MB Expanders: FOUR IMPORTANT MUSTS
- The bore diameter must be within the tolerance shown in Figure 1.
- The bore must be deep enough to accommodate the sleeve entirely.
- The ball must be driven to within .2mm of dimension x in Figure 2, The correct value of x to be obtained from the Product Datasheet. Use the correct Assembly Punch to achieve x. If you do not have this tool, order it now.
- For critical applications each assembly must be pressure tested.
- Do not ream the bore. A rough bore, especially in hard steel, helps the expander to grip better. Best Rz is 10 … 40um. See here.
- Do not force the Expander into the bore by knocking onto the ball. If it does not go in itself, the bore is either too small, has burrs, is not clean or is out of round.
- The MB Expander can be used in a plain bore if at assembly firm support is provided from the opposite side.
- Overall performance is directly dependent on the condition of the bore (e.g. hardness, roughness, edge distance, temperature). Get full information from the Expander Design Guidelines and the KOENIG Technical Documentation. An engineer’s analysis and QA control are recommended.
- Detailed dimensions of the assembly punches are here. Material is toolsteel hardened to 50HRc.
- The ball’s hardness is 45HRc. It can thus be drilled by a carbide drill. Detailed removal instructions are here.