Guide Pillar Shoulder Guide Bush

A bronze-matrix guide bush with graphite solid-lubricant plugs and an integral shoulder (flange) that provides axial location and a thrust face. Built for high-load, low-speed, high-temperature, dusty, or oil-free duty where oiled bearings are impractical.

No lubrication task

Graphite solid-lubricant film runs oil-free, removing the recurring lubrication step in molds, clean rooms, and hard-to-reach pivots

Radial + axial in one part

The integral shoulder locates the bush axially and carries thrust, replacing a separate thrust washer and locating ring.

Hot, dirty, wet duty

Operates dry to roughly 250 °C and tolerates dust, water, and oil-free environments better than oil-filled types.

Fewer assembly parts

One flanged component consolidates guide, stop, and thrust functions in mold/die and machinery sets.

What it is

Definition (citable): A shoulder-type graphite bronze guide bush is a cylindrical bronze bearing with an integral radial flange (the shoulder) and graphite plugs embedded in its bore. The bronze matrix carries the load; the graphite transfers a lubricating film to the shaft, allowing oil-free operation. The shoulder seats in the housing to provide axial location and a thrust bearing face. Typical geometry follows DIN 9834 / ISO 9448 flanged guide-bush standards.

Also referred to as: graphite-plugged bronze bush, oilless (oil-free) guide bush, JDB-type solid-lubricant bearing, flanged graphite bronze guide bushing.

Construction & how it works

Standard: DIN 9834 / ISO 9448. Base alloys: ZCuZn25Al6Fe3Mn3, CuSn10, C95800, C95400. Counterface: ≥ HRC 50, Ra 0.4–0.8 µm. Graphite fill: ~25–30%

guide bush

The bronze matrix

The bearing body is a cast or wrought copper alloy (commonly high-strength brass or tin bronze). It supplies mechanical strength, wear resistance, and thermal conduction. Surface hardness for the high-strength brass grade is typically HB ≥ 210.

guide bush graphite plugged

The graphite plugs

Graphite inserts are pressed or cast into holes across the bearing surface (commonly ~25–30 % of the running area). Under load the graphite shears to form a continuous solid-lubricant film on the shaft, so no oil or grease is needed.

bronze guide pillar bush
guide pillar bush

The shoulder (flange)

  • Axially locates the bush in the housing (seats against a shoulder or clamped face);
  • Provides a thrust bearing face for combined radial + axial loads;
  • Replaces a separate locating ring or thrust washer, reducing part count in mold/die and machinery assemblies.

From component to solution: problems it addresses

The shoulder-type graphite bronze guide bush is specified not only as a replacement part, but as a response to recurring operating problems where oiled or rolling bearings underperform. The table maps typical problems to the mechanism that addresses them.

Operating problem Why oiled / rolling bearings struggle How the oilless shoulder bush responds
Lubrication failure in molds and dies Grease carbonizes under heat and attracts abrasive dust; re-lubrication stops production Graphite supplies a solid film with no oiling task; the shoulder locates ejector and guide pillars without a separate washer
Oil contamination in food, pharma, clean rooms Oil can soil product or breach hygiene rules Oil-free running removes the leakage source; suitable for washdown and sterile lines
High-temperature duty (furnaces, ovens, kilns) Grease and oil lose film above their temperature limit Graphite lubrication remains effective to about 250 °C dry (short excursions higher); verify for continuous service
Dusty or dirty environments (mining, off-highway, cement) Lubricant traps abrasive particles and accelerates wear No oil to attract grit; the bearing tolerates contaminated conditions better than oil-filled types
Corrosive / marine service Standard bronzes and steel corrode in seawater Nickel-aluminum bronze (C95800) and aluminum bronze grades resist seawater and many chemicals
Combined radial + axial load in a compact space Separate bush + thrust washer + locating ring add parts and height The integral shoulder carries thrust and axial location in one part, reducing assembly count
Hard-to-reach pivots (excavator, crane, gate) Re-lubrication is infrequent and labor-intensive No scheduled lubrication task; inspection interval extends versus oiled bearings (verify by duty)
Scope note: The bearings remove the recurring lubrication task and widen the operating envelope in the conditions above; they do not remove all inspection, and the stated temperature / load figures are reference values requiring confirmation against the actual duty and supplier data.

Materials & technical ratings

The values below are reference ranges for graphite-plugged bronze oilless bushes. Actual ratings depend on the base alloy, graphite grade, duty cycle, and shaft condition, and must be confirmed against the supplier’s datasheet and sample testing before design sign-off.

Common base alloys

Grade / reference Alloy (GB / UNS) Typical use Surface hardness
JDB-1 (high-strength brass) ZCuZn25Al6Fe3Mn3 High load, general molds & machinery HB ≥ 210
JDB-2 (tin bronze) CuSn10 / ZCuSn10Pb1 Corrosion resistance, lower load HB ≥ 90
Nickel-aluminum bronze C95800 Seawater / marine service HB ≥ 160
Aluminum bronze CuAl10Fe / C95400 Elevated temperature, wear resistance HB ≥ 170

“JDB” numeric codes are not standardized across suppliers. Specify by base alloy designation, not by code number, when ordering.

Operating ratings (reference)

Parameter Reference range Notes
Allowable dry-service temperature -40 to +250 °C Graphite oxidizes above ~250–300 °C; verify for continuous use
Allowable PV upper limit (graphite) 1.5–3.8 N/mm²·m/s Conservative design ~2.0 with safety factor ≥ 1.5
Allowable static-load upper limit reference ~150 N/mm² Alloy-dependent; confirm with supplier
Allowable dynamic-load upper limit ~40–70 N/mm² Depends on speed and duty cycle
Allowable sliding-speed upper limit (dry) ~2 m/s Higher with assisted lubrication
Coefficient of friction (dry) 0.10–0.20 μ Typical running range
Counterface shaft ≥ HRC 50, Ra 0.4–0.8 µm Hardened, ground steel recommended
Graphite fill ratio ~25–30 % of surface Plug pattern varies by design
Design note: These figures are collated from published oilless-bearing references and are intended as a starting point for selection. They are reference values, not a performance specification. Final sizing must follow the current applicable standard and be validated by sample testing under representative load, speed, and temperature.

Selection comparison

Shoulder (flanged) vs straight guide bush

Aspect Shoulder (flanged) type Straight type
Axial location Provided by flange Needs separate stop / housing shoulder
Thrust load Carried on flange face Not carried; needs thrust washer
Part count One part for radial + axial Radial only
Select when Combined radial + axial, or built-in stop Pure radial guidance

Graphite bronze (oilless) vs other bearings

Aspect Graphite bronze (oilless) Oil-impregnated bronze Rolling bearing
Lubrication None (solid graphite) Oil reservoir Grease / oil
Maintenance Minimal (no lubrication task) Periodic oil Periodic re-lube / seal care
High temp Suited (to ~250 °C) Oil limits temp Grease limits temp
Contamination risk No oil to leak Oil can soil product Sealed types reduce risk
Dusty / dirty Tolerates Clogs pores Needs sealing
Speed Low–moderate Low–moderate High

Your Path to Efficiency: Guide Pillar and Bronze Graphite Bush Offerings

Not sure which type fits your duty?

Send your load, speed, temperature, and environment and we will confirm the shoulder vs straight and alloy choice.

Cheers!

Where it is used

The shoulder type suits high load, low-to-moderate speed, high temperature, dusty, wet, or oil-free duty. It is less suited to continuous high-speed rotation, where oil/film or rolling bearings are typically preferred.

Graphite bronze shoulder guide bush in a plastic injection mold base, guiding the ejector and clamping toggle under high-temperature oilless duty

Molding & dies

  • Mold-base guide pillars and bushings
  • Clamping toggle/link bushings
  • Ejector and stripper-plate guide bushes
  • Slider/cam and wedge guides
Graphite bronze oilless guide bush on a steel continuous-caster guide roll and rolling-mill guide, running in high-temperature metal-processing duty

Metals & heavy industry

  • Continuous-caster guide rolls
  • Rolling-mill guides and furnace-door hinges
  • Kiln and conveyor roller bearings
Excavator and crane pivot fitted with a flanged graphite bronze shoulder guide bush, carrying combined radial and thrust load on off-highway machinery.
Nickel-aluminum bronze shoulder guide bush in a sluice-gate hinge and rudder bearing, resisting seawater corrosion in marine duty.

Construction & off-highway

  • Excavator/crane pivot bushings
  • Hook and sheave shaft bearings
  • Articulation and linkage pins

Water, marine & clean rooms

  • Sluice/gate hinges
  • Rudder and stern-tube bearings
  • Turbine wicket-gate pivots
  • Food, pharma, and packaging (oil-free)

Frequently asked questions

A shoulder-type graphite bronze guide bush is a cylindrical bronze bearing with an integral radial flange (the shoulder). The bronze matrix carries solid-lubricant graphite plugs, so it runs without added oil or grease. The shoulder provides axial location and a thrust bearing face, combining radial guidance and axial load support in one part. It is commonly built to DIN 9834 / ISO 9448 flange-guide-bush geometry.

PV is the product of contact pressure P (N/mm²) and sliding velocity V (m/s). For graphite-plugged bronze oilless bushes, published dry-running PV limits typically fall in the 1.5 to 3.8 N/mm²·m/s band. A conservative design value of about 2.0 N/mm²·m/s with a safety factor of at least 1.5 is widely used. Actual allowable PV depends on the base alloy, graphite type, duty cycle, and shaft condition, and should be confirmed against the supplier’s datasheet and sample testing.

The mating shaft (counterface) is normally specified at a hardness of HRC 50 or above, with a ground surface roughness Ra in the range of 0.4 to 0.8 micrometers. A harder, smoother shaft reduces plug wear and extends service life. Induction-hardened steel shafts are a common choice.

In dry operation, graphite-plugged bronze bushes are generally rated from about -40 °C up to roughly 250 °C; short excursions toward 300 °C may be tolerated depending on the alloy and duty. Above roughly 250 to 300 °C graphite begins to oxidize and its lubricating film degrades, so continuous high-temperature service should be verified. Aluminum bronze and nickel-aluminum bronze are used where higher temperature or corrosive/marine service is expected.

Choose the shoulder (flanged) type when the application needs both radial guidance and an axial stop or thrust load in one component. The flange seats against a shoulder in the housing and provides a thrust face, removing the need for a separate locating ring or thrust washer. For pure radial guidance with no axial load, a straight bush is simpler and often sufficient. The shoulder type is common in mold/die sets, where it also acts as a locating and thrust element for guide pillars.

The bearing runs without added oil or grease because graphite plugs supply the lubricating film, so it is described as oilless or self-lubricating. In practice, service life depends on load, speed, temperature, shaft condition, and environment; periodic inspection of wear and shaft finish is recommended. It removes the recurring lubrication task associated with oiled bearings rather than eliminating all inspection.

graphite bronze guide pillar bush

How to specify quickly

  1. Geometry: shoulder (flanged) or straight — note if combined radial + axial load exists.
  2. Dimensions: bore, OD, length, shoulder thickness & diameter.
  3. Alloy: state the base alloy, not the JDB code, to avoid cross-supplier mismatch.
  4. Duty: load, speed, temperature, and environment (dust / water / chemical).
  5. Shaft: hardness ≥ HRC 50 and ground finish Ra 0.4–0.8 µm.

Provide as much as available; we will confirm the specification against your application and the applicable standard.