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Shrink Fit Tool Holders

Two material families covering every scenario: robust alloy steel for heavy cutting, and special stainless steel for the slimmest, longest-life holders on the market.

Two Families

Alloy steel (German style) vs. stainless steel (Japanese style)

Alloy steel holders are produced by major European and American tooling brands. Stainless steel holders use a special martensitic stainless steel — originally developed by MST of Japan — and our dimensions follow the MST standard.

Alloy Steel Type

Material	Special alloy steel
Hardness	HRC 52–54
Heating temperature	450–600 °C
Corrosion resistance	Moderate (maintain regularly)
Heating method	Induction
Profile	Robust — ideal for heavy cutting; heavy-duty type on request
Price	Economical

Stainless Steel Type

Material	Taper: martensitic SS 4Cr13 · Grip: special stainless
Hardness	Taper HRC 52–54 · Grip HRC 40–45
Heating temperature	250–400 °C (safer, no overheat damage)
Service life	≈ 5,000 tool changes
Heating method	Induction or hot-air (universal)
Profile	Slim & CV-curve types, wall from 1.5 mm — deep cavity / 5-axis
Price	Premium (special material)

Shared Specifications

Precision, certified on every holder

◎

Runout ≤ 0.003 mm

Holder length ≤ 100 mm: 0.003 mm · 120 mm: 0.004 mm · 150 mm: 0.005 mm.

≡

Balancing G2.5 @ 25,000 rpm

Higher balancing grades available on request.

⟂

No depth-adjustment screws

Standard versions offer extended gripping depth; slim stainless types start at 3 mm single wall (alloy) / 1.5 mm (stainless).

⚙

Custom options

Balancing adjustment holes and special dimensions available as made-to-order items.

Tool Requirements

Carbide tools only — h4/h6 shank tolerance

Shrink fit works on the thermal expansion difference between holder and tool, so only carbide (tungsten steel) tools with tight shank tolerances can be used. HSS tools expand together with the holder and cannot be removed. Tools must be inserted to the minimum gripping depth or deeper, and must not touch the holder bottom.

Shank Ø (mm)	Tolerance zone	Tolerance (mm)
4	h4	0 / −0.004
5	h5	0 / −0.005
6	h6	0 / −0.008
8	h6	0 / −0.009
10	h6	0 / −0.009
12	h6	0 / −0.011
16	h6	0 / −0.011
20	h6	0 / −0.013
25	h6	0 / −0.013

⚠ Taps often have wider shank tolerance ranges — verify shank tolerance before shrink fitting.

Best Practices

Using & maintaining your holders

Remove coolant tubes (HSK)

Take off rubber-sealed inner-coolant tubes before heating to protect the seals. For BT holders, always use through-hole retention knobs so air can escape.

Clean the bore

Chip residue burns onto the bore at high temperature and corrodes it. Clean with the dedicated bore brush — keep the bore free of chips and oil before every tool change.

Dry & oil after use

Blow the holder dry with air, especially the bore, after water-cooled machining. For storage, remove the tool and apply rust-preventive oil — even stainless types rust without care.

Request the full catalogue & price list

BT30 / BT40 / BT50, HSK63A and more — tell us your taper and tool diameters for a same-week quotation.

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