Plate Caster Size & Capacity Tiers
Plate size correlates directly with capacity. Match plate to load and bolt-hole pattern on your existing equipment.
| Plate Size |
Tier |
Capacity Range |
Wheel Sizes |
Best For |
| 2-3/8″ x 3-5/8″ |
Light Duty |
75 - 350 lb |
2″ - 5″ |
Furniture dollies, tool boxes, light carts |
| 2-1/2″ x 3-5/8″ |
Light-Medium |
100 - 500 lb |
3″ - 5″ |
Service carts, food carts, light industrial |
| 3-1/8″ x 4-1/8″ |
Medium |
300 - 800 lb |
3″ - 6″ |
Shop carts, equipment dollies, medium loads |
| 4″ x 4-1/2″ |
Medium-Heavy |
500 - 1,500 lb |
4″ - 8″ |
Industrial carts, AGVs, manufacturing |
| 4-1/2″ x 6-1/4″ |
Heavy Duty |
1,000 - 3,000 lb |
6″ - 10″ |
Heavy industrial, towing, dock carts |
| 5-1/4″ x 7-1/4″ |
Heavy Duty |
2,000 - 5,000 lb |
8″ - 12″ |
Heavy machinery, foundry, steel mills |
| 6-1/4″ x 7-1/2″ |
Super Heavy |
5,000 - 12,000 lb |
10″ - 14″ |
Aircraft tugs, military, super-heavy industrial |
| 8-1/2″ x 8-1/2″ + |
Mil-Spec |
12,000 - 40,000 lb |
12″ - 24″ |
Mil-spec, aerospace ground support, custom |
How to Choose
1. Match Plate to Existing Bolt Pattern
If replacing casters on existing equipment, measure the bolt-hole spacing on the current mount — corner-to-corner across the diagonals. The plate size must match. The most common standard plates are 2-3/8″ x 3-5/8″ (light), 4″ x 4-1/2″ (medium-heavy, most popular), and 4-1/2″ x 6-1/4″ (heavy). Photograph the mount and email info@casterhq.com if you’re unsure.
2. Capacity Sizing
Total cart load divided by 4 casters, then add 30% for shock peaks on smooth indoor floors or 50% for outdoor and rough surfaces. Plate size correlates roughly with capacity — bigger plates spread load across more deck area and accept larger wheels. Don’t under-spec: a 1,000 lb load on 4 casters needs 325 lb per caster minimum.
3. Wheel Size by Floor Condition
Smooth concrete: 4-6″ works fine. Floor seams, light debris: 6-8″ minimum. Cracked concrete, outdoor, thresholds: 8-12″ required. Larger plate sizes accept larger wheels — if you need 10″ wheels for capacity, you need at least a 5-1/4″ x 7-1/4″ plate.
4. Swivel vs Rigid Configuration
Standard 4-caster cart: 2 swivel front + 2 rigid rear for stable straight-line tracking. All-swivel: tight maneuvering, AGVs, dock work. All-rigid: tow lines, fixed-path carts. Kingpinless swivel: shock-load applications where kingpin failure is the failure mode — specified for impact and high-cycle use.
Engineer Tip: The most common reason for caster failure is plate-size mismatch, not capacity. Even if the new plate has the right bolt-hole spacing, the plate dimensions must match the mount on the equipment — an over-sized plate can hit framework or wheels of adjacent casters during swivel. Always measure the available mounting envelope before ordering. CasterHQ engineers can pre-verify fitment — email info@casterhq.com with photos and equipment make/model.
Frequently Asked Questions
What is a plate caster?
A caster that mounts to equipment via a flat top plate with 4 bolt holes. The top plate transfers load and rotation forces between the equipment and the caster. Plate casters are the most common mount style in industrial caster applications — alternatives include stem casters (threaded or grip-ring), expanding adapter casters, and weld-on casters.
What is the most common plate size?
4″ x 4-1/2″ is the most-specified industrial plate size in North America — 1,788 of the 3,344 plate caster SKUs at CasterHQ use this plate. Capacity range: 500-1,500 lb per caster. Wheel size range: 4-8″. If your equipment uses an unmarked plate, 4″ x 4-1/2″ is the most likely fit.
How do I measure plate size for a replacement caster?
Measure the four bolt holes on your existing equipment mount — corner to corner across both diagonals. The two diagonal measurements give you the bolt-hole spacing. Also measure the overall plate dimensions of the existing caster (length x width). Both bolt pattern and plate dimensions must match for bolt-for-bolt replacement. Email info@casterhq.com with measurements for a cross-reference.
What is a kingpinless caster?
A kingpinless caster has no central kingpin in the swivel raceway. Instead, the swivel raceway is integrated into the top plate. Kingpinless eliminates the most common caster failure mode — kingpin loosening or shearing under shock loads. Required for high-cycle, impact, and shock-load applications. Capacity is typically 1,000-12,000 lb per caster.
What is the heaviest plate caster?
CasterHQ stocks Hamilton mil-spec plate casters up to 40,000 lb per caster (160,000 lb per 4-caster cart). These use 12″ x 15-3/8″ super-heavy plates with 16-24″ wheels. Specified for aerospace ground support, military equipment, foundry and steel-mill applications. Lead time on the largest sizes: 4-6 weeks. Contact info@casterhq.com for engineering and stock check.
What is the difference between steel and stainless plate casters?
Steel plate casters: zinc-plated or zinc-yellow chromate finish for indoor industrial use, lower cost, full capacity range. Stainless plate casters: 304 or 316 stainless construction for wet, washdown, food, pharma, and corrosive environments. Stainless costs 2-3x more and capacity is typically 70-80% of equivalent steel. Specify by environment.
Can plate casters be welded instead of bolted?
Yes — welded plate casters use the top plate as a weld attachment surface instead of bolt-through mounting. Common in custom carts where bolt access is limited. Weld-on requires steel plate (not stainless or aluminum). Specify weld-prep finish (no zinc plating — zinc fumes during welding) at order. Most steel plate casters in this catalog can be specified as weld-prep.
Do plate casters include mounting hardware?
No — plate casters ship without bolts because bolt length depends on the thickness of the equipment frame. Standard bolt sizes for industrial plate casters: 1/4″-20 for light duty, 5/16″-18 and 3/8″-16 for medium-heavy, 1/2″-13 for heavy duty. Use grade 5 zinc-plated steel bolts with washers and lock nuts. Match bolt count to plate (typically 4 per caster).
20 Plate Sizes In StockFrom 2-3/8″ x 3-5/8″ light-duty through 12″ x 15-3/8″ mil-spec. Every common industrial plate size stocked.
All Major BrandsHamilton, Albion, Faultless, Colson, Caster Concepts, Service Caster — full plate caster catalog from every Tier 1 manufacturer.
Same-Day Ship from TexasStock plate casters ship same day from Mansfield, TX before 3pm CT. Freight quoted at order for super-heavy sizes.
Engineer Cross-Reference844-439-4335 or info@casterhq.com for plate fitment, bolt-pattern match, and replacement specification. Real engineering, no scripts.
