Impact/Compression Specifications – ASTM 2413-11. All of Nautilus Safety Footwear and Avenger Work Boots products exceed all testing requirements for protective footwear impact and compression resistance. Protective footwear must pass two tests for impact and compression established by American Society for Testing and Materials (ASTM). Under the Class 75 test for impact, footwear must withstand a 75 lb. impact with 12.7 mm (0.50 in.) clearance for men’s and 11.9 mm (0.468 in.) for women’s. Under the Class 75 test for compression, footwear must withstand 2,500 lbs. of compression while maintaining at least 12.7 mm (0.50 in.) for men’s and 11.9 mm (0.468 in.) for women’s.