Description:
Centring bush, grade II, for mechanical locating and clamping system.

Material:
Ball bearing steel.

Version:
Hardened and black oxidised.

Application / Accuracy:
- Centring bushes are pressed into the receiver holes of tooling plates using light pressure.
- Two grade I centring bushes with centre distance tolerance +/-0.005 mm permit repeat accuracy +/-0.013 mm.
- One grade I and one grade II centring bush with centre distance tolerance +/-0.03 mm permit repeat accuracy 0.04 mm.

Dimensions / Variant Data:
- Tolerance grade: II.
- T tolerance: +0.025 to +0.050 mm.
- D: 13 mm.
- D1: 19.04 mm.
- L: 20 mm.
- Bore size for centring bush Dia. +0.01: 19.016 mm.

System Information:
- Mechanical locating and clamping system enables base and tooling plates to be precisely positioned and fastened in a few seconds.
- System consists of a locating cylinder, centring bush and receiver bush.
- Recommended sequence: mount two receiver bushes on the machine table/base plate and two centring bushes on the clamping plate; insert locating cylinders through the centring bushes into the receiver bushes; turn the set screws in the locating cylinders approximately two rotations to clamp.
- A grade I centring bush and a grade I or grade II centring bush should be installed as far apart as possible in each fastening plate; more than two positioning points do not improve positioning accuracy.
- When more than two locating cylinders are used for additional holding force, the additional holes in the fastening plate should be 0.4-0.8 mm larger than the selected locating-cylinder diameter.
- With centre distance tolerance +/-0.005 mm and two grade I centring bushes, repeat accuracy within +/-0.013 mm can be achieved.
- With centre distance tolerance +/-0.03 mm and one grade I plus one grade II centring bush, repeat accuracy within +/-0.04 mm can be achieved.
- Grade II centring bushes have a larger internal diameter to accommodate the larger centre-distance tolerance.