Dual Spring PU Heavy Duty Caster 6 Inch 8 Inch Lockable Brake for Industrial Assembly Lines

(A04-1KU Series — Iron Core Polyurethane, Shore 95A, Galvanized Bracket)

The 6" (150 mm) model in the A04-1KU Series is a super heavy duty, impact-resistant flat iron core caster built for extreme loads. Each wheel carries up to 1,300 kg (2,866 lbs), giving a combined 5,200 kg (11,464 lbs) system load on a standard four-caster setup.

The 75 mm wide flat PU tread creates an exceptionally large contact patch for outstanding stability and floor protection under extreme point loads.

Crucially, this caster is a SHOCK-ABSORBING model — every impact-resistant A04 caster is fitted with dual spring suspension, so it actively absorbs shocks, vibrations and impact loads rather than transferring them directly into the wheel, bearing, bracket and the equipment above.

• ★ Dual Spring Suspension (Shock Absorption): two calibrated coil springs built into the bracket absorb shocks, vibrations and impact loads from rough floors, expansion joints and debris — protecting the load, the wheel, the bearing and the operator.
• ★ Impact-Resistant by Design: every impact-resistant A04 caster is spring-mounted, so it flexes under冲击 loads and returns to position, rather than cracking or delaminating under heavy shock.
• Iron Core Polyurethane (PU), Shore 95A: the PU tread is permanently cast/bonded to a solid steel iron core — it cannot delaminate under load. Shore 95A PU is tough, cut- and abrasion-resistant, with low rolling resistance and high rebound.
• 75 mm Extra-Wide Flat Tread: larger contact patch = dramatically lower floor pressure, better lateral stability and easier rolling under the same heavy load compared with a standard 50 mm wide wheel.
• Hot-Dip Galvanized 8 mm Steel Bracket: thick bonded zinc coating resists rust, humidity, cutting fluids and wash-down; 8 mm formed steel handles shock loads without bending or de-welding.
• 6205 Precision Sealed Ball Bearing: large bearing (25*52*15 mm) selected for heavy radial and impact loads; sealed against dust, grit and moisture.
• Reinforced 160*160 mm Top Plate (10 mm thick): spreads mounting stress evenly across the equipment base — no plate flex, no pull-out, no base damage.

All impact-resistant A04 casters — including this model — are equipped with dual spring suspension. Two calibrated coil springs are built into the bracket assembly and work together to absorb impact energy before it reaches the wheel, bearing, bracket and the equipment above.

• Absorbs shock & vibration: when the wheel hits floor seams, expansion joints, weld slag, debris or uneven surfaces, the springs compress and deflect, soaking up the impact instead of transmitting it upward.
• Protects sensitive & fragile loads: critical when moving transformers, switchgear, precision moulds, electronic assemblies or delicate components that cannot tolerate jarring.
• Extends service life: by cushioning the wheel, bearing and bracket, spring suspension reduces fatigue, wear and premature failure — especially in 24/7 foundry, steel-mill and heavy-transfer operations.
• Improves operator comfort & safety: less vibration transferred to the trolley and handler; more stable, controlled movement under heavy loads.
• Stable within rated load: the springs are calibrated to the caster's rated capacity, so the wheel remains firmly supported and returns to its neutral position after each deflection — no bottoming out under normal service loads.

The A04 Super Heavy Duty series is equipped with a Side-Pedal Treadlock Brake — a rugged, foot-operated locking system featuring a long black lever handle that engages the wheel tread (or axle) to bring your equipment to a complete, secure stop. Unlike a small side-push brake that is easy to bend or kick accidentally, this industrial-grade pedal is designed for operators wearing safety boots in demanding environments.

How It Works:

Step down on the long black lever → the brake pad/mechanism presses firmly against the wheel tread or locks the axle → the wheel is immobilized while the dual springs continue to absorb floor shock and vibration in the vertical plane. This means your load stays put, yet the caster still cushions the equipment from bumps and gaps.

This brake configuration is the right choice for customers who:

• Operate extra-heavy loads that MUST NOT roll unintentionally: safety is critical when moving 1,300–1,500 kg per caster.
• Work on uneven floors, expansion joints or rough concrete: the dual springs absorb impact but the brake must hold position during loading and unloading.
• Need hands-free, foot-operated control: common in welding shops, foundries, steel mills and shipyards where operators' hands are occupied or gloved.
• Run slow-moving or stationary-heavy workflows: e.g. mould changeover, transformer positioning, die setup — where the caster stays locked for extended periods.
• Require maximum uptime and low maintenance: the simple mechanical design has no fragile parts to fail.

The Side-Pedal Treadlock Brake on the A04 series is purpose-built for the following heavy-duty environments and equipment:

• Metal Fabrication & Heavy Machinery: steel plate cutting & welding tables, steel coil & sheet metal transfer cars, die carts & mould carriers, heavy welding positioners
• Foundry, Forging & Rolling Mill: ladle & crucible transfer cars, ingot & billet handling trolleys, rolling mill roll changing carts, heavy casting handling bogies
• Power Generation & Energy: transformer & switchgear dollies, generator & turbine component carts, wind-turbine nacelle & blade handling rigs
• Shipbuilding & Offshore: ship block & section transport bogies, heavy component assembly skates, propeller & shaft handling trolleys
• Construction & Infrastructure: precast concrete formwork trolleys, bridge girder handling systems, tunnel-boring & pipe-jacking equipment skates
• Warehousing & Logistics (Super-Heavy): coil & roll storage shuttles, heavy-duty AGV & transfer carts, container & pallet heavy-load dollies

Typical uses for the A04-1KU series (this size and larger):

• Heavy mould carriers & die carts (medium-to-large stamping dies)
• Steel coil, sheet-metal & plate transfer cars
• Welding positioners, fabrication tables & structural steel jigs
• Foundry ladle transfer cars & heavy casting bogies
• Transformer dollies & switchgear handling trolleys
• Wind-turbine component & generator-part transfer rigs
• Shipyard block-transport & heavy-component assembly skates
• Heavy-duty AGV & automated transfer carts

Because this caster is spring-mounted, it is especially suited to routes and environments where floor conditions and impact loads matter:

• Die-change trolleys moving over floor seams and expansion joints
• Foundry & forging transfer cars on rough concrete
• Transformer and switchgear dollies carrying sensitive assemblies
• Heavy AGV routes with welded seams and floor irregularities

• PU tread permanently bonded to a solid steel iron core — cannot delaminate under load (unlike glued rubber tyres).
• Shore 95A is a hard, high-rebound industrial compound: cut-, chunk- and abrasion-resistant against steel shavings, weld spatter, slag and rough concrete.
• PU is naturally self-lubricating, low-friction and highly resistant to oils, greases, alkalis and most industrial chemicals — a clear advantage over natural rubber in factory and foundry environments.
• The flat (zero-crown) 75 mm tread keeps the full width in contact with the floor for maximum stability and load distribution.

• Hot-dip galvanized finish forms a thick, bonded zinc coating that protects against rust, humidity, cutting fluids and wash-down — far superior to painted brackets.
• 8 mm thick formed steel plate handles shock loads without bending, cracking or de-welding — essential at this load rating.
• Precision robotic welding on every load-bearing joint.

• Large 6205 bearing (25*52*15 mm) selected specifically for heavy radial and impact loads.
• Sealed construction keeps dust, grit and moisture out while retaining lubrication — maintenance-free in normal service.
• Runs smooth and quiet even at full load.

Standard casters typically use a 50 mm wide wheel. Here is why the 75 mm extra-wide tread matters:

• Larger contact patch = much lower floor pressure: a 1,300 kg load spreads over 75 mm of tread instead of 50 mm, so the wheel will not sink into soft flooring, epoxy coatings or lightweight workshop surfaces.
• Superior weight distribution on uneven floors: the wider footprint bridges expansion joints, floor seams and small gaps without the wheel dropping in.
• Outstanding lateral stability: strongly resists tipping and racking when a heavily loaded trolley is pushed off-axis or turned sharply — essential for tall, narrow mould carriers and transformer dollies.
• Reduced rolling resistance: the broad tread deforms less under compression, so it rolls more freely and requires less push force than a 50 mm wheel carrying the same load.
• Longer service life: wear is distributed over a larger tread volume, reducing downtime and replacement cost.

Both iron-core and aluminium-core wheels use a metal centre to support the tread, but they serve different purposes. This A04 model uses an IRON (STEEL) CORE — here is how the two compare:

• Iron Core (this A04) — best for: super-heavy, shock- and impact-loaded duty: transformer & switchgear dollies, steel coil cars, die/mould carts, foundry & rolling-mill transfer cars, shipyard bogies, heavy AGV — rough concrete, weld spatter and extreme loads.
• Iron Core — limits: heavier (higher push effort); steel can rust if coating is compromised; the harder tread is less forgiving on very soft, polished or delicate floor surfaces.
• Aluminium Core (A05) — best for: medium-duty, lighter, corrosion-sensitive applications: food & beverage, wash-down, humid/coastal, indoor logistics, electronics and light industrial — where low weight and floor gentleness matter.
• Aluminium Core — limits: lower load capacity and lower impact/shock tolerance — not suitable for超重载, foundry, steel-mill or heavy-impact duty; the lighter core cannot match iron for extreme loads.

As a professional industrial caster manufacturer with 10+ years of factory experience, we welcome OEM/ODM orders and can customize any combination of wheel and bracket to your requirements — including different wheel materials and different bracket thicknesses:

• Wheel material: PP / PU / TPR / Rubber / Nylon / Phenolic / Forged steel / Cast iron
• Wheel hardness: Shore A 70–100 (or D scale for PP/Nylon)
• Wheel colour: Any RAL colour
• Core / centre: Iron core, aluminium core, no core
• Bracket: Galvanized / Stainless 304 / Stainless 316 / Painted
• Bracket thickness & top plate size: to your drawing
• Mounting type: Top plate / Threaded stem / Bolt hole / Expanding adapter / Central hole
• Brake type: No brake / Side lock / Total lock / Direction lock
• Bearing: Plain / Roller / 6203 / 6204 / 6205 / 6305 etc.
• Shock absorption: With or without dual-spring suspension, per your requirement
• Special features: Anti-static (ESD), high-temperature, food-grade, explosion-proof, dual-wheel, spring suspension

Send us your drawing, sample or requirement — we will engineer the right caster for your application.

Q: What is the load capacity of the 6" (150 mm) A04 caster?
A: Each caster is rated for 1,300 kg. A standard 4-wheel set therefore supports approximately 5,200 kg — always apply a safety margin and contact us for dynamic (moving) load calculations.

Q: Does this caster have spring suspension?
A: Yes. Every impact-resistant A04 caster is fitted with dual spring suspension as standard, so it actively absorbs shocks and vibrations rather than transferring them to the load and equipment.

Q: What type of brake does the A04 caster use?
A: It uses a Side-Pedal Treadlock Brake — a rugged, foot-operated long-lever brake that engages the wheel tread or locks the axle for a secure stop. The brake works in conjunction with the dual springs: the wheel locks firmly, yet the springs continue to absorb floor shock and vibration. Ideal for heavy loads that must not roll unintentionally.

Q: What is the difference between the 75 mm wide wheel and a standard 50 mm wheel?
A: The 75 mm tread creates a much larger contact area, lowering floor pressure, improving lateral stability, bridging floor gaps and reducing rolling resistance under the same load.

Q: What is the wheel material and hardness?
A: Iron Core Polyurethane (PU), Shore 95A — permanently bonded to the iron core, cut- and abrasion-resistant, with low rolling resistance and high rebound.

Q: Is the bracket galvanized?
A: Yes. The 8 mm thick steel bracket and fork are hot-dip galvanized for maximum corrosion resistance, outperforming painted alternatives.

Q: Can I get rigid, swivel and brake versions?
A: Yes — A04-R-1KU-6*3 (Rigid), A04-S-1KU-6*3 (Swivel) and A04-T-1KU-6*3 (Swivel + Total Brake) are all available.

Q: Do you offer customization?
A: Absolutely. With 10+ years of factory experience, we welcome OEM/ODM orders — see the Custom Orders section above.

We are a professional industrial caster manufacturer with 10+ years of factory experience. Contact us today for a quote, free sample or engineering consultation.