Tin-Plated SF-1 PTFE Flanged Bushings for Conveyor Inspection Flaps
Enquire about tin-plated SF-1-F composite bushings for the hinge shafts of a conveyor inspection flap outside the conveyed-product contact zone. The thin-wall split sleeve guides intermittent opening, and the flange provides a defined locating interface. Any moving thrust contact at that flange needs a separate load review.
Separate the composite sliding stack from the tin surface finish
Specify the steel backing, porous sintered bronze intermediate layer and PTFE-based sliding layer as distinct parts of the bearing stack. Confirm the exact layer alloy, lining formulation and thickness on the order; the SF-1 family label does not certify a particular lead content or reproduce another manufacturer's DU formulation. Tin plating is an exterior surface treatment, not the backing material and not the running layer.
Give flap mass, hinge spacing, pin overhang, opening angle and frequency. State whether the flap rests on separate stops or hangs continuously on the hinge. Show the clamping stack so the flange is not trapped against a rotating cheek without axial clearance. PTFE-lined bores require an approved shaft finish and fitted clearance, not a generic bronze-sleeve reaming allowance.
Application boundaries to confirm
Tin plating does not by itself establish chemical resistance, food-contact approval or suitability for repeated pressure washdown. Specify cleaners, humidity and cleaning temperature. Do not machine or ream the thin PTFE surface as a routine fit correction; obtain an approved sizing method for the supplied construction.
Dimensions and drawing-based quotation checklist
| Review item | Information required |
|---|---|
| Flap hinge geometry | Shaft size, bushing OD/length, flange OD/thickness, cheek spacing and allowed end play. |
| Composite specification | Steel backing, sintered bronze layer, PTFE lining specification and exterior tin plating requirement. |
| Operating conditions | Flap weight, support span, angle, cycles, stop loads, cleaner and temperature. |
| Replacement purchase | Housing/shaft tolerances, fitted bore acceptance, seam position, 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
Use clean, chamfered housing entries and supported installation tooling. Protect the split seam, flange and lining from sharp edges. Check installed clearance and free flap travel before reconnecting actuators or safety interlocks; verify those interlocks independently under the machine procedure.
Frequently asked questions
Does tin plating mean a tin-bronze bushing?
No. It describes an exterior coating on a composite construction. The backing and intermediate layer are separate specifications.
Can the bore be reamed if the flap binds?
Do not remove the PTFE lining as a routine remedy. Check alignment, housing size and fitted clearance, then obtain the approved correction.
Is it certified for food-contact conveyors?
No such certification is asserted. This enquiry concerns an external hinge; any regulatory or contact requirement must be reviewed explicitly.
Request a drawing-based replacement quotation
Send the drawing and duty to BONIU, identifying Steel-backed SF-1 PTFE composite with tin-plated exterior, quantity and revision. Material route, fit, manufacturing feasibility and inspection scope are reviewed before the quotation is confirmed.