ASTM F2656 Bollards: K-Rating & M-Rating Explained

ASTM F2656 is the live-fire crash-test standard that defines anti-ram bollard performance. The standard rates bollards by vehicle class, speed, and penetration distance using M-nomenclature (M30, M40, M50) for the test vehicle, while the older K-rating system (K4, K8, K12) uses speed-only labels for legacy compatibility. Cojo specified K12 / M50 P1 bollards on a Salem federal-property perimeter in March 2026 because the project's threat assessment required full ASTM F2656 certification at 50 mph. This guide explains how the rating system works, how the K- and M-systems map to each other, and what the certification really proves.

For category context, see our What Are Bollards hub. For rating-by-rating cost, see Crash-Rated Bollard Cost. For nomenclature comparison, see K4 vs K8 vs K12 Bollards. For the low-speed companion standard, see ASTM F3016 Bollards Guide.

What Is ASTM F2656?

ASTM F2656 is the Standard Test Method for Crash Testing of Vehicle Security Barriers published by ASTM International. The current edition is F2656/F2656M-20, which superseded earlier F2656-07 and F2656-15 versions.

The standard defines:

• Vehicle class and weight (typically 15,000 lb medium-duty truck for K-rated work)
• Test speed (30, 40, or 50 mph)
• Penetration distance allowed (P1, P2, or P3)
• Test conditions (impact angle, surface, alignment)
• Pass/fail criteria

A bollard, wedge, gate, or beam barrier that survives the live-fire crash test under the standard's conditions earns a certification at that K-rating, M-rating, and penetration class.

Where Did K-Rating Come From?

The K-rating system originated with the U.S. State Department Specification SD-STD-02.01 Revision A, published in 1985 and revised through the 1990s and 2000s. State Department specs covered embassy and consular property perimeters and used a simple K4/K8/K12 label tied to test speed.

ASTM F2656 supplemented (and ultimately superseded for new specifications) the State Department spec by adding:

• M-rating that accounts for vehicle class as well as speed
• Penetration classes (P1, P2, P3) that distinguish low penetration from higher penetration
• Standardized test conditions

The federal government and most commercial specifications use F2656 for new installations as of 2020. Legacy K-rating language persists because so many existing specs reference it.

How Do K-Rating and M-Rating Map to Each Other?

K- and M-ratings cover the same test vehicle and the same test speeds, so the mapping is straightforward.

K-Rating	M-Rating	Test Vehicle	Test Speed
K4	M30	15,000 lb medium-duty truck	30 mph
K8	M40	15,000 lb medium-duty truck	40 mph
K12	M50	15,000 lb medium-duty truck	50 mph

For most bollard procurement specs, "K12" and "M50" mean the same crash performance. The difference is which test standard or specification document the spec was originally written under.

What Are the Penetration Classes?

ASTM F2656 adds penetration classes that the older K-rating system did not have. Penetration is measured from the original front face of the bollard to where the bed of the test vehicle came to rest.

Penetration Class	Distance	Application
P1	Less than 1 m (3.3 ft)	High-security federal, embassy perimeter
P2	1 m to 7 m (3.3 to 23 ft)	Most commercial high-risk applications
P3	7 m to 30 m (23 to 98 ft)	Lower-priority deflection use

P1 is the most expensive certification because the bollard must absorb essentially all impact energy at its location. P2 covers the majority of commercial K-rated procurement. P3 is appropriate for sites where the goal is deflection rather than full stop.

How Is the Certification Tested?

ASTM F2656 testing is performed at independent crash-test facilities such as the Texas Transportation Institute or the Karco facility. Testing covers:

1. Vehicle preparation. A 15,000-lb test vehicle is loaded to specified weight with ballast.
2. Site preparation. The bollard line is installed per the manufacturer's certified configuration on a test pad with documented soil and concrete conditions.
3. Impact alignment. The vehicle is towed or self-driven to the bollard line at the test speed, with impact aligned per the standard.
4. Measurement. Penetration distance, vehicle damage, bollard damage, and post-test condition are documented.
5. Certification. A pass at the tested speed and penetration class generates a certification document tied to that specific configuration.

The U.S. Department of State Diplomatic Security Bureau and the U.S. Department of Defense Unified Facilities Criteria reference ASTM F2656 testing for federal facility perimeter procurement.

Why Does Configuration Matter So Much?

ASTM F2656 certifications are configuration-specific. The certificate covers the exact bollard model, exact spacing, exact foundation, and exact installation method that was tested.

What Counts as Configuration?

• Bollard outside diameter and wall thickness
• Bollard above-grade height
• Foundation depth, width, and reinforcement
• Bollard-to-bollard spacing (center-to-center)
• Number of bollards in the tested line
• Anchor bolts, if any
• Underground cable connections, if any
• Concrete strength

Field installation that deviates from any of these voids the certification. A common mistake is widening the bollard spacing because the original spec did not match the site, then claiming K-rated protection on a configuration that was never tested.

For real-world Salem-area work where Cojo handles federal-property perimeter installs, see Bollard Installation Salem.

What Does an F2656 Certification Look Like?

A valid certification document includes:

• Manufacturer name and product designation
• Test facility and test date
• Vehicle class, weight, and speed
• K-rating and M-rating earned
• Penetration class earned (P1, P2, or P3)
• Configuration details (foundation, spacing, anchorage)
• Photographs of pre-test setup and post-test condition

Certifications older than 5 years should be reviewed against current standard editions. The standard does not require recertification on a fixed cycle, but specifications often require recent test data.

For maintenance after install, see our bollard curb stop painting service guide. The maintenance does not affect certification but does affect long-term performance.

When Should You Specify ASTM F2656 Over F3016?

ASTM F3016 is a separate low-speed crash-test standard for bollards in low-speed environments (10, 20, 30 mph). The two standards cover different threat profiles.

• Use F2656 when vehicle ramming above 30 mph is a credible threat. Federal facilities, high-occupancy venues, and high-risk commercial perimeters.
• Use F3016 when low-speed protection is sufficient. Drive-thrus, ATMs, school zones, and low-risk parking-lot perimeters.

Most parking-lot and storefront work does not require F2656. Most federal-facility perimeter work does. The threat assessment drives the choice -- spec'ing F2656 when F3016 is sufficient adds significant cost without proportional benefit.

Get an ASTM F2656 Specification Review

ASTM F2656 procurement is precise: the K-rating, M-rating, and penetration class together with the manufacturer's certified configuration drive the spec. Cojo specs and installs ASTM F2656 K4, K8, and K12 bollards across Oregon for federal-property and high-security commercial applications, including configuration verification. Contact Cojo for an F2656 specification review on your project.

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