpened.	· Grind tap again. · Use a new tap.
Improper tap for material and thread application.	· Use suitable tap for the hole style and material being tapped. · Reference the EMUGE Tap Finder for proper selection.
Go gage binds up part way into hole.	· Tap is dull - recondition or replace tap. · Avoid too much axial force during tapping operation (this caused the tap to cut out of lead) · Use tap holders with length compensation.
Tap selected too small for class of thread fit required.	· Review markings on tap and determine if it is suitable for class of fit required. · If in doubt, contact an EMUGE Representative.

Problem: Tap life too low
Possible Cause	Possible Remedy
All reasons stated in torn and rough threads.	· See torn and rough threads.
Loss of tap hardness by excess hear during regrinding.	· Change the specification of the grinding wheel. · Use coolant while grinding.
Loss of surface treatment from regrinding.	· Retreatment of the tap surface. · Check suitability of surface treatment for material being tapped.
Work hardened drill hole and hole chamfer.	· Change or regrind tap drill more frequently. · Check proper drilling speed and feed. · Anneal part before tapping.

Problem: Torn and rough threads
Possible Cause	Possible Remedy
Improper selection of tap for material and threading application.	· Use a suitable tap for the hole style and material being tapped. · Reference the EMUGE Tap Finder for proper selection.
Tap drill too small.	· Use correct size drill. Recommended size drills listed in EMUGE catalog. Note that cutting and roll form taps use different size tap drills for same size thread. · If in doubt, contact an EMUGE Representative.
Tap hole not deep enough.	· Check actual drill depth, drill may have slipped back into holder.
Missing tap drill hole.	· Ensure tap drill hole is present. Common problem in multiple spindle applications on transfer lines.
Chips packing in flutes.	· Use tap with different flute geometry/angle. · Use a set of taps.
Cutting speed too high or low.	· Select proper cutting speed. · Improve coolant/lubrication to assist the effects of the tap speed.
Cold welding on the flanks of the tap (loading).	· Use a new tool. · Use surface treated taps. · Improve coolant/lubrication. · Grind away chipped and damaged teeth.
Overload of the chamfer teeth.	· Use longer chamfer. · Increase number of tap flutes to provide more chamfered teeth.
Incorrect fixturing or positioning of part.	· Use tap holders with axial/parallel floating. · Check clamping of part for correct alignment.
Tap hitting the bottom of hole.	· Use tap holder with length compensation and torque overload system.
Tapping hard or high tensile materials.	· Check selection of tap, carbide tap may be more suitable then high speed steel taps.