Key Points:

Model: BT40 ER20
Type: BT40 ER20 Collet Chuck Holder
Gage Length: 2.75"

DRAW BAR THREADS: M16×2

Compatible Devices: Milling Machine
Clamping Range: Approx. 1 ~ 13mm / 0 ~ 0.5in (ER20)
Length: Approx. 70mm / 2.8in
Material: 40cr

Key Features:

Dynamically balanced to 20,000RPM at G2.5 by balancing machine at all location for consistent balance.

Made of Superior Alloy Steel ,body and nut select Forging Parts, high precision and long life. Hardened to HRC 56-60. Cryogenic treatment.

Taper ground ≤ AT3 or better accuracy standard for maximum contact with spindle. All critical surface are precision ground.

T.I.R..0001". Concentricity is less than 0.0001" from taper O.D. to collet pocket I.D. Each holder comes with a lab certificate on its taper accuracy and runout measurement on its taper accuracy and runout measurement.

The thread select grinding process to obtain the better interchangeability.

Internal set screw is included and can be used as a stopping pin to prevent end mill or drill from sliding backwards while performing heavy cutting.

Coolant through capability by removing the internal set screw.

Please check product compatibility carefully to ensure it is the product you need.
So as not to waste your time and energy on return.

Details:
Compressive material: Made of 40cr alloy steel material, withstand pressure and explosion.

Strict quality control and quality assurance, high safety factor, can be used with peace of mind.

Application: Suitable for ER20‑A chuck, make choice according to your needs.

Elegant : Great workmanship, replacement for the old one.

Size: Small size, easy to carry and store, convenient to use and with good performance. 

Package Including:
1PC BT40 ER20 2.75" Gage Length Collet Chuck Holder
as the picture