M-Ratings vs. K-Ratings Crash ratings are typically determined by three factors: How heavy the vehicle is How fast the vehicle is travelling How far past the barrier the vehicle travels K-Ratings (old ratings) The K-ratings were developed in 1985 (revised 2003) by the Department of State . The product was given certification based on how far the front bumper of a 15,000 lb. vehicle travelled past the barrier. The K-ratings also limited certification to 50' or less past the barrier. M-Ratings (new ratings) The new M-ratings have since replaced K-ratings and are governed by the American Society for Testing and Materials (ASTM). The primary difference is that certification is given based on how far the payload travels past the barrier. Additionally there is no limit to how far the vehicle can travel past the barrier to be certified. According to the ASTM, anything that travels beyond 98.41' can be given a P4 certification. The following infographic displays cerifitied and engineered (denoted by *) products. Shop products according to their crash ratings. Tested, Certified, Engineered and Equivalent Tested: Be warry of security products that only say crash tested. A product can be tested but not pass the test. Certified: A crash test certified product means that it passed the test and acheived the rating. Engineered: Engineered products have been engineered (calculations, designed, computer model tested) to meet a particular designation within a referenced standard. Equivalent: Because M-ratings and K-rating are so similar, a customer looking for an M50 certified product can also use a K12 certified product and achieve the same results. ASTM Vehicle Types The ASTM has developed crash certifications for different types of vehicles. They are as follows: C-ratings: small passenger car (2430 lb.) PU-ratings: pickup truck (5070 lb.) M-ratings: medium-duty truck (15,000 lb.) H-ratings: heavy goods vehicle (65,000 lb.) International Ratings Ameristar also offers several products that are crash test certified to international ratings such as PAS68 and IWA14. Equivalent ratings are noted on product pages if available. You can view these products here.