Mogul barsFor ID boring operations| Swiss CNC Lathes

Solves common issues associated with ID boring operations

Highly rigid bars and inserts that direct chips away from the part

Unique boring bar design greatly improves rigidity combined with chipbreakers that control the direction of the chip evacuation during the boring operation.

Product video


  • Holder designed to ensure rigidity and eliminate vibrations
  • F1, F05, FG chipbreakers developed for blind hole applications to direct chips backward and out of the hole to prevent chip packing
  • Coolant through boring bars to support chip evacuation

Tooling application

Swiss CNC lathes ID boring operations

Chipbreaker control range

Cutting conditions

Scroll the table →

Coated grade Material Operation type Overhang amount Cutting speed (m/min) Feed (mm/rev) DOC (mm)
ST4 Stainless ID boring operations
ID boring Back turning
Steel shank ~5D
Carbide shank ~7D
40 - 120 0.02 - 0.2 0.1 - 1.0
QM3 Alloy steel / carbon steel / hardened material 50 - 150
DM4/DT4 Difficult-to-cut material / titanium alloy 30 - 70
TM4/ZM3 Non-ferrous / aluminum / plastic / general purpose 50 - 200

Toolholder overhang

[ Cutting conditions ]
Material : Alloy steel・Stainless steel  vc = 80m/min  f=0.05-0.1mm/rev  ap=0.1-0.5mm  WET

Evacuates chips Backwards

F style chipbreakers direct chips backward and out of the hole
* Use a right-handed style insert with a right-handed boring bar

Features of FG / F05 / F1 chipbreakers

[ Cutting conditions ]
Material : SCM415  part diameter φ12  Machining depth 20mm  vc = 80m/min  WET(External coolant)
[ Tools used ]
Holder : Steel shank S10KSTUPR11D12-OH  Insert : TPGH110304 Type
*When using FG, F1, F05 chipbreakers - use a right-handed insert with a right-handed boring bar.

Chip control

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[ Cutting conditions ]
Material : SCM435  vc = 80m/min  f = 0.05㎜/rev  ap = 0.25㎜  part diameter : φ10  External coolant  Toolholder overhang amount : L/D = 4  Machining depth : 20㎜
[ Tools used ]
Holder : S08H-STUPR09D10-OH type (minimum bore diameter of φ10)  Shank diameter : φ8  Insert : TPGH090204 Type

Case study

Valve parts
Material :
Cutting speed :
80 m/min
Feed :
0.05 mm/rev
0.2 ~ 0.5 mm
Holder :
Insert :
Mogul bars
+TM4 FGbreaker

1,500 pcs

Competitor’s product

700 pcs

Competitor's tool life was not stable due to chip packing.
NTK's mogul bar and insert with FG chipbreaker evacuated the chip from the hole resulting in a 2.1 x increase in tool life.

Material :
Cutting speed :
75 m/min
Feed :
0.05 mm/rev
0.1 mm
Holder :
Insert :
Mogul bars
+TM4 F1breaker

900 pcs

Conventional tool

500 pcs

The competitor's boring bar experienced a heavy amount of vibration due to extended overhang.
NTK's boring bar eliminated vibration issues and insert with F1 chipbreaker achieved 1.8 x more tool life.

Tool lineup

Please check product catalog for tooling lineup