Graphite Bushings for Injection Molds
Solutions / Injection molds
Graphite bushings for injection molds provide a copper-alloy sliding surface with embedded solid lubricant. BONIU BEARING reviews straight and flanged guide bushings for mold alignment and ejector guidance from your drawing or sample. The choice starts with the guide-pin arrangement, stroke, bearing temperature and required fit.
A mold guide bushing and an injection molding machine toggle bushing have different duties. A guide must control alignment through its stroke; a toggle joint carries oscillating loads in the clamping mechanism. Identify the exact location so a quotation does not confuse these parts.
Application positions and bearing choices
| Position | Product family to review | Critical enquiry details |
|---|---|---|
| Mold guide pillar or leader pin | Graphite-plugged straight or flanged bushing | Pin diameter, housing bore, flange location and alignment requirement |
| Guided ejector assembly | Straight graphite-plugged guide bushing | Stroke, reversal rate, guide-pin spacing and plate alignment |
| Machine toggle-link pivot | Drawing-based graphite-plugged bushing | Oscillation angle, pin load and existing lubrication arrangement |
| Axial sliding contact | Separate thrust washer, where the drawing specifies it | Contact area, axial force and mating-face finish |
Material, fit and operating conditions
For a graphite-plugged mold guide bushing, confirm the copper-alloy grade and solid-lubricant specification separately. High-tensile brass and tin bronze are material families to review, not interchangeable descriptions. Send the actual bearing temperature rather than the plastic melt temperature. The guide pin’s hardness, finish and straightness also affect wear.
Assembly requirements
An integral flange locates a bushing, but it does not automatically qualify the flange as an axial bearing face. Define axial duty on the drawing. Treat a change from steel or ball guidance to a bronze guide as an assembly review rather than a dimensional substitution.
Compare the specified alloy with our brass and bronze grade information. Send a required grade or standard explicitly; similar alloy names do not establish automatic equivalence.
Related BONIU BEARING products
Graphite-plugged straight bushings
Solid copper-alloy body with graphite plugs; confirm material and motion duty.
Graphite-plugged flanged bushings
Integral locating flange; confirm radial duty and any separate thrust requirement.
Graphite-plugged thrust washers
Axial sliding face; specify bore, outside diameter, thickness and thrust duty.
What to send for a quotation
- A dimensioned drawing with bore, outside diameter, length, flange and chamfers
- Guide-pin diameter, material, hardness, finish and housing fit
- Travel stroke, cycles per minute, side load and alignment target
- Bearing temperature, contaminants, cleaning agents and lubrication restrictions
- Quantity, drawing revision and any first-article inspection requirement
We review drawings or samples before confirming material, dimensions, availability and lead time. Agree first-article and inspection requirements at the enquiry stage so both sides use the same acceptance criteria.
Frequently asked questions
Can you make a self-lubricating ejector guide bushing from a drawing?
Yes. We review drawing-based and sample-based enquiries, including guide geometry, material and inspection requirements. Dimensions and operating duty are confirmed before quotation.
Do graphite-plugged mold bushings need grease?
The plugs supply a solid lubricant, but installation and supplementary lubrication must follow the selected material instructions. Do not add an arbitrary grease or assume every plug formulation behaves the same way.
Can you match another supplier’s guide-bushing size?
Send the drawing or a complete dimensional specification. Matching nominal size alone does not establish matching fit, material or service performance.
Further selection guidance
Read the related technical guide or explore all bushing selection guides.
Industry reference: OILES: Molding machines and die components. This reference provides application context; its branded material specifications, certifications and performance claims are not specifications for BONIU BEARING products.