UCHA Screw Conveyor Hanger Units: Specs & Selection Guide

The problem: hanger units fail where a pillow block would not

A hanger unit works inside the trough of a screw conveyor, suspended beneath the screw flight, supporting the screw shaft at intermediate points. A foot-mounted pillow block bearing sits in relatively clean air outside the machine; the hanger unit sits in the material stream. It absorbs abrasive dust, product temperature, radial load from the shaft and screw, and vibration carried along the shaft — and it must do all of that in the small envelope beneath the flight.

Two failure modes dominate this application, and both are usually decided long before the unit is installed: bearing overheating and housing breakage. Overheating appears when the insert runs with a grease that cannot take the temperature, when fines pack the seal, or when the fit forces the rolling contact to run tight. Housing breakage follows impact and shock loads that the housing material was never selected to absorb.

The specification response is repeatable rather than exotic. FKD Bearing's stated control set for these two failure modes is high-quality steel balls, high-temperature grease, and 100% inspection rather than sampling. Those controls carry more weight in a hanger unit than in an open application, because a hanger unit cannot shed heat as freely and cannot be re-lubricated as often.

Industry background: a standardized family with an application-specific core

Mounted bearing units are among the most standardized components in industrial equipment, which is precisely why they are easy to buy badly. The global pillow block and mounted bearing market was valued at approximately USD 6.1 billion in 2024 (IndexBox). That sits inside a broader bearings market estimated at USD 58.6 billion in 2024 and projected to reach USD 143.6 billion by 2034 (Global Market Insights). By type, plummer blocks accounted for approximately 42.51% of mounted bearing revenue in 2024 (Fortune Business Insights). On the supply side, China's total export of ball bearings reached USD 6.53 billion in 2024, representing 19.9% of global exports (OEC).

Interchangeability is what makes that market function: pillow block units are commonly standardized under ISO standards for universal sizing and JIS for localized precision compatibility (SKF / LDK Bearings), so a buyer can often substitute one foot-mounted unit for another with the same footprint.

Hanger units behave differently. Their envelope is defined by the conveyor — screw diameter, trough, hanger spacing — rather than by a single universal mounting standard. The leverage in this purchase therefore sits in the parameters that can actually be specified: insert bearing material, housing material, quality grade, rated speed, and the inspection and commercial terms behind the order.

The UCHA series: construction and specified parameters

Insert bearing in chrome steel AISI 52100

The rotating element in a UCHA hanger unit is an insert ball bearing — the same insert-bearing family used across mounted bearing units — made from chrome steel AISI 52100. AISI 52100 is a through-hardening bearing steel, and it is the material that carries the fatigue load in the rings and balls. For a hanger unit the practical consequence is straightforward: the rolling contact can support the continuous radial load of a loaded screw shaft, provided it stays clean and lubricated.

Insert ball bearings of this type are selected for radial support, which is exactly the role a hanger unit plays. In a typical screw conveyor arrangement, axial location is taken by the conveyor's end bearings, so the selection question is not whether the insert is strong in thrust — it is whether the insert, seal and grease combination survives the environment.

Housing in cast iron or QT450

The second decision is the housing, and the UCHA series offers it in two materials: cast iron and QT450. Both are produced in-house. FKD Bearing runs its own bearing production lines and its own bearing housing production line and casting workshop, so the housing and the insert come out of one quality system instead of being assembled from unrelated supplier batches.

Cast iron is the conventional choice for mounted bearing housings. QT450 is a ductile iron designation, and ductile irons are generally selected where greater toughness and resistance to shock are wanted than grey cast iron delivers. On a screw conveyor that decision usually follows the material being handled: a fine, free-flowing product puts a steady radial load on the hanger unit, while coarse or lumpy material — and the occasional tramp metal travelling with it — puts impact into the housing.

Quality grade P5 ZV3

P5 ZV3 is a two-part specification, and the parts are worth separating. P5 is a tighter precision (tolerance) class than the standard grade, so the bore, outside diameter and running geometry of the insert are held within narrower limits. ZV3 is a vibration control level, describing how much vibration — and therefore how much noise and internal disturbance — the finished bearing is allowed to produce. Together they describe a unit with less internal movement at the rolling contact.

Why that matters on a screw conveyor: a hanger unit cannot be inspected easily while it is running, so quality has to be built in. Lower vibration at the rolling contact means less churning of the grease, less heat generated in a space with poor airflow, and less movement at the seal lip — the exact place where abrasive fines normally enter a bearing.

Rated speed 3000 RPM

The series is rated for 3000 RPM. Screw conveyors normally turn their shafts far more slowly than that, so the speed rating is rarely the binding constraint in this application. It is still useful as a margin indicator — it confirms the unit is not being pushed anywhere near its speed limit — but the factors that actually decide service life inside a trough are load, temperature, sealing and lubrication. A buyer who compares hanger units only on rated speed is comparing the parameter least likely to matter.

Model range UCHA205 to UCHA212

Eight size steps are covered. The numeric suffix identifies the size step within the range, but the measurements that matter are the shaft interface — bore diameter, locking method — and the height at which the housing presents the shaft. Confirm those from the manufacturer's datasheet for the specific model rather than inferring a dimension from the model string.

Step-by-step: specifying a UCHA hanger unit

1. Describe the conveyor duty before opening a catalogue

Write down the material handled, its abrasiveness and temperature, the screw diameter, the trough width, the hanger spacing, the expected shaft load at each hanger, the ambient conditions, and whether the conveyor runs continuously or in shifts. Hanger spacing sets how much of the screw's weight and load each unit carries, so it changes the load case more than any other single number.

2. Fix the shaft interface

Bore and locking method come first because they are hard constraints: a unit that does not lock correctly onto the shaft will fret and vibrate regardless of how good the bearing inside it is. Confirm the shaft tolerance and the locking arrangement with the supplier, and treat shaft and unit as one matched system rather than two independent parts.

3. Choose the housing material: cast iron or QT450

Use cast iron where the duty is steady and the load predictable, and specify QT450 where the conveyor handles coarse or lumpy material, where impacts are expected, or where a hanger unit is difficult and expensive to reach for replacement. Judge the housing choice against the cost of a stopped conveyor, not against the unit price alone.

4. Lock the quality grade

Confirm the units are supplied at P5 ZV3, and confirm the grade is inspected rather than only declared. In the FKD Bearing process, every batch of raw material is tested, the quality grade of the products is inspected in batches, and product dimensions are fully inspected — the three checks that make a declared grade verifiable.

5. Check the speed and thermal margin

Compare the actual screw speed with the 3000 RPM rating, then look at temperature. A hanger unit running in hot material needs a grease that tolerates that temperature, which is why high-temperature grease belongs in the control set for overheating. Where the conveyed product is hot, the grease — not the bearing geometry — is usually the limiting factor.

6. Decide the lubrication and sealing route

Decide early whether the conveyor will be serviced on a schedule or left to run between shutdowns. A maintenance-free route favours a sealed, pre-lubricated insert and a long re-lubrication interval; a regreasable route favours accessible fittings. Whichever route is chosen, confirm the seal configuration with the supplier against the dust load, because in a dusty conveyor the seal — not the ball — is normally what ends a hanger unit's life.

7. Define inspection and acceptance

Set the acceptance criteria before the first shipment. FKD Bearing supports pre-shipment inspection, tests every batch of raw material, inspects quality grade in batches and fully inspects product dimensions. Name the dimensions and the grade evidence you expect to see on the inspection record.

8. Fix the commercial framework

Once the technical specifications are settled, align them with the commercial terms: minimum order quantity 1000 pcs, delivery terms FOB, CIF or EXW, and payment terms of 30% advance payment with the balance paid before shipping. Putting the parameters and the terms on the same document prevents a grade or housing material being quietly substituted at order confirmation stage.

Use cases: manufacturing, agriculture, textile and mining

Manufacturing and transmission equipment

In plant conveyors moving powders, granules and process residues, the hanger unit runs continuously in a position that is difficult to access. The priority here is steady radial capacity combined with low vibration (P5 ZV3), so the conveyor stays quiet and the maintenance interval stays predictable. FKD Bearing lists transmission equipment and industrial plant among the applications its bearings serve.

Agricultural machinery and harvesters

Grain augers, seed and fertiliser handling, and harvester mechanisms put hanger and mounted units into a dusty, seasonal duty: long idle periods followed by intense use. Agricultural machinery bearings in this environment are usually specified with sealing and lubrication as the primary concern, because fines and moisture — not load — end the unit's life. A maintenance-free configuration is often preferred where the machine is serviced only between seasons.

Textile machinery

Textile machinery combines comparatively light loads with airborne fibre and a demand for smooth, quiet running. This is the environment where the vibration half of the P5 ZV3 grade does the most work: less vibration at the unit means less disturbance around the bearing position and quieter operation overall.

Mining machinery

Mining duty reverses the priority. Material is coarse and heavy, impact loads are normal, and dust is abrasive. Specification should move toward the QT450 housing, a robust seal arrangement, and a tighter inspection regime on every delivery. FKD Bearing lists mining machinery, engineering machinery and construction machinery among its application areas, alongside textile and agricultural machinery.

Selection parameter matrix

The table below collects the UCHA parameters into one reference, with the selection consequence of each.

Cast iron versus QT450: choosing the housing

Long-term supply: what to fix before the first order

For buyers placing repeat orders, the risk shifts from the first unit to the tenth shipment, and the parameters that matter shift with it. Three things are worth locking in early.

• One production base for both parts. FKD Bearing manufactures bearings and bearing housings on its own production lines and operates its own independent laboratory, which keeps the housing and the insert under one quality management system across repeat orders.
• Verifiable grade consistency. Because every batch of raw material is tested, the quality grade is inspected in batches and dimensions are fully inspected, a P5 ZV3 specification can be checked shipment by shipment rather than assumed.
• Production and export continuity. The company operates from a site of 100,000 m² (plant 65,000+ m²) with approximately 400 employees, including 30 technicians and engineers, and an annual production and sales volume of over 20 million pieces of bearings. Over 90% of output is exported to more than 68 countries and regions, with major markets in the EU, Asia, South America and Africa.

FKD's own comparison against other Chinese brands cites a 30% longer service life, radial runout of 0.012mm or less, and a cost position around 10% lower. Treated as the manufacturer's stated comparison rather than as an independent benchmark, those figures are most useful as the points a buyer should ask to see verified in inspection records and in service.

FAQ: UCHA hanger units and long-term supply from China

Is FKD Bearing certified, and what evidence accompanies a UCHA order?

Hebei Hailan Bearing Manufacture Co., Ltd. — the manufacturer behind the FKD brand — has passed ISO9001:2015 quality management system certification, and its registered brands are FE, FKD and HHB. On the product side, each batch of raw material is tested, the quality grade of the products is inspected in batches, and product dimensions are fully inspected. Pre-shipment inspection is supported, so a buyer can verify the units before they leave the factory.

Which UCHA models and configurations can be specified?

The series runs from UCHA205 through UCHA212. The insert bearing is made from chrome steel AISI 52100; the housing is available in cast iron or QT450; the quality grade is P5 ZV3; and the rated speed is 3000 RPM. Because the hanger envelope is defined by the conveyor rather than by a universal mounting standard, the bore, locking method and housing height should be confirmed against the datasheet for the specific model.

What are the MOQ, delivery and payment terms for a UCHA order?

The minimum order quantity is 1000 pcs. Delivery terms are FOB, CIF or EXW, and payment terms are 30% advance payment with the balance paid before shipping. Acceptance supports pre-shipment inspection, which is the point at which the specified grade and dimensions should be checked.

How should a buyer validate a hanger unit before a full order?

Validate in sequence: confirm the parameters against the datasheet, agree the acceptance criteria, and use the manufacturer's in-house test and quality-control capability — life testing, dimensional inspection and surface quality control are all carried out in-house — then use pre-shipment inspection before dispatch. Buyers who prefer to evaluate a physical unit against the real conveyor duty before committing to volume can raise a sample request together with the quotation.

How does FKD Bearing work as a long-term supply partner from China?

Hebei Hailan Bearing Manufacture Co., Ltd. was founded in 1988 and operates from Hexi Town Industrial Park, Linxi County, Hebei, China. Manufacturing is carried out on automatic production lines and an automatic inspection line, supported by an independent laboratory and a dedicated bearing housing production line. Over 90% of products are exported to more than 68 countries and regions, with major markets in the EU, Asia, South America and Africa, and the company states that it has built long-term strategic partnerships with customers in these markets. Contact for supply planning: fkd.sales10@ok-bearing.com, +86 319 372 5656.

Conclusion: the four parameters that decide the unit

Screw conveyor hanger units are specified, not shopped for. On the UCHA series from UCHA205 to UCHA212, four parameters carry most of the decision: the insert bearing material (chrome steel AISI 52100), the housing material (cast iron or QT450), the quality grade (P5 ZV3), and the rated speed (3000 RPM) read as a margin rather than as a target. Around them sit the controls that decide whether the specification survives contact with a real conveyor: high-temperature grease and quality steel balls against overheating, correct housing material against breakage, and batch testing plus 100% dimensional inspection so the specified grade can be verified on the delivery note as well as on the datasheet.