CuZn25Al5Mn4Fe3 Counterbored Bushings for Oven Door Counterbalance Pivots
Specify a graphite-plugged MPKZ / OFP03-style flanged sleeve for the external counterbalance linkage of an industrial oven door. The procurement task is a drawing-matched pivot replacement with cylindrical screw-head recesses. Chamber temperature is not a permissible bearing temperature and must not be used as a product rating.
Review the counterbalance force through the entire opening arc
A counterweighted or spring-assisted door can reverse the load on its pivot as the lever passes through its travel. Supply door mass, lever arms, spring or counterweight force, actuator attachment and the opening sequence. Show the independent door stop and safety restraint. Give radial and axial reactions at the bearing, including the parked door condition.
The requested CuZn25Al5Mn4Fe3 metal body and graphite system must be reviewed together with actual measured or specified pivot temperature, including heat soak after shutdown. A high-tensile brass designation alone does not establish thermal clearance or graphite suitability. Counterbores locate cylindrical fastener heads; their floors, diameters and depths differ from conical MPSZ countersinks.
Application boundaries to confirm
This is not a claim of suitability inside an oven chamber, in flame, or at a stated maximum temperature. Confirm thermal shielding, shaft expansion, dust and cleaning chemicals. A replacement bearing does not certify the door restraint, counterweight or emergency release mechanism.
Dimensions and drawing-based quotation checklist
| Review item | Information required |
|---|---|
| Thermal envelope | Cold/hot pivot temperatures, heat-soak duration, shaft/housing materials and shielding. |
| Counterbalance loads | Door mass, lever geometry, spring force curve or counterweight, travel angle and end-stop arrangement. |
| Counterbored flange | Sleeve dimensions, flange face datum, bolt pattern, recess floor thickness and screw-head clearance. |
| Replacement order | Alloy standard, plug locations, thermal running-clearance requirement, drawing revision and quantity. |
Identify metric or inch units and distinguish worn sample measurements from intended new-part dimensions. Include the mating-part drawing and requested material or dimensional documents; their scope and availability are confirmed with the quotation.
Installation and selection checks
Secure the door and isolate stored energy before disassembly. Check flange-seat squareness and pin alignment; do not pull a misaligned housing into position with the mounting screws. Verify cold movement and the agreed hot operating clearance under a supervised commissioning plan.
Frequently asked questions
Can chamber temperature be used in the enquiry?
Include it as environmental information, but also provide the temperature at the bearing and the heat path. They can be very different.
Can MPKZ replace MPSZ directly?
Not by the model names alone. Cylindrical counterbores and conical countersinks require different screw seats; compare the complete flange drawing.
Does graphite remove the need for start-up lubrication?
Do not assume it. Confirm the supplied graphite system, mating surfaces and commissioning lubrication instructions.
Request a drawing-based replacement quotation
Send the drawing and duty to BONIU, identifying CuZn25Al5Mn4Fe3 high-tensile brass, quantity and revision. Material route, fit, manufacturing feasibility and inspection scope are reviewed before the quotation is confirmed.