Selection by Application Type
Pre-configured spec recommendations for the most common industrial cart types.
| Application |
Load Per Caster |
Wheel Material |
Wheel Diameter |
Bearing |
Mount |
| Warehouse cart |
800-1,500 lb |
Polyurethane on iron |
5-6 inch |
Annular ball |
4x4-1/2 plate |
| Production line cart |
500-1,200 lb |
Polyurethane 90A |
4-5 inch |
Annular ball |
4x4-1/2 plate |
| Tow line cart |
1,500-3,000 lb |
Polyurethane on iron |
6-8 inch |
Tapered roller |
5x6-1/4 kingpinless |
| Dock cart |
1,500-2,500 lb |
Polyurethane on iron |
8 inch |
Tapered roller |
5x6-1/4 kingpinless |
| Bakery rack (oven) |
200-500 lb |
Cast iron, hi-temp |
5 inch |
Hi-temp grease pack |
4x4-1/2 plate |
| Food prep cart |
200-500 lb |
TPR, stainless |
5 inch |
Sealed precision |
4x4-1/2 plate |
| Hospital bed |
200-400 lb |
TPR, soft rubber |
5 inch |
Sealed precision |
Grip ring stem |
| Tooling cart (aerospace) |
2,500-8,000 lb |
Cast iron, forged steel |
8-10 inch |
Tapered roller |
6-1/2x7-1/2 kingpinless |
| AGV / AMR platform |
500-3,000 lb |
Polyurethane 95A |
6-8 inch |
Sealed precision |
Kingpinless required |
| Cleanroom cart |
100-500 lb |
Polyurethane 85A or Delrin |
4-5 inch |
Sealed precision |
4x4-1/2 stainless |
Decision Tree
Quick Decision Tree
For procurement teams who want a fast answer without working through 7 variables.
-
Floor finished and load under 500 lb per caster? TPR or soft rubber, 5 inch, ball bearing, standard plate. Done.
-
Smooth or sealed concrete and load 500-1,500 lb per caster? Polyurethane on iron 85A-90A, 5-6 inch, annular ball, 4x4-1/2 plate. Default industrial.
-
Cyclic dock plate impact or tow line above 1,500 lb? Kingpinless construction, polyurethane on iron, 6-8 inch, tapered roller, 5x6-1/4 plate or larger.
-
Washdown, food contact, NSF/USDA? Stainless components, TPR or food-grade poly, sealed precision bearing, 4-5 inch.
-
Above 200°F (oven, bakery rack)? Cast iron wheel, hi-temp grease, hi-temp seals if sealed. Phenolic acceptable to 250°F.
-
AGV, AMR, or powered platform? Kingpinless construction required. Sealed precision bearings, polyurethane 95A on iron.
-
Heavy-duty aerospace, foundry, forge? Forged steel rig, cast iron or forged steel wheel, tapered roller, 6-1/2 x 7-1/2 plate or 8x10 plate. Talk to an engineer.
Common Mistakes
Caster Selection Mistakes
-
Specifying by static load rating instead of dynamic. Dynamic is typically 60-80% of static. Carts move. Always spec to dynamic.
-
Skipping the safety factor. Real applications need 1.5x to 2x over calculated load. Uneven floors, dock plates, off-center loads all matter.
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Picking wheel material by cost instead of floor type. The wrong material destroys floors, costs more in damage than any caster savings.
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Sizing wheel diameter too small. Wheel diameter is the single biggest factor in push force and obstacle clearance. Go larger when in doubt.
-
Mixing brake types or wheel sizes across one cart. Creates drift, uneven wear, and dangerous handling on slopes.
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Not checking overall height under load. Compressed height matters for dock door clearance, conveyor handoff, and tilt-cart geometry.
Engineering Selection Guide · 2026
How to Select Industrial Casters — A 7-Variable Engineering Spec Process
Specifying the wrong industrial caster is the #1 cause of premature failure in material handling. This guide walks the seven variables OEM engineers and MRO buyers must spec in order — load, mounting, wheel material, diameter, swivel construction, bearings, and brake action — with the failure modes if you skip any.
Caster selection is sequential — each variable narrows the next. Skip a step and you end up over-spec'ing on capacity (paying premium for unused load rating) or under-spec'ing on construction (failing under cyclic load within 6 months). This guide is the same 7-step process CasterHQ engineers use when sizing OEM custom builds.
Step 1 — Calculate Required Load Per Caster
Use the N-1 method: total loaded weight divided by (caster count − 1), then multiplied by safety factor (1.25 indoor concrete, 1.35 dock plates, 1.5 towed, 1.75 outdoor). N-1 accounts for one caster lifting off uneven floors. For 8+ caster carts use N-2.
Required = (Weight ÷ (N−1)) × Safety Factor × Duty Factor
Use the Load Calculator for the math.
Step 2 — Pick Mount Type
Plate (4-bolt, strongest, most common), threaded stem (screws into tapped hole), grip ring stem (snaps into tubular leg), or expanding stem (clamps inside hollow tube). Plate is the safest spec for any new design. Full mounting guide.
Step 3 — Match Wheel Material to Floor
Floor surface eliminates incompatible compounds first. Tile/vinyl/wood: poly or rubber only. Outdoor: pneumatic or steel. Wash-down: stainless or sealed poly. High-temp (200°F+): phenolic or cast iron. Standard concrete: anything works — pick by load + ergonomics. Full materials guide.
Step 4 — Size Wheel Diameter
Three rules in order: (1) capacity floor — match diameter to load tier (4" up to 600 lbs, 6" up to 1,500 lbs, 8" up to 2,500 lbs), (2) 4× obstacle rule — diameter must be at least 4 times your largest floor obstacle, (3) operation mode — AGV needs 8" minimum, towed needs 6" minimum. Diameter selection guide.
Step 5 — Choose Swivel Construction
Above 1,500 lbs/caster OR for any cart with frequent direction changes: kingpinless construction is mandatory. Kingpin caps swivel load at the kingpin's shear strength — fails under cyclic load within 6-12 months. Kingpinless raceways handle 40% more cyclic load and last 3-5x longer. Kingpin vs kingpinless guide.
Step 6 — Spec Bearing Class
Roller bearings (standard) work for light/medium duty, cap at ~1,500 lbs. Tapered roller for heavy + axial loads. Sealed precision adds 15% capacity + cuts force 18%. Maintenance-free (lifetime sealed) cuts force 25% and eliminates re-greasing — mandatory for continuous-duty (8+ hour daily) applications. Bearing types guide.
Step 7 — Add Brake / Action Type
Wheel brake (face brake) stops wheel rotation only. Total lock stops both wheel and swivel — mandatory for parking on inclines or earthquake zones. Side lock allows wheel rotation but locks swivel direction (towed tracking). Default: 2 swivel front + 2 rigid rear for towed carts; 4 swivel + 2 diagonal brakes for manual omnidirectional.
7-Variable Spec Checklist
-
Load per caster — N-1 method × safety factor × duty factor
-
Mount type — plate, threaded stem, grip ring, or expanding stem
-
Wheel material — match floor first, then load + environment
-
Wheel diameter — capacity floor + 4× obstacle rule + operation mode
-
Swivel construction — kingpin under 1,500 lb / kingpinless above
-
Bearing class — roller / tapered / sealed precision / maintenance-free
-
Brake / action — swivel + rigid mix, brake placement, total lock if parked
Engineering Spec Help
Outside the standard 7-variable space?
Custom durometer urethane, FDA-grade, ESD/cleanroom, oil-resistant nitrile, applications above 5,000 lbs/caster, custom plate sizes, aerospace/nuclear/pharma compliance — submit your spec for engineering review. Same-day RFQ response.
Engineering Tools That Implement This Process
Caster Selection FAQ
What's the most common caster selection mistake?+
Sizing to the static load rating instead of the dynamic (rolling) load rating. Static = parked capacity; dynamic = in-motion capacity. Most failures trace to spec'ing against static and overloading the dynamic — particularly on dock plates, expansion joints, and shock-load environments. Always size to dynamic.
Why does the order of variables matter?+
Each variable narrows the next. If you pick wheel material before checking the floor, you might spec steel on epoxy (damages the floor). If you pick diameter before checking obstacles, you might violate the 4x rule. Sequential spec means each later choice has fewer valid options — preventing impossible combinations like "steel wheel on vinyl tile, 1500 lbs, 4 inch diameter."
When does ergonomic compliance enter the spec?+
After Steps 1-3. Once you have load + mount + material baseline, run the push force calc against OSHA 50-lb sustained limit (35 lb female). If exceeded, upgrade in this order: larger diameter (Step 4 bump up), low-resistance compound (MAX Efficiency 85A), aluminum hub, maintenance-free bearings. If still over after all four, you need powered drive — escalate to engineering.
How do I know when to escalate to a custom spec?+
Five triggers: load above 5,000 lbs/caster, custom durometer (60-95 Shore A outside standard 85A), FDA/conductive/ESD requirements, applications above 250°F, custom plate sizes (5"×7", 6"×8"). Standard catalog covers ~80% of industrial specs; the other 20% benefit from engineering review.
What size caster do I need for a 2,000 lb cart?
Use the W/(C-1)=R formula: total weight 2,000 lb divided by one less caster than you'll use (3 for a 4-caster cart) = 667 lb dynamic capacity needed per caster. Multiply by 1.5 safety factor: 1,000 lb per caster rating. Spec a 6 inch polyurethane on iron wheel, annular ball bearing, 4x4-1/2 plate. Above 2,500 lb dynamic per caster, switch to kingpinless with tapered roller.
How do I reduce push force on an existing cart?
Three high-leverage changes. Increase wheel diameter (each 1 inch increase drops push force ~10-15%). Upgrade bearings from plain to precision ball (drops push force 30-40%). Drop wheel durometer from 95A to 85A polyurethane (drops push force 15-20% but reduces capacity). Combined, a 4 inch plain-bearing 95A poly caster swapped for 6 inch precision-ball 85A poly can cut push force by half.
2 swivel + 2 rigid or 4 swivel?
2 swivel + 2 rigid for most industrial carts. Tracks straight, easier to control at speed, longer service life. 4 swivel only for light-duty carts (under 500 lb total), short runs, and applications where omnidirectional maneuverability matters more than tracking. Above walking speed (3 mph) or under heavy load, 4 swivel becomes unstable.
Do I need brakes on all 4 casters?
Two brakes diagonally opposed is the industrial standard. Hold the cart on level floors. For slopes, ramps, or staff leaning on the cart (medical, lab), spec total-lock (locks wheel AND swivel) on at least two casters. Four brakes for tow line carts where the cart is uncoupled and must hold position under bumping from other carts.
Related Resources
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