Flatbed Load Securement: FMCSA Rules You Must Know
Every flatbed driver — whether you run a skateboard, step deck, or lowboy — must comply with FMCSA cargo securement regulations. This guide covers 49 CFR 393.100-136 in plain language: tiedown counts, working load limits, chains vs straps, and how to pass every roadside inspection.
O Trucking Editorial Team
Trucking Industry Experts
Fact-Checked by O Trucking Dispatch Team
5+ years coordinating flatbed load securement and compliance across all equipment types
This article was written by the O Trucking editorial team with 9+ years of combined trucking industry experience. Learn more about us.
O TruckingFlatbed Load Securement: FMCSA Rules & Requirements (2026)
FMCSA Cargo Securement: The Core Rules
FMCSA cargo securement regulations are codified in 49 CFR Part 393, Subpart I (Sections 393.100 through 393.136). These rules apply to all commercial motor vehicles operating in interstate commerce, and they are based on the North American Cargo Securement Standard Model Regulations developed jointly by the U.S., Canada, and Mexico.
The fundamental principle is simple: cargo must be immovable. Specifically, cargo must be secured so it cannot shift or fall from the vehicle under all conditions of acceleration, deceleration, turning, and road surface irregularities that a driver would reasonably encounter during transit. FMCSA quantifies this as:
Forward restraint: Securement must withstand a deceleration force of 0.8g (80% of cargo weight) in the forward direction.
Rearward restraint: Securement must withstand a force of 0.5g (50% of cargo weight) in the rearward direction.
Lateral restraint: Securement must withstand a force of 0.5g (50% of cargo weight) to either side.
Vertical restraint: Securement must prevent cargo from bouncing or shifting upward, accounting for road surface irregularities.
Meeting these force requirements comes down to two things: the number of tiedowns and the aggregate working load limit of all tiedowns combined. FMCSA sets minimum requirements for both, and the driver must satisfy whichever standard requires more tiedowns.
Tiedown Count Rules (49 CFR 393.106)
FMCSA specifies the minimum number of tiedowns based on load length. These are absolute minimums that apply regardless of cargo weight:
| Article Length | Minimum Tiedowns | Example |
|---|---|---|
| 5 ft or shorter | 1 tiedown | Small compressor, single pallet |
| Over 5 ft to 10 ft | 2 tiedowns | HVAC unit, skid-mounted equipment |
| Over 10 ft | 2 + 1 per additional 10 ft | 20-ft steel beam = 3 tiedowns minimum |
For loads over 10 feet, the calculation is: 2 tiedowns for the first 10 feet, then 1 additional tiedown for each 10-foot increment (or fraction thereof). A 32-foot steel beam requires 2 + 3 = 5 tiedowns by the count rule. A 48-foot load of lumber requires 2 + 4 = 6 tiedowns minimum.
But the count rule is only one requirement. You must also meet the aggregate working load limit rule, which often requires more tiedowns than the count rule alone.
Working Load Limit Rule (Aggregate WLL)
The aggregate working load limit (WLL) of all tiedowns must equal at least 50% of the total cargo weight. Every tiedown device — chain, strap, wire rope, or cordage — has a rated WLL stamped or printed on it. You add up the WLL of every tiedown on the load, and the total must reach at least half the cargo weight.
Working Load Limit Example
Cargo weight: 40,000 lbs
Required aggregate WLL: 40,000 x 50% = 20,000 lbs
Using 3/8" Grade 70 chain (WLL: 6,600 lbs each):
20,000 / 6,600 = 3.03 — round up to 4 chains minimum
Using 4" polyester straps (WLL: 5,400 lbs each):
20,000 / 5,400 = 3.70 — round up to 4 straps minimum
In practice, experienced flatbed drivers apply significantly more tiedowns than the legal minimum. A 40,000-pound steel coil may legally require only 4 chains, but most drivers use 6-8 chains plus coil racks for stability. The legal minimum keeps you compliant at the scale, but proper securement keeps you safe on the road. A load that shifts mid-transit can cause a rollover, which no amount of legal compliance prevents if the securement was merely adequate rather than thorough.
Both Rules Apply Simultaneously
Chains vs Straps: When to Use Each
The two primary tiedown types for flatbed work are Grade 70 transport chain and 4-inch polyester web straps. Each has advantages and specific use cases:
Grade 70 Transport Chain
WLL (common sizes):
- 5/16" chain: 4,700 lbs WLL
- 3/8" chain: 6,600 lbs WLL
- 1/2" chain: 11,300 lbs WLL
Best for: Steel (coils, beams, plate), concrete products, heavy machinery, anything with sharp edges that would cut a strap
Pros: Cannot be cut by sharp edges, highest WLL per tiedown, long lifespan, UV-resistant
Cons: Heavy (20-40 lbs per chain assembly), can scratch painted surfaces, slower to apply, requires binders
4-Inch Polyester Web Straps
WLL (common ratings):
- 4" strap with flat hook: 5,400 lbs WLL
- 4" strap with ratchet: 5,400 lbs WLL
- 2" strap (lighter duty): 3,333 lbs WLL
Best for: Lumber, manufactured goods, palletized freight, light machinery, coated or painted items
Pros: Lightweight (3-5 lbs each), faster to apply and remove, gentler on cargo surfaces, easy to store
Cons: Can be cut by sharp edges, degrades in UV light over time, lower WLL than chain, must be replaced when frayed
Chain Binder Types: Ratchet vs Lever
Securement by Load Type
FMCSA has commodity-specific securement rules for certain load types. These are in addition to the general rules and provide specific requirements for commonly hauled flatbed freight:
Metal Coils (49 CFR 393.120)
Steel coils have their own FMCSA rule because they are extremely heavy, cylindrical, and prone to rolling. Coils must be secured with a minimum of one chain over the top (for coils with eyes vertical) or through the center (for coils with eyes crosswise or lengthwise). The specific tiedown configuration depends on coil orientation and weight. Coil racks or cradles are used to prevent rolling. A single unrestrained 40,000-pound steel coil can roll off a flatbed in a hard turn, which is why coil securement rules are the most specific in the FMCSA regulations.
Logs and Lumber (49 CFR 393.116/118)
Lumber bundles must be restrained against forward, rearward, and lateral movement. Bundles are typically stacked and secured with straps every 10 feet. The bottom tier must be blocked or secured to prevent forward movement. Stacked tiers must be cross-tied or secured to prevent the upper tiers from shifting independently. Dunnage (spacer boards) between tiers allows straps to grip the load rather than just the top tier.
Concrete Pipe and Products (49 CFR 393.132)
Concrete pipe, blocks, and panels have specific securement methods based on whether the pipes are stacked or in a single layer. Pipes must be cradled or wedged to prevent rolling. Stacked pipes require blocking between tiers. The aggregate WLL rule applies, and because concrete is heavy, most pipe loads require numerous tiedowns to meet the 50% WLL requirement.
Machinery and Equipment (General Rules)
There is no commodity-specific rule for general machinery, so the general securement rules apply. Chain the machine down at four points minimum (four corners), ensure the aggregate WLL meets 50% of the equipment weight, and block the equipment against forward movement. If the machine has tracks, wheels, or tires, those must be individually secured to prevent rolling or bouncing. Rubber-tired equipment must be deflated or have wheel chocks in addition to chain tiedowns.
Passing Roadside Inspections: Securement Checklist
DOT officers at roadside inspections and weigh stations check cargo securement as part of Level 1 and Level 2 inspections. Securement violations are among the most common out-of-service findings for flatbed trucks. Here is what inspectors look for:
Tiedown count and placement — Correct number of tiedowns per the count rule, evenly spaced along the load length.
Aggregate WLL — Inspector calculates whether total WLL of all tiedowns meets the 50% cargo weight requirement.
Tiedown condition — No frayed straps, no cracked chain links, no bent hooks, no damaged ratchets. Any damaged tiedown is considered non-functional.
Tiedown tension — All tiedowns must be taut with no slack. Inspector can physically check by pulling on the strap or chain.
Edge protectors — Present wherever tiedowns pass over sharp edges. Missing edge protectors on strap loads are an immediate violation.
WLL markings — All tiedowns must have legible WLL markings. If the WLL stamp is worn off a chain or the strap label is missing, the inspector treats it as zero WLL.
No cargo shift — Load has not shifted from its original position. Evidence of shifting (marks on the deck, displaced dunnage) triggers further inspection.
First 50 Miles: Re-Check Your Securement
Essential Flatbed Securement Equipment
Every flatbed driver needs a full complement of securement equipment on the truck at all times. Running out of straps mid-trip or showing up to a steel load without enough chains means either refusing the load or making a dangerous compromise. Here is the standard flatbed securement kit:
Minimum Equipment List
The total cost for a complete securement kit runs $2,500-$4,000 depending on brand and quantity. This is a non-negotiable investment for flatbed work. Carriers who cut corners on securement equipment end up with CSA violations, out-of-service orders, and — in the worst cases — catastrophic load loss incidents that result in fatalities, lawsuits, and insurance cancellation.
Flatbed Securement FAQ
Common questions about FMCSA cargo securement rules for flatbed trailers
How many tiedowns do I need for a flatbed load?
Under FMCSA rules (49 CFR 393.106), you need at least one tiedown for loads 5 feet or shorter and at least two tiedowns for loads longer than 5 feet but no more than 10 feet. For loads over 10 feet, you need two tiedowns for the first 10 feet plus one additional tiedown for every additional 10 feet or fraction thereof. Separately, the total working load limit of all tiedowns must equal at least 50% of the cargo weight. You must meet BOTH requirements — the count rule AND the weight rule. Whichever rule requires more tiedowns is the minimum you need.
Should I use chains or straps for flatbed securement?
It depends on the load. Chains (Grade 70 transport chain) are required for heavy, hard-surface loads like steel coils, steel beams, concrete barriers, and heavy machinery. Chains have a higher working load limit (4,700-6,600 lbs per chain for common sizes) and will not cut or abrade on sharp metal edges. Straps (4-inch polyester webbing) are used for lumber, manufactured goods, palletized freight, and lighter machinery. Straps are faster to apply and lighter to handle, but they will be cut by sharp edges and can degrade in UV light over time. Many loads use both: chains on the heavy or sharp portions and straps on lighter sections.
What is the FMCSA penalty for improper cargo securement?
FMCSA cargo securement violations fall under 49 CFR 393.100-136. A Level 1 or Level 2 roadside inspection finding insufficient tiedowns can result in an out-of-service order — meaning you cannot move the truck until the securement is corrected. Fines range from $1,000-$16,000 per violation depending on severity. Cargo securement violations also add points to your CSA score in the Vehicle Maintenance BASIC category, which can trigger FMCSA intervention if your score exceeds the threshold. Multiple violations can result in a carrier safety audit.
Do I need edge protectors on every flatbed load?
Edge protectors are not universally required by FMCSA regulations, but they are required whenever a tiedown passes over a sharp edge that could cut or damage the tiedown. In practice, you need edge protectors on almost every flatbed load that uses straps, because even lumber corners and pallet edges can abrade polyester webbing under tension. Chains do not require edge protectors but should have rubber guards on painted or finished surfaces to prevent scratching. Professional flatbed drivers carry a minimum of 20-30 edge protectors at all times and use them on every load.
Our Dispatchers Prioritize Load Safety
We match flatbed loads to carriers who have the right equipment and securement experience. Compliance and safety are not optional — they are the foundation of every load we book.