Thread Milling Product Catalog

THREADING

Thread Mill Troubleshooting Guide

Problem

Causes

Causes

Thread mill is showing accelerated or excessive wear

Cutting edges are chipping

Thread mill is breaking in the first hole of part Thread mill is creating excessive chatter Out of round thread is produced

Bell-mouthed thread form (small at bottom, big at top) Part rejection because of rough flank finish

Steps in thread profile

Gauge difference from part to part

Machine not making correct

paths to create thread profile Control not accepting the program

1

1

Incorrect tool selection

2, 3 2, 3

2, 3

2, 3

Incorrect speed and feed selection

Catalog

5

RPM too high RPM too low

4

4

4

5, 19

Machine tool specifications restrict RPMs

7

7

7

7

7

Feed rate too high Feed rate too low

6

Incorrect adjusted feed rate adjustment ratio Machine tool specification restricts feed rate Ramp-in is programmed as an axial move Thread mill moved or slipped in its holding device Tool is sticking out of the holder too far Runout between thread mill and holder Incorrect coating creating built-up edge

12

Speed and Feed

7, 19

20

20

13 13 13 13

13 13

15 15 15 15

15 15 15

10

10

8, 17

8, 17

Tool

9

9

Helix angle too low

11 11

Excessive thread mill wear

7, 11, 14

7, 11, 14

Excessive tool pressure

16 16 16 16

16

16

Workpiece moving in its fixturing Insufficient coolant pressure or flow

17 17 16 16

16

16 16

Lack of machine rigidity Incorrect number of passes Incorrect program variables

Machine

22

22

18, 26

18, 26

Did not account for X/Y radial moves for tapered threads Incorrect cutter compensation variables Helical interpolation option not on machine or turned off Machine tool control is not formatted to standard EIA/ASCII/ISO Code

24, 26

23, 26

23, 26

21, 26 21, 26

Programming

25, 26

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