Pipe Threading Machine User Guide – Troubleshooting

Below is a list of possible conditions you may encounter while in search of perfect threads. Under each condition is a list of possible causes that may be responsible for that condition. Clicking on any of the possible causes will direct you to the relative section in the manual which should explain and help you to resolve said threading issue.

Torn Threads

Improper cutting fluid

Poor cutting fluid flow 

Dies are for wrong diameter 

Dies not ground for material being cut 

Dies dull 

Speed too fast 

Material too hard 

Chipped or broken teeth on dies 

On smaller sizes no die bushing 

Starting pressure wrong

Wavy Threads

Dies not ground for material being cut 

Not enough bearing

Dies too tight in die head 

Chattered Threads

Dies dull

Die head slots worn (See also)

Dies need to be stoned (See also)

Dies ground for different material 

Dies resharpened too many times (See also)

Spindle bearings bad 

On larger machines, worn drive gears

Stripping Threads

Dies not in proper slots 

Improper starting pressure

Off Center Threads

Material not cut off properly 

Machine out of alignment (See also)

Material not chucked properly 

Material out of round

Tapered threads on bolt

Improper starting pressure

Die head opening partially during cut 

Dies not free in diehead 

Dies worn

Dies shaving, see stoning

Machine out of alignment (See also)

Inconsistent Size

Die head worn  (See also)

Die head linkage worn (See also)

Variations in material being cut 

On pipe threads operator opening die head too early or too late

Undersized Thread Diameter

Taper Pipe

Adjustable die head set too deep 

Thread too long 

Dies not free in diehead 

Bolt

Adjustable diehead set too deep 

Dies not free in head 

Oversized Thread Diameter

Taper Pipe

Adjustable die head set too shallow 

Thread too short 

Bolts loose in die head 

Die head worn (See also)

Bolt

Adjustable diehead set too shallow 

Thread too short 

Die head worn (See also)

Lead Error on Bolt Threads

Dies need to be stoned (See also)

Dies resharpened too many times (See also)

Inconsistent pressure on carriage (See also)

Reground dies have wrong throat angle 

Taper Changes Over Length of Thread

Die thread length not long enough to generate a full taper pipe thread

Worn spindle bearings 

Screw loose in diehead 

Slots worn in diehead (See also)

Die head opening partially during cut 

Dies not free in diehead 

Worn carriage ways 

Diehead not aligned with material 

Dies Wear Out Quickly

Improper cutting fluid

Speed too fast 

Material extra hard 

Possible damage from regrinding

Dies have been resharpened too many times (See also)

Teeth on Dies Worn Off or Turned Over

Material too hard 

Speed too fast 

Hard spots in material 

Broken die tooth embedded in pipe 

Dies Breaking

Material too hard or tough 

Improper cutting fluid

On smaller diameters use die bushing 

Misalignment of die head 

Die head slots worn (See also)

Defective Dies

Dies Chipping On Teeth

Improper cutting fluid

Material too hard

Poor cutting fluid flow 

On smaller diameters use die bushing

Speed too fast

Die head slots worn or die holders worn (See also)

Dies damaged from being hammered in and out of diehead 

Stopping machine and restarting during cut without opening diehead

Possible damage from regrinding

Dies Chipping in Throat

Pipe chucked improperly 

Pipe seam opened up

Hard spot in material 

Uneven end or torch cut 

Slamming material into dies at start of cut (See also)

Threading roller-cut stainless steel

Chips Fusing to Dies

Improper cutting fluid 

Poor cutting fluid flow 

Speed too fast 

Dies dull 

Dies Difficult to Move in Diehead

Chips in slots of diehead (See also)

Dirt and grit in diehead (See also)

Nicks on sides of dies 

Burrs in diehead slots 

Broken or cracked cam in diehead 

Dies Will Not Start on Material

Adjustable diehead set too small 

Dies not properly seated in diehead 

Machine out of alignment (See also)

Material not gripped properly in chuck jaws 

Chuck jaws worn 

Material oversized 

Material not cut-off properly 

Material too hard 

Machine in reverse

Dies are for left hand threads

Speed too fast

Squealing During Cut

Improper cutting fluid

Poor cutting fluid flow 

Material extra hard 

Dies need to be stoned

Material hanging too far out of chuck

Roller Cutter Wheels Breaking

Improper operator usage 

Pipe too hard 

Roller Cutter Cuts a Spiral

Cutter wheel worn 

Cutter wheel bolt worn 

Cutter assembly mounting bolt worn 

Cutter rollers worn 

Cutter assembly out of alignment with spindle


 

Custom Applications or Technical Questions – Oster is here for you!

When you call Oster Manufacturing there is always a human being on the other end of the line. We have skilled technical and sales experts on hand to take your call. If you’re interested in a machine or tooling for a non-standard threading application we are happy to consult with you on the project and come up with custom engineered solutions to make your project idea a reality. We can make a variety of custom tooling for special projects and keep them in stock for you so you never have to wait when it comes to a difficult project.

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