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 (Metric ver)


  • 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

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Coated grade Material Operation type Overhang amount Cutting speed (SFM) Feed (IPR) DOC (inch)
ST4 Stainless ID boring operations
ID boring Back turning
Steel shank ~5D
Carbide shank ~7D
130 - 600 .0008 - .005 .004 - .080
QM3 Alloy steel / carbon steel / hardened material 150 - 500
DM4/DT4 Difficult-to-cut material / titanium alloy / high temp alloys 130 - 330
TM4/ZM3 Non-ferrous / aluminum / plastic / general purpose 150 - 500

Toolholder overhang

[ Cutting conditions ]
Material : Alloy steel・Stainless steel 260 SFM .002 - .004 IPR .004 - .020 DOC 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 example ]
Material : SCM415 part diameter φ.472" 260 SFM Depth of Bore : .787" Wet
[ Tools used ]
Holder : S10K-STUPR11D12-OH  Insert : TPGH221
*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  270 SFM .002 IPR .010 DOC part diameter:φ.39" External coolant  Toolholder overhang amount : L/D=4  Machining depth : .79"
[ Tools used ]
Holder : S08H-STUPR09D10-OH type (minimum bore diameter of φ.39") Shank diameter : φ.315"  Insert : TPGH090204 Type

Case study

Valve parts
Material :
Cutting speed :
270 SFM
Feed :
.002 IPR
.008 ~ .020 inch
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 :
250 SFM
Feed :
.002 IPR
.0039 inch
Holder :
Insert :
Mogul bars
+TM4 F1breaker

900 pcs

Conventional tool

500 pcs

The competitor's boring bar experienced a heavy amount of vibration occurred 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

View Catalog Information

Please check product catalog for tooling lineup