Features:

Model: ER20
Precision: <0.012
Material: Spring Steel
Ground Roughness is Ra0.4 Microns, plus overall fine polish
Gripping Range: 1mm, 2mm, 4mm, 5mm, 6mm, 8mm, 10mm, 13mm, 1/2 inch, 1/8 inch

Suitable For: Boring, milling, drilling, tapping, engraving, CNC, spindle machines, and other processing

Features:
1.Durable and practical.
2.Special angled slots increase rigidity.
3.Protects tool holder from contaminants.
4.Better overall balance of tool holder assembly.
5.Use with any standard ER collet chucks for coolant-thru tool applications.