Precision Double-Cut Edge Center Flanged Bronze Bushings Manufacturer
Designed specifically for heavy-duty, high-speed, and challenging maintenance industrial settings, our Double-cut Edge Center Flanged Bronze Bushings integrate advanced edge processing technology with a unique center-flanged structure. These bushings deliver exceptional wear resistance, significantly lower friction coefficients, and extended maintenance-free operational periods, making them an ideal alternative to traditional lubricated bearings. The core visual of this innovative solution features a golden bronze body, often punctuated with black graphite plugs, and a distinct central flange, highlighting its precision engineering.
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Core Performance and Features: Why Choose Our Double-cut Edge Center Flanged Bronze Bushing?
A double-cut edge centre flanged bushing is a machined bronze sleeve whose bearing length is split into two lands by a shoulder standing at the middle of the overall length, with both sleeve ends finished by a machined relief cut rather than left square. Because there is sleeve material on both sides of the shoulder, one part can take axial force from either direction, and the two separated lands support a shaft over a longer span than a single short bush would. The trade-off is that the centre shoulder has nowhere to go during assembly unless the housing is split or relieved, so this form asks more of the housing than an end-flanged bush does.
Our specialized bronze bushings are engineered to overcome common challenges in demanding applications, offering superior performance through their unique design elements.
Double-cut Edge Technology: Mitigating Stress and Enhancing Durability
raditional bushings often suffer from stress concentration at their edges, leading to premature wear and fatigue. Our Double-cut Edge Technology addresses this by applying a special cutting treatment to the bearing edges, creating both flow channels and pressure relief zones. This innovative design offers several critical advantages:
What the part looks like
Two features define the form, and both should appear on the drawing before anything is quoted:
- Centre flange. The shoulder sits at or near the mid-point of the overall length, leaving two bearing lands, one on each side. The flange face is buried inside the length rather than standing proud at an end.
- Double-cut edges. Both sleeve ends are machined back with a relief cut — either a chamfer combined with a short step, or a trimmed-back edge — giving each land a defined entry and a clean seat against a housing shoulder, instead of a raw square edge.
Naming for this family is not fully standardised across suppliers. Some use the term for a sleeve whose two ends are trimmed to a half-thickness step; others use it for any bushing with the shoulder away from the ends. Descriptions in words alone are not enough to price and machine a part reliably, so we work from a drawing or a sample, and we confirm flange position, cut depth and land lengths before scheduling.
The practical consequences of that geometry:
- The effective bearing span equals the distance between the outer edges of the two lands, which resists rocking and moment loads better than a short single bush of the same length-to-bore ratio.
- Axial force in either direction is taken by the same shoulder, so the part replaces a sleeve plus two washers in applications where the shaft moves both ways.
- The two bores must be concentric with each other, not merely to size. This is machined by boring both lands in one setting, or by finishing them together after installation.
- The bush cannot be pushed through a plain one-piece housing bore from one end, because the shoulder is wider than the bore.
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Centre flange compared with end flange
| Point | Centre flange | End flange |
|---|---|---|
| Bearing surfaces | Two lands, one either side of the shoulder | One continuous bore |
| Axial load direction | Both directions, from the same face | One direction only, unless doubled or paired with a washer |
| Overall length used | Whole length contributes to support span | Length beyond the housing is mostly locating |
| Housing requirement | Split housing, two-piece boss, or a central relief groove | Single flat face, optionally one counterbore |
| Assembly | Laid into one half of the housing, then closed up | Pressed axially into position |
| Machining cost | Higher — extra operations and concentricity control | Lower |
| Typical application | Intermediate supports, linkages, trunnions, reversing loads | General purpose locating and light thrust |
Where the application only needs axial location with light thrust, the end-flange form covered on the round flange bronze bushing page is normally the simpler and cheaper part. Where the bushing itself also has to be bolted down so it cannot rotate, the bolted version of that family is described under bolted thrust-type oilless bearings.
Graphite-Plugged Option: Maintenance-Free flanged Bushings
Our Graphite-Plugged Double-Cut Edge Center Flanged Bronze Bushings provide a truly self-lubricating solution for applications where regular maintenance is difficult or impossible. Solid graphite plugs embedded in the bronze create continuous lubrication during operation.
How It Works: Frictional heat forms a microscopic graphite film on the shaft, ensuring constant lubrication without oil or grease.
Key Benefits:
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Maintenance-Free Operation: No external lubrication needed, reducing failures, downtime, and costs.
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Extreme Environment Performance: Reliable across -200°C to +350°C (up to +400°C with special alloys), resistant to water, dust, and chemicals.
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Extended Service Life: Continuous graphite lubrication minimizes wear, enhancing bushing and component longevity.
Dimensions, proportions and tolerances
The table below gives ranges that are normally machined. Land lengths are usually kept roughly equal so that each side carries a comparable share of the load; large differences between the two land lengths are worth questioning, because the short land then runs at a higher pressure than the long one.
| Overall OD band | Typical bore range | Wall thickness | Land length, each side | Flange OD | Flange thickness | Typical OD interference |
|---|---|---|---|---|---|---|
| 20–60 mm (0.79–2.36 in) | 15–50 mm | 2.5–5.0 mm (0.10–0.20 in) | 10–40 mm (0.39–1.57 in) | 1.25–1.45 × OD | 3–7 mm (0.12–0.28 in) | 0.03–0.07 mm (0.0012–0.0028 in) |
| 60–120 mm (2.36–4.72 in) | 50–105 mm | 4.0–8.0 mm (0.16–0.31 in) | 20–80 mm (0.79–3.15 in) | 1.20–1.35 × OD | 5–12 mm (0.20–0.47 in) | 0.06–0.12 mm (0.0024–0.0047 in) |
| 120–250 mm (4.72–9.84 in) | 105–220 mm | 6.0–14.0 mm (0.24–0.55 in) | 30–150 mm (1.18–5.91 in) | 1.15–1.30 × OD | 10–20 mm (0.39–0.79 in) | 0.10–0.18 mm (0.004–0.007 in) |
| Above 250 mm (9.84 in+) | 220 mm and above | 10–25 mm and heavier | Per drawing | 1.12–1.25 × OD | 15–30 mm (0.59–1.18 in) | 0.15–0.30 mm (0.006–0.012 in) |
Tolerances that commonly cause disagreement between drawing and part:
- Concentricity between the two lands. Typical achievable figures are around 0.02–0.05 mm (0.0008–0.0020 in) for small and medium sizes, wider on large parts. Tighter than that usually means finishing both lands after installation.
- Flange position. Where the shoulder has to register in a groove, its position from one end is normally held to ±0.1–0.2 mm (±0.004–0.008 in) unless stated otherwise.
- Flange side face runout to the bore axis. Commonly in the order of 0.02–0.05 mm (0.0008–0.0020 in) total indicator reading for precision work.
- Cut depth at the edges. The relief cut is usually taken to roughly half the wall thickness or less; a deep cut leaves less material to carry load at the ends, where pressure peaks often occur.
- Bore closure after pressing. The bore typically shrinks by about 0.6 to 1.0 of the OD interference, depending on wall ratio; plan the pre-press size or a post-install finish accordingly.
Running clearance is normally taken as 0.1–0.2% of shaft diameter plus an allowance for thermal growth. Bore measurements should be read at 20 °C (68 °F) on the same equipment used for final inspection; see reading and measuring bearing tolerance.
Materials and the graphite-plugged option
| Alloy family | Typical hardness | Tensile strength, typical | Where it is used |
|---|---|---|---|
| C93200 leaded tin bronze (SAE 660) | 60–80 HB | 240–310 MPa | Moderate loads, dirty environments, softer shafts, occasional greasing |
| C90500 tin bronze (SAE 62, CuSn10Zn2) | 80–100 HB | 300–380 MPa | Heavier loads, reversing loads and shock in linkages and presses |
| C95400 aluminum bronze | 170–220 HB | 585–690 MPa | High load, slow oscillation, corrosive or wash-down service |
| C86300 manganese bronze | 180–240 HB | 750–830 MPa | Very high load at low speed; usually ordered graphite-plugged |
| Gunmetal and leaded gunmetal | 70–95 HB | 250–320 MPa | Water-lubricated and general marine duty where embeddability helps |
| Graphite-plugged versions of these bases | Follows the base alloy | Follows the base alloy | Dry running, inaccessible positions, high temperature |
The alloy choice follows the same reasoning as for any bronze bushing, and the centre-shoulder form does not change it. For high-load, slow, corrosion-exposed duty, there is background in the note on C954 aluminum bronze bushings and in the general overview of common bearing materials.
When no oil or grease can reach the bearing, rows of solid lubricant plugs are embedded in both lands. Points to settle:
- Coverage is commonly around 20–30% of each land area for rotation, more for slow oscillation or sliding.
- The thrust faces of the centre flange often run dry and should be plugged as well; say so explicitly on the drawing.
- Plugged bronze typically runs from about −40 °C (−40 °F) to roughly 250 °C (480 °F), with some bases usable near 300 °C (570 °F).
- Limiting PV for plugged bronze is commonly quoted around 1.0–2.5 MPa·m/s; dry friction coefficient usually settles near 0.10–0.20 once the transfer film forms.
- Plug pattern and sizing are set out in calculating plug size for graphite-plugged bronze bearings, and typical construction in graphite-plugged bronze bushings.
Installation notes
Assembly is where this form most often goes wrong, because the shoulder is wider than the bore it has to pass through:
- Housing. Either a split boss that closes around the flange, a two-piece pedestal, or a through bore with a machined relief groove for the shoulder. A plain one-piece bore cannot accept the part.
- Seating. The flange should sit in its groove with clearance on both faces, typically 0.1–0.3 mm (0.004–0.012 in) total for small and medium sizes, so that clamping the housing does not pinch the flange and distort the bore.
- Edge relief. The cut edges need their own clearance in the housing; if the housing shoulders bear on the cut steps rather than on the sleeve OD, the part is loaded eccentrically.
- Pressing. Use a mandrel that bears on the sleeve OD or the flange face, not across the bore. Never drive the part through the flange alone.
- Finish. Where both lands must be concentric within a few hundredths of a millimetre, machine them in one clamping or finish them together after the housing is closed.
- Shaft. For dry running, shafts softer than roughly 250–300 HB are usually roughened rather than polished by plugged bronze; a finish of Ra 0.4–0.8 µm (16–32 µin) is normally requested.
When a different design should be used
- Axial force is small. A plain sleeve is cheaper and the housing needs only a through bore. Adding a centre shoulder buys capacity that will never be used.
- Thrust acts in one direction only. An end flange costs less to machine and installs into a single-face housing.
- The housing cannot be split or grooved. Without axial relief there is no assembly route. Either redesign the housing or use an end flange with a retaining feature.
- Very heavy radial load with shock. A one-piece cast bushing with a generous wall distributes load better than a two-land part whose supports are interrupted by the flange; retaining arrangements referenced in machined bronze bushings made to drawing apply here.
- High surface speed. Sliding bronze is limited by PV regardless of form; above that limit, rolling bearings are the answer.
- Radial space is tight. A centre shoulder needs material thickness to exist; wrapped thin-wall bushings serve better, an example being wrapped bronze bushings in crane applications.
- Replace-in-place maintenance is required. Split and half bushings can be changed without withdrawing the shaft; a centre-shouldered sleeve generally cannot.
Where this form is used
Typical service is a support that sees reversing axial load, or a long boss where two separated lands improve alignment:
| Equipment | What the bushing does | Requirement that drives the design |
|---|---|---|
| Construction machinery booms, arms and bucket linkages | Supports the pin over a wide boss and locates it axially | Reversing load plus moment on each cycle |
| Cone crushers and other mineral processing equipment | Takes eccentric loads and keeps the part positioned axially | Heavy load at low speed, often graphite-plugged |
| Port and deck machinery — sheaves, linkages, pintles | Carries radial load with thrust from either direction | Corrosive environment, hard to reach for greasing |
| Valve and gate operating gear | Two lands keep the spindle guided over its travel | Long support span with axial thrust from the drive |
| Rolling stock bogies and transfer cars | Supports a through shaft at an intermediate point | Limited relubrication access |
Examples of heavy equipment duty are collected in bushings for excavators and earthmoving equipment and cone crusher bushings. Parts of this shape are generally finished on turning centres with the bores produced in one setup; see CNC machining of bronze.
Selecting dimensions: short checklist
- Bore, outside diameter, total length, land length each side, flange OD and thickness, edge-cut depth.
- Flange position, and how much axial clearance it needs in the housing.
- Radial load, axial load, direction changes, speed or oscillation angle, duty cycle.
- Temperature range, medium, presence of abrasive solids, availability of lubrication.
- Alloy preference, or alternatively the operating conditions so one can be proposed.
- Tolerance requirements: bore tolerance before or after installation, concentricity between the lands, squareness of the flange faces.
- Quantity for the first order and for repeats, plus the delivery destination.
What to send for a quotation. Drawing or dimensions — bore, outside diameter, total length, flange OD and thickness, land lengths and flange position; material if specified, otherwise the operating conditions including load, speed or oscillation angle and temperature; tolerance requirements, especially concentricity of the two lands; quantity for first and repeat orders; and the delivery destination so freight and packing are quoted correctly.
Send those details to una@viiplus.com and we will confirm the form, propose a material with numbers, and quote against the drawing.
