Hamilton heavy duty dual wheel pneumatic casters — with paired air-filled tires for outdoor, rough-terrain, and high shock-load applications. 8″, 10″, 12″, 16″, 18″, 21″, and 25″ tire diameters. Capacities up to 7,600 lb per caster (15,200 lb per pair). Hamilton S-series swivel and R-series rigid configurations. Specified for aircraft ground support equipment, military trailers, construction carts, outdoor power tool transports, and any application crossing gravel, expansion joints, or uneven pavement.
Match wheel diameter to load capacity and terrain. All sizes available in swivel (S-) or rigid (R-) variants.
| Model Series | Wheel Size | Capacity | Bearing | Best For |
|---|---|---|---|---|
| S-7208 / R-7208 | 8″ | 1,800 lb | 3/4″ Straight Roller | Indoor-outdoor utility carts, light shop trucks |
| S-7210 / R-7210 | 10″ | 2,400 lb | 3/4″ Straight Roller | Outdoor utility, garden equipment, light trailers |
| S-7212 / R-7212 | 12″ | 3,200 lb | 1″ Straight Roller | Construction site carts, lawn equipment |
| S-72166 / R-72166 | 16″ | 4,400 lb | 1″ Tapered Roller | Aircraft ground support, light military |
| S-72188 / R-72188 | 18″ | 5,200 lb | 1-1/4″ Tapered Roller | Heavy ground support, mobile generators |
| S-72210 / R-72210 | 21″ | 6,400 lb | 1-1/4″ Tapered Roller | Aircraft tugs, large outdoor equipment |
| S-72250 / R-72250 | 25″ | 7,600 lb | 1-1/4″ Tapered Roller | Heaviest outdoor industrial, military trailers |
Smooth pavement: 8-10″ works fine. Gravel, expansion joints, light debris: 12-16″ minimum. Rough construction sites, uneven ground, deep gravel: 18-25″ required. Larger pneumatic tires absorb more shock and roll over obstacles with dramatically lower push-force. Trade-off — larger wheels raise deck height and increase swing radius.
Total load divided by 4 casters, then add 50% for shock loads on rough terrain (vs 30% for indoor). Dual wheel pneumatic capacities run 1,800 lb (8″) to 7,600 lb (25″) per caster. For 4-caster carts moving heavy outdoor loads, the 16″ S-72166 at 4,400 lb each is the most-specified size.
Hamilton S-series (swivel) and R-series (rigid) use identical wheel hubs and mounting plates. Standard configuration: 2 swivel front + 2 rigid rear for straight-line tracking on long outdoor pushes. All-swivel for tight maneuvering around aircraft, equipment, or storage yards. Identical part numbers minus the S/R prefix.
Straight roller bearings (8-12″ sizes): handle radial load only, lower cost, fine for utility applications. Precision tapered roller bearings (16-25″ sizes): handle radial + thrust loads, required for heavy aircraft and military applications where the wheel sees side loads during turning under full weight.
A caster with two air-filled tires mounted side-by-side on a single hub. The dual-wheel design doubles the load capacity of a single-tire pneumatic caster of the same diameter, distributes load across two contact patches for better stability on uneven ground, and provides redundancy — if one tire goes flat, the other carries the load until repair.
The Hamilton S-72250-PR / R-72250-PR series has a 7,600 lb capacity per caster at proper tire pressure. Four casters: 30,400 lb total cart capacity. This is the largest dual-wheel pneumatic caster Hamilton makes — specified for military trailers, aircraft tugs, and heaviest outdoor industrial equipment.
Yes — Hamilton Caster & Manufacturing manufactures all S-series and R-series dual-wheel pneumatic casters at their Hamilton, Ohio facility. ISO 9001 certified. Compliant for federal, defense, GSA, and Buy American Act procurement. Each caster includes a Hamilton certification tag.
S-series = swivel (S-72210-PR rotates 360°). R-series = rigid (R-72210-PR fixed direction, no rotation). Identical wheel, tire, bearing, and capacity. The difference is the top mounting plate and swivel raceway — rigid is lighter and lower cost. Standard pairing for a 4-caster cart: 2 swivel + 2 rigid for straight-line tracking.
Hamilton dual-wheel pneumatic casters ship standard with tubed pneumatic tires (rubber tube inside the casing). Tubed is the industry standard for industrial dual-wheel pneumatics — field-replaceable, available at any tire shop, lower cost. Tubeless conversions are not offered — the dual-wheel hub design requires tubed.
Straight (cylindrical) roller bearings: handle radial load (vertical weight) only. Used on 8-12″ dual-wheel sizes for utility applications. Precision tapered roller bearings: handle radial + thrust loads (side-load during cornering under weight). Used on 16-25″ sizes where aircraft tugs and trailers see lateral loads. Tapered bearings cost more but are required for heavy-duty outdoor use.
Yes, but it’s overkill for most indoor applications. Pneumatic tires excel where shock absorption matters — if your indoor floor is smooth concrete, solid polyurethane or rubber casters cost less, last longer, and won’t go flat. Dual-wheel pneumatic is the right choice when the cart crosses between indoor and outdoor surfaces (warehouse-to-yard, hangar-to-tarmac).
Yes — Hamilton stocks replacement pneumatic tires for every dual-wheel size (8″ through 25″). Email info@casterhq.com with the model number stamped on the caster body and we’ll ship a matched replacement tire kit. Average tire life under normal industrial use: 5-8 years. Tire pressure check every 30 days extends life significantly.
