Kennametal BT30 Shrink Tooling

Shrink Tooling

The Concept
Heat shrinking is not a new process in the machine tool industry. However, the concept was only recently implemented as a quick-change toolholding mechanism for clamping cylindrical cutting tools for high-speed machining applications.

The Shrink Fit process begins by applying a quick and precise heat to the holding end of a toolholder. This causes the internal bore, which is slightly smaller than the shank of a cutting tool, to expand, allowing a tool to be inserted. As the toolholder cools, the bore shrinks to create 360° of uniform pressure along the entire length of the bore, resulting in an evenly distributed clamping force that mechanical toolholding cannot beat.

Due to the design, flatted-style, Weldon®, and Whistle Notch™ cutting tool shanks can employ Shrink Fit technology. To gain full benefits of the technology, fully cylindrical tool shanks are recommended. As long as the heating processes are kept within the elastic range of the toolholder material, this clamping operation can be repeated for several thousand cycles.

Shrink Fit Tooling Advantages:

Low runout — cutting tools are gripped 360° along the entire length of the cutting tool shank for an evenly distributed clamping force.
Clamping forces are greater than collets or hydraulic chucks.
During testing, tool material properties break down and shear before slippage occurs.
Slim and short toolholder profile designs are achievable because no moving parts are used.

Well suited for high-speed operations because their symmetry provides the best possible balance.
Sealing stop screws are not required — designed interference between the cutting tool and toolholder forms a seal that enables coolant to flow only through designated passages.

These advantages enable Shrink Fit technology to work at greater speeds and feeds, produce better finishes, deliver increased tool and spindle life, and generate more productivity.

HT (High Torque) Shrink Fit Toolholders

HT Shrink Fit holders have a high interference level that offers 30–50% greater torque than competitive systems. This line is only to be used with carbide tools because of their low thermal expansion coefficient. These toolholders require a machine with at least 10 kW of power to apply heat quick enough to avoid heating the tool.

30–50% higher clamping torque compared to GP line.
Balanceable — fine tune with optional M6 set screws.
Suitable for carbide only, designated by groove in front face (requirements below).
10 kW power or greater Shrink Fit device must be used.

GP (General Purpose) Shrink Fit Toolholders

GP toolholders enable the use of all materials and extensions because they have lower interference levels. Operators should use this style if not generating high cutting forces.

TT GP HPV MM

Product Code	D1	D2	D21	L1	L2	L9	V
BT30HPVTT06075M »	-	21.00	27.00	75.00	53.00	26.00	10.00
BT30HPVTT08075M »	-	21.00	27.00	75.00	53.00	26.00	10.00
BT30HPVTT10075M »	10.00	24.00	31.00	75.00	53.00	31.00	10.00
BT30HPVTT12075M »	12.00	24.00	31.00	75.00	53.00	36.00	10.00
BT30HPVTT14075M »	14.00	27.00	34.00	75.00	53.00	36.00	10.00
BT30HPVTT16075M »	16.00	27.00	34.00	75.00	53.00	39.00	10.00
BT30HPVTT18090M »	18.00	33.00	41.00	90.00	68.00	39.00	10.00
BT30HPVTT20090M »	20.00	33.00	41.00	90.00	68.00	41.00	10.00

TT HT HPV

Product Code	D1	D2	D21	L1	L2	L9	V
BT30HPVTTHT12075M »	12.00	24.00	31.00	75.00	53.00	36.00	10.00
BT30HPVTTHT14075M »	14.00	27.00	34.00	75.00	53.00	36.00	10.00
BT30HPVTTHT16075M »	16.00	27.00	34.00	75.00	53.00	39.00	10.00
BT30HPVTTHT18090M »	18.00	33.00	41.00	90.00	68.00	39.00	10.00
BT30HPVTTHT20090M »	20.00	33.00	41.00	90.00	68.00	41.00	10.00